Weld Joints Definition and purposes:
Weld joints are designed to transfer the stresses between the members of the joint. Forces and loads are introduces at different point and are transmitted different parts of weld.
Types : All weld joints classified into different types.
1) Full Penetration
2) Partial penetration Joints
Remember: When joints are subjected to dynamic loading reversing loads, and impact loads, the weld should be very efficient. Such services require full-penetration welds. The strength of weld joints not only on the size of the weld but also on the strength of the weld metal.
What is definition of Stress?
Answer: A bad form of “flexibility” called Stress.
How can you evaluate current after performing welding?
Answer: you can evaluate of current through “Ripples”. It is a best source to know that.
Metal Active Gas welding:
1) Simple edge preparation
2) 2 pass welding
3) Less wire electrode
4) No slag removal
5) High deposition rate
6) High deposition efficiency
Shielded Arc Welding:
1) V groove
2) 5 Pass welding
3) More electrode consumption
Reference by: welding books
Test positions for Lap, Butt, Scarf Rabbet Joints:
Flat Flow position:
The test joints in position suitable for applying brazing filler metal in rod, strip, or other suitable form.
Vertical down flow position:
The test joints in position suitable for applying brazing filler metal in rod, strip, or other suitable form.
Vertical Up flow position:
The test joints in position suitable for applying brazing filler metal in rod, strip or other suitable form.
Horizontal flow position:
The test joins in position suitable for applying brazing filler metal in rod, strip or other suitable form.
Tension Test:
Used to determine the ultimate strength of brazed butt, scarf, lap and rabbet joints.
Guided Bend Test:
Used to determine the degree of soundness and ductility of butt and scarf joints
Wednesday, November 11, 2009
NDT Mechanical Testing
NDT Mechanical Testing
To establish the level of mechanical properties
Which properties?
1) Hardness
2) Toughness
3) Tensile Strength
4) Ductility
Introduction to Mechanical Testing
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint
We divide tests into Quantitative & Qualitative methods.
1) Quantitative Tests: ( Have units)
2) Qualitative Tests: ( Have no units)
Types of Tests include:
1) Quantitative Tests:
Hardness tests
Toughness tests
Tensile strength tests
2) Qualitative Tests:
Macro Tests
Bend Tests
Fracture tests
Testing the Weldment
Charpy V Test : For Tensile Test
Bend Test: Macro / Hardness Test
Hardness Testing:
Generally we use a diamond or steel ball to form an indentation. We measure the width of the indentation to gauge the hardness.
Hardness Testing:
1) Vickers Diamond: Always uses a diamond
2) Brinell Hardness test: Always uses a steel ball
3) Rockwell hardness test: Uses a ball, or diamond depending on the scale
Toughness Testing:
1) Charpy V Test: 11x10 ( Specimen horizontal) Joules
2) Izod test: 12x10 ( Specimen vertical) ft. lbs
3) CTOD test: Specimen used is actual design size detailed fracture report. mm
Transverse Tensile Test:
A section of weld is cut, or machined out across the test piece and tested in tension to failure. The units are usually in N/mm
Ductility Elongation:
Firstly, before the tensile test 2 marks are made 50mm apart. During the test, Yield point & Tensile strength are measured. The Specimen is put together and the marks are re-measured.
A new measurement of 75mm will indicate Elongation E50%
Macro Inspection:
1) Excess weld metal height
2) Lack of sidewall fusion
3) Lack of Root fusion
4) Slag inclusion & Lack of inter-run fusion
5) Poor Toe blend
6) Laminations
7) Porosity
8) Root penetration
Bend Tests:
Bend tests are used to establish fusion in the area under test. Further tests include face, side and longitudinal bend tests. For material over 15mm thickness, side bend test may be used.
Mechanical Testing:
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint.
We divide tests into Qualitative & Quantitative methods.
Macro Inspection:
The main difference between Macro & Micro is that Micro is the study of the micro-structure at much higher magnification.
The limit of Macro inspection is magnification< X15
The specimen is usually cut from a stop / start in the test piece
The Cut specimen is polished to a fine finish ( 530 grit)
The specimen must be inspected, before etching.
Welding Procedures:
A definition of the term “Procedure”
A systematic method of producing an aim
Therefore, a “Welding Procedure”
A systematic method of producing a sound weld
Most production welding procedures are formatted on written documents or computer spreadsheets, but they need not be written and may be a product of experience.
Most procedures are approved, but not all. An approved welding procedure is one that has been tested to ensure that the procedure as carried out, produces a weld that ensure that the procedure as carried out, produces a weld that satisfies a minimum level of quality for the mechanical, physical or chemical properties desired. If these are not required, then “Procedural approval is unnecessary”
A welding procedure is a recipe of variable parameters, which will produce the same results of certain quality & Properties if carried out in the same way each time. To evaluate a provisional welding procedure we need to check if all the parameters set will work together to produce the desired results.
Once the weld has been completed it is usually visually inspected, then Radiography or Ultrasonic testing is usually applied.
Finally, and most importantly, mechanically tested to ensure that the desire level of mechanical properties have been met.
If all the desired properties have been met, then a procedure qualification record is completed will all the test results.
Contents of Approval:
1) Diameter of pipe, or thickness of plate
2) Welding position, amperage range, or number of runs
3) Process( On multi process procedures only)
4) Certain material groups
5) Heat input rang (Kj/mm)
Welding Positions for Butt welds:
Graphical Representation:
1 G Flat Position (Rotated)
2 G Horizontal Position (Vertical position)
3 G Vertical position
4 G Overhead position
5 G Vertical position (PF Vertical up, PG Vertical down)
6 G Inclined position
Fillet welds:
1 F Flat position 45 degree
1FR (Rotated)
2F Horizontal vertical position
2FR (Pipe axis horizontal)
3F weld throat vertical
4F Weld axis horizontal ( Overhead position)
5F Pipe axis horizontal ( Vertical position, PG: Vertical Up, PG: Vertical down)
Reference by: welding books
To establish the level of mechanical properties
Which properties?
1) Hardness
2) Toughness
3) Tensile Strength
4) Ductility
Introduction to Mechanical Testing
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint
We divide tests into Quantitative & Qualitative methods.
1) Quantitative Tests: ( Have units)
2) Qualitative Tests: ( Have no units)
Types of Tests include:
1) Quantitative Tests:
Hardness tests
Toughness tests
Tensile strength tests
2) Qualitative Tests:
Macro Tests
Bend Tests
Fracture tests
Testing the Weldment
Charpy V Test : For Tensile Test
Bend Test: Macro / Hardness Test
Hardness Testing:
Generally we use a diamond or steel ball to form an indentation. We measure the width of the indentation to gauge the hardness.
Hardness Testing:
1) Vickers Diamond: Always uses a diamond
2) Brinell Hardness test: Always uses a steel ball
3) Rockwell hardness test: Uses a ball, or diamond depending on the scale
Toughness Testing:
1) Charpy V Test: 11x10 ( Specimen horizontal) Joules
2) Izod test: 12x10 ( Specimen vertical) ft. lbs
3) CTOD test: Specimen used is actual design size detailed fracture report. mm
Transverse Tensile Test:
A section of weld is cut, or machined out across the test piece and tested in tension to failure. The units are usually in N/mm
Ductility Elongation:
Firstly, before the tensile test 2 marks are made 50mm apart. During the test, Yield point & Tensile strength are measured. The Specimen is put together and the marks are re-measured.
A new measurement of 75mm will indicate Elongation E50%
Macro Inspection:
1) Excess weld metal height
2) Lack of sidewall fusion
3) Lack of Root fusion
4) Slag inclusion & Lack of inter-run fusion
5) Poor Toe blend
6) Laminations
7) Porosity
8) Root penetration
Bend Tests:
Bend tests are used to establish fusion in the area under test. Further tests include face, side and longitudinal bend tests. For material over 15mm thickness, side bend test may be used.
Mechanical Testing:
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint.
We divide tests into Qualitative & Quantitative methods.
Macro Inspection:
The main difference between Macro & Micro is that Micro is the study of the micro-structure at much higher magnification.
The limit of Macro inspection is magnification< X15
The specimen is usually cut from a stop / start in the test piece
The Cut specimen is polished to a fine finish ( 530 grit)
The specimen must be inspected, before etching.
Welding Procedures:
A definition of the term “Procedure”
A systematic method of producing an aim
Therefore, a “Welding Procedure”
A systematic method of producing a sound weld
Most production welding procedures are formatted on written documents or computer spreadsheets, but they need not be written and may be a product of experience.
Most procedures are approved, but not all. An approved welding procedure is one that has been tested to ensure that the procedure as carried out, produces a weld that ensure that the procedure as carried out, produces a weld that satisfies a minimum level of quality for the mechanical, physical or chemical properties desired. If these are not required, then “Procedural approval is unnecessary”
A welding procedure is a recipe of variable parameters, which will produce the same results of certain quality & Properties if carried out in the same way each time. To evaluate a provisional welding procedure we need to check if all the parameters set will work together to produce the desired results.
Once the weld has been completed it is usually visually inspected, then Radiography or Ultrasonic testing is usually applied.
Finally, and most importantly, mechanically tested to ensure that the desire level of mechanical properties have been met.
If all the desired properties have been met, then a procedure qualification record is completed will all the test results.
Contents of Approval:
1) Diameter of pipe, or thickness of plate
2) Welding position, amperage range, or number of runs
3) Process( On multi process procedures only)
4) Certain material groups
5) Heat input rang (Kj/mm)
Welding Positions for Butt welds:
Graphical Representation:
1 G Flat Position (Rotated)
2 G Horizontal Position (Vertical position)
3 G Vertical position
4 G Overhead position
5 G Vertical position (PF Vertical up, PG Vertical down)
6 G Inclined position
Fillet welds:
1 F Flat position 45 degree
1FR (Rotated)
2F Horizontal vertical position
2FR (Pipe axis horizontal)
3F weld throat vertical
4F Weld axis horizontal ( Overhead position)
5F Pipe axis horizontal ( Vertical position, PG: Vertical Up, PG: Vertical down)
Reference by: welding books
NDT Mechanical Testing
NDT Mechanical Testing
To establish the level of mechanical properties
Which properties?
1) Hardness
2) Toughness
3) Tensile Strength
4) Ductility
Introduction to Mechanical Testing
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint
We divide tests into Quantitative & Qualitative methods.
1) Quantitative Tests: ( Have units)
2) Qualitative Tests: ( Have no units)
Types of Tests include:
1) Quantitative Tests:
Hardness tests
Toughness tests
Tensile strength tests
2) Qualitative Tests:
Macro Tests
Bend Tests
Fracture tests
Testing the Weldment
Charpy V Test : For Tensile Test
Bend Test: Macro / Hardness Test
Hardness Testing:
Generally we use a diamond or steel ball to form an indentation. We measure the width of the indentation to gauge the hardness.
Hardness Testing:
1) Vickers Diamond: Always uses a diamond
2) Brinell Hardness test: Always uses a steel ball
3) Rockwell hardness test: Uses a ball, or diamond depending on the scale
Toughness Testing:
1) Charpy V Test: 11x10 ( Specimen horizontal) Joules
2) Izod test: 12x10 ( Specimen vertical) ft. lbs
3) CTOD test: Specimen used is actual design size detailed fracture report. mm
Transverse Tensile Test:
A section of weld is cut, or machined out across the test piece and tested in tension to failure. The units are usually in N/mm
Ductility Elongation:
Firstly, before the tensile test 2 marks are made 50mm apart. During the test, Yield point & Tensile strength are measured. The Specimen is put together and the marks are re-measured.
A new measurement of 75mm will indicate Elongation E50%
Macro Inspection:
1) Excess weld metal height
2) Lack of sidewall fusion
3) Lack of Root fusion
4) Slag inclusion & Lack of inter-run fusion
5) Poor Toe blend
6) Laminations
7) Porosity
8) Root penetration
Bend Tests:
Bend tests are used to establish fusion in the area under test. Further tests include face, side and longitudinal bend tests. For material over 15mm thickness, side bend test may be used.
Mechanical Testing:
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint.
We divide tests into Qualitative & Quantitative methods.
Macro Inspection:
The main difference between Macro & Micro is that Micro is the study of the micro-structure at much higher magnification.
The limit of Macro inspection is magnification< X15
The specimen is usually cut from a stop / start in the test piece
The Cut specimen is polished to a fine finish ( 530 grit)
The specimen must be inspected, before etching.
Welding Procedures:
A definition of the term “Procedure”
A systematic method of producing an aim
Therefore, a “Welding Procedure”
A systematic method of producing a sound weld
Most production welding procedures are formatted on written documents or computer spreadsheets, but they need not be written and may be a product of experience.
Most procedures are approved, but not all. An approved welding procedure is one that has been tested to ensure that the procedure as carried out, produces a weld that ensure that the procedure as carried out, produces a weld that satisfies a minimum level of quality for the mechanical, physical or chemical properties desired. If these are not required, then “Procedural approval is unnecessary”
A welding procedure is a recipe of variable parameters, which will produce the same results of certain quality & Properties if carried out in the same way each time. To evaluate a provisional welding procedure we need to check if all the parameters set will work together to produce the desired results.
Once the weld has been completed it is usually visually inspected, then Radiography or Ultrasonic testing is usually applied.
Finally, and most importantly, mechanically tested to ensure that the desire level of mechanical properties have been met.
If all the desired properties have been met, then a procedure qualification record is completed will all the test results.
Contents of Approval:
1) Diameter of pipe, or thickness of plate
2) Welding position, amperage range, or number of runs
3) Process( On multi process procedures only)
4) Certain material groups
5) Heat input rang (Kj/mm)
Welding Positions for Butt welds:
Graphical Representation:
1 G Flat Position (Rotated)
2 G Horizontal Position (Vertical position)
3 G Vertical position
4 G Overhead position
5 G Vertical position (PF Vertical up, PG Vertical down)
6 G Inclined position
Fillet welds:
1 F Flat position 45 degree
1FR (Rotated)
2F Horizontal vertical position
2FR (Pipe axis horizontal)
3F weld throat vertical
4F Weld axis horizontal ( Overhead position)
5F Pipe axis horizontal ( Vertical position, PG: Vertical Up, PG: Vertical down)
Reference by: welding books
To establish the level of mechanical properties
Which properties?
1) Hardness
2) Toughness
3) Tensile Strength
4) Ductility
Introduction to Mechanical Testing
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint
We divide tests into Quantitative & Qualitative methods.
1) Quantitative Tests: ( Have units)
2) Qualitative Tests: ( Have no units)
Types of Tests include:
1) Quantitative Tests:
Hardness tests
Toughness tests
Tensile strength tests
2) Qualitative Tests:
Macro Tests
Bend Tests
Fracture tests
Testing the Weldment
Charpy V Test : For Tensile Test
Bend Test: Macro / Hardness Test
Hardness Testing:
Generally we use a diamond or steel ball to form an indentation. We measure the width of the indentation to gauge the hardness.
Hardness Testing:
1) Vickers Diamond: Always uses a diamond
2) Brinell Hardness test: Always uses a steel ball
3) Rockwell hardness test: Uses a ball, or diamond depending on the scale
Toughness Testing:
1) Charpy V Test: 11x10 ( Specimen horizontal) Joules
2) Izod test: 12x10 ( Specimen vertical) ft. lbs
3) CTOD test: Specimen used is actual design size detailed fracture report. mm
Transverse Tensile Test:
A section of weld is cut, or machined out across the test piece and tested in tension to failure. The units are usually in N/mm
Ductility Elongation:
Firstly, before the tensile test 2 marks are made 50mm apart. During the test, Yield point & Tensile strength are measured. The Specimen is put together and the marks are re-measured.
A new measurement of 75mm will indicate Elongation E50%
Macro Inspection:
1) Excess weld metal height
2) Lack of sidewall fusion
3) Lack of Root fusion
4) Slag inclusion & Lack of inter-run fusion
5) Poor Toe blend
6) Laminations
7) Porosity
8) Root penetration
Bend Tests:
Bend tests are used to establish fusion in the area under test. Further tests include face, side and longitudinal bend tests. For material over 15mm thickness, side bend test may be used.
Mechanical Testing:
We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint.
We divide tests into Qualitative & Quantitative methods.
Macro Inspection:
The main difference between Macro & Micro is that Micro is the study of the micro-structure at much higher magnification.
The limit of Macro inspection is magnification< X15
The specimen is usually cut from a stop / start in the test piece
The Cut specimen is polished to a fine finish ( 530 grit)
The specimen must be inspected, before etching.
Welding Procedures:
A definition of the term “Procedure”
A systematic method of producing an aim
Therefore, a “Welding Procedure”
A systematic method of producing a sound weld
Most production welding procedures are formatted on written documents or computer spreadsheets, but they need not be written and may be a product of experience.
Most procedures are approved, but not all. An approved welding procedure is one that has been tested to ensure that the procedure as carried out, produces a weld that ensure that the procedure as carried out, produces a weld that satisfies a minimum level of quality for the mechanical, physical or chemical properties desired. If these are not required, then “Procedural approval is unnecessary”
A welding procedure is a recipe of variable parameters, which will produce the same results of certain quality & Properties if carried out in the same way each time. To evaluate a provisional welding procedure we need to check if all the parameters set will work together to produce the desired results.
Once the weld has been completed it is usually visually inspected, then Radiography or Ultrasonic testing is usually applied.
Finally, and most importantly, mechanically tested to ensure that the desire level of mechanical properties have been met.
If all the desired properties have been met, then a procedure qualification record is completed will all the test results.
Contents of Approval:
1) Diameter of pipe, or thickness of plate
2) Welding position, amperage range, or number of runs
3) Process( On multi process procedures only)
4) Certain material groups
5) Heat input rang (Kj/mm)
Welding Positions for Butt welds:
Graphical Representation:
1 G Flat Position (Rotated)
2 G Horizontal Position (Vertical position)
3 G Vertical position
4 G Overhead position
5 G Vertical position (PF Vertical up, PG Vertical down)
6 G Inclined position
Fillet welds:
1 F Flat position 45 degree
1FR (Rotated)
2F Horizontal vertical position
2FR (Pipe axis horizontal)
3F weld throat vertical
4F Weld axis horizontal ( Overhead position)
5F Pipe axis horizontal ( Vertical position, PG: Vertical Up, PG: Vertical down)
Reference by: welding books
Duties of a Welding Inspector
Duties of a Welding Inspector
Discuss the following
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Discuss the following
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Duties of a Welding Inspector
Duties of a Welding Inspector
Discuss the following
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Discuss the following
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Thursday, November 5, 2009
Non Destructive Testing
NON DESTRUCTIVE TESTING:
NDT testing uses for to access the quality of a component without destructing.
The four principles methods of Non Destructive Testing are mentioned below:
1) Penetrant Testing
2) Magnetic Particle Testing
3) Ultrasonic Testing
4) Radiographic Testing
A good NDT operator has both knowledge and experience, however some of the above techniques are more reliant on these factors.
Liquid Penetrant Testing:
Advantage:
1) Low operator skill level required
2) Used on Non-Ferromagnetic
3) Very cheep cost
4) Simple, easy and cheap to explain or interpreting
Disadvantages:
1) Careful surface preparation
2) Surface breaking flaws only
3) Not used on porous material
4) No permanent record
Magnetic Particle Testing:
Especially used for surface and sub-surface defects in ferrous materials
Advantages:
1) Detect some sub-surface defects
2) Very low cost
3) Simple apparatus or equipment
4) Especially use for thin coatings
Disadvantages:
1) Ferrous materials only
2) Demagnetisation required
3) Direct current flow may cause ARC STRIKES
4) No Permanent Record
5) Must applicable in two directions
Ultrasonic Testing:
Apply to the test surface required: (water, Oil, Grease)
Advantage:
1) Can easily detect lack of sidewall fusion
2) Ferrous and Non-ferrous alloys
3) No Major safety required
4) Portable
5) Able to detect any size of sub-surface defects
Disadvantages:
1) High operator skill required
2) Very expensive
3) Very difficult to interpreting
4) Very difficult for applying
Some Useful Tips about the terms and definitions of Weld and Joints
Weld: A union of materials, produced by heat or pressure
Joint: Configuration of members
Weld Preparation: Preparing a joint to allow access & fusion through the joint faces
Types of weld: Butt, Fillet, Stud, Forge, Seam, Edge, Slot, Flash butt
Types of joint: Butt, T. Lap, Open Corner, Closed corner.
Types of preparation: Bevel’s, V’s, J’s, U’s
Preparation Terms: Bevel angle, Root face, Root gap
Weldment Terms: Weld face, weld root, fusion zone, Weld toes, weld width. Fusion boundary
Weld Sizing (Butt): Design throat thickness, Excess weld metal.
Weld Sizing: (Fillets): Design throat thickness. Actual throat thickness, Excess weld metal, Leg length
Posted by: Zaman
NDT testing uses for to access the quality of a component without destructing.
The four principles methods of Non Destructive Testing are mentioned below:
1) Penetrant Testing
2) Magnetic Particle Testing
3) Ultrasonic Testing
4) Radiographic Testing
A good NDT operator has both knowledge and experience, however some of the above techniques are more reliant on these factors.
Liquid Penetrant Testing:
Advantage:
1) Low operator skill level required
2) Used on Non-Ferromagnetic
3) Very cheep cost
4) Simple, easy and cheap to explain or interpreting
Disadvantages:
1) Careful surface preparation
2) Surface breaking flaws only
3) Not used on porous material
4) No permanent record
Magnetic Particle Testing:
Especially used for surface and sub-surface defects in ferrous materials
Advantages:
1) Detect some sub-surface defects
2) Very low cost
3) Simple apparatus or equipment
4) Especially use for thin coatings
Disadvantages:
1) Ferrous materials only
2) Demagnetisation required
3) Direct current flow may cause ARC STRIKES
4) No Permanent Record
5) Must applicable in two directions
Ultrasonic Testing:
Apply to the test surface required: (water, Oil, Grease)
Advantage:
1) Can easily detect lack of sidewall fusion
2) Ferrous and Non-ferrous alloys
3) No Major safety required
4) Portable
5) Able to detect any size of sub-surface defects
Disadvantages:
1) High operator skill required
2) Very expensive
3) Very difficult to interpreting
4) Very difficult for applying
Some Useful Tips about the terms and definitions of Weld and Joints
Weld: A union of materials, produced by heat or pressure
Joint: Configuration of members
Weld Preparation: Preparing a joint to allow access & fusion through the joint faces
Types of weld: Butt, Fillet, Stud, Forge, Seam, Edge, Slot, Flash butt
Types of joint: Butt, T. Lap, Open Corner, Closed corner.
Types of preparation: Bevel’s, V’s, J’s, U’s
Preparation Terms: Bevel angle, Root face, Root gap
Weldment Terms: Weld face, weld root, fusion zone, Weld toes, weld width. Fusion boundary
Weld Sizing (Butt): Design throat thickness, Excess weld metal.
Weld Sizing: (Fillets): Design throat thickness. Actual throat thickness, Excess weld metal, Leg length
Posted by: Zaman
Welding/ Weld Defects/Post Weld Heat Treatment/Electrode/Filler Wire
Q#1: What do you mean by following type of welding?
(A) SMAW, ( B) TIG
Ans: SMAW: Shielded Metal Arc Welding
TIG: Tungsten Inert Gas Welding
Q#2: While welding of pipe trunion to pipe / reinforcement pad you have to put a hole or leave some portion of welding why?
Ans: For venting of hot gas which may get generated due to welding.
Q#3: What is the thumb rule to calculate Current required for welding?
Ans: Current( Amp) = ( Diameter of Electrode(mm) X 40)
Q#4: What is the minimum thickness of CS pipe that requires stress relieving to be done as per B 31.3 ?
Ans: 19.05mm thk.
Q#5: What are the common welding defects?
Ans: 1: Lack of Penetration
2: Lack of fusion
3: Under cut
4: Slag Inclusion
5: Porosity
6: Crack
7: Faulty weld size & Profile
8: Distortion
A: Lack of penetration:
This defects occurs at the roof of the joint when the weld metal fails to reach it or weld metal fails to fuse completely the root faces of the joint. As a result, a void remains at the root zone, which may contain slag inclusion.
Cause: (A) : Use of incorrect size of electrode in relation to the form of joint
(B): Low welding undercut
(C): Faulty fit-up and inaccurate joint preparation
B: Lack of fusion:
Lack of fusion is defined as a condition where boundaries of unfused metal exist between the weld metal a base metal or between the adjacent layers of weld metals.
Cause:
A) Presence of scale, dirt, oxide, slage and other non-metallic substance which prevents the weld metal to reach melting temperature.
B) Improper deslagging between the weld pass.
Precaution:-
A) Keep the weld joint free from scale, dirt, oxide, slag and other non-metallic substance.
B) Use adequate welding current
C) Deslag each weld pass thoroughly
D) Place weld passes correctly next to each other
Under Cut:
This defect appears as a continuous or discontinuous groove at the toes of a weld pass and located on the base metal or in the fusion face of a multipass weld. It occurs prominently on the edge of a fillet weld deposited in the horizontal position.
Cause:
A) Excessive welding current
B) Too high speed of arc travel
C) Wrong electorde angle
Rectification:-
The defect is rectified by filling the undercut groove with a weld pass. If undercut is deep & contains slag. It should be chipped away before rewelding.
(A) SMAW, ( B) TIG
Ans: SMAW: Shielded Metal Arc Welding
TIG: Tungsten Inert Gas Welding
Q#2: While welding of pipe trunion to pipe / reinforcement pad you have to put a hole or leave some portion of welding why?
Ans: For venting of hot gas which may get generated due to welding.
Q#3: What is the thumb rule to calculate Current required for welding?
Ans: Current( Amp) = ( Diameter of Electrode(mm) X 40)
Q#4: What is the minimum thickness of CS pipe that requires stress relieving to be done as per B 31.3 ?
Ans: 19.05mm thk.
Q#5: What are the common welding defects?
Ans: 1: Lack of Penetration
2: Lack of fusion
3: Under cut
4: Slag Inclusion
5: Porosity
6: Crack
7: Faulty weld size & Profile
8: Distortion
A: Lack of penetration:
This defects occurs at the roof of the joint when the weld metal fails to reach it or weld metal fails to fuse completely the root faces of the joint. As a result, a void remains at the root zone, which may contain slag inclusion.
Cause: (A) : Use of incorrect size of electrode in relation to the form of joint
(B): Low welding undercut
(C): Faulty fit-up and inaccurate joint preparation
B: Lack of fusion:
Lack of fusion is defined as a condition where boundaries of unfused metal exist between the weld metal a base metal or between the adjacent layers of weld metals.
Cause:
A) Presence of scale, dirt, oxide, slage and other non-metallic substance which prevents the weld metal to reach melting temperature.
B) Improper deslagging between the weld pass.
Precaution:-
A) Keep the weld joint free from scale, dirt, oxide, slag and other non-metallic substance.
B) Use adequate welding current
C) Deslag each weld pass thoroughly
D) Place weld passes correctly next to each other
Under Cut:
This defect appears as a continuous or discontinuous groove at the toes of a weld pass and located on the base metal or in the fusion face of a multipass weld. It occurs prominently on the edge of a fillet weld deposited in the horizontal position.
Cause:
A) Excessive welding current
B) Too high speed of arc travel
C) Wrong electorde angle
Rectification:-
The defect is rectified by filling the undercut groove with a weld pass. If undercut is deep & contains slag. It should be chipped away before rewelding.
Wednesday, November 4, 2009
NDT PIPING QUESTIONAIRE
Q#1: What is the ASME code followed for design of piping systems in Process piping(Refineries & Chemical Industries)?
Ans: B 31. 3
Q#2: Which American Institute Standard does Piping Engineer refer?
Ans: API, AISI, ASTM, ANSI, AWS, AWWA, ASME
Q#3: What is the different ASME 31 Code for pressure piping?
Ans: ASME B 31.1 - Power Piping
ASME B 31.2 - Fuel Gas Piping
ASME B 31.3 - Process Piping
ASME B 31.4 - Piple line Transportation system for liquid hydrocarbon & Other liquid.
ASME B 31.5 - Refrigeration Piping
ASME B 31.8 - Gas transmission & Distribution piping system.
ASME B 31.9 - Building Services Piping
ASME B 31.11- Slurry Transportation piping system
Q#4: What are the different sections of ASME Code ? Where these sections are reffered?
Ans: ASME Section - I : Rules for construction of Power Boiler
ASME Section - II: Materials: Part ( A) Ferrous Meterials
Part(B) Non - Ferrous Materials
Part (C) Specification for electrodes & Filler wire.
Part (D) Properties
ASME Section - IV: Rules for construction of Heating Boiler
ASME Section - V: Non- Destructive Examination
ASME Section - VI: Recommended ruels for care & operation of heating boiler
ASME Section - VII: Recommended guidelines for care of Power Boiler
ASME Section -VIII: Rules for construction of Pressure Vessels.(Division I & II)
ASME Section - IX : Welding & Brazing qualification
Q#5: Which American Standard is reffered for selection of following piping element?
Answer: Flanges: ASME B 16.1: cast iron pipes flanges and flanged fittings
ASME B 16.5: Carbon steel pipes flanges & Flanged fittings. ( Up to 24 inches)
ASME B 16.47: Large diameter steel flanges ( Above 27")
GasKet:
ASME B 16.20 / API - 601: Metallic gasket sfor pipe flanges - Spiral wound, Octagonal ring Joint & jacketed flanges.
ASME B 16.21: Non Metallic Gasket
Valves:
ASME B 16.10: Face to face and end to end dimension of valves.
Pipes:
ASME B 36.10: Welded & Seamless wrought iron pipe
ASME B 36.19: Stainless steel pipe
Created by: MihirThakur
Checked by: Sanjay Singh
Posted by: ZAMAN
Ans: B 31. 3
Q#2: Which American Institute Standard does Piping Engineer refer?
Ans: API, AISI, ASTM, ANSI, AWS, AWWA, ASME
Q#3: What is the different ASME 31 Code for pressure piping?
Ans: ASME B 31.1 - Power Piping
ASME B 31.2 - Fuel Gas Piping
ASME B 31.3 - Process Piping
ASME B 31.4 - Piple line Transportation system for liquid hydrocarbon & Other liquid.
ASME B 31.5 - Refrigeration Piping
ASME B 31.8 - Gas transmission & Distribution piping system.
ASME B 31.9 - Building Services Piping
ASME B 31.11- Slurry Transportation piping system
Q#4: What are the different sections of ASME Code ? Where these sections are reffered?
Ans: ASME Section - I : Rules for construction of Power Boiler
ASME Section - II: Materials: Part ( A) Ferrous Meterials
Part(B) Non - Ferrous Materials
Part (C) Specification for electrodes & Filler wire.
Part (D) Properties
ASME Section - IV: Rules for construction of Heating Boiler
ASME Section - V: Non- Destructive Examination
ASME Section - VI: Recommended ruels for care & operation of heating boiler
ASME Section - VII: Recommended guidelines for care of Power Boiler
ASME Section -VIII: Rules for construction of Pressure Vessels.(Division I & II)
ASME Section - IX : Welding & Brazing qualification
Q#5: Which American Standard is reffered for selection of following piping element?
Answer: Flanges: ASME B 16.1: cast iron pipes flanges and flanged fittings
ASME B 16.5: Carbon steel pipes flanges & Flanged fittings. ( Up to 24 inches)
ASME B 16.47: Large diameter steel flanges ( Above 27")
GasKet:
ASME B 16.20 / API - 601: Metallic gasket sfor pipe flanges - Spiral wound, Octagonal ring Joint & jacketed flanges.
ASME B 16.21: Non Metallic Gasket
Valves:
ASME B 16.10: Face to face and end to end dimension of valves.
Pipes:
ASME B 36.10: Welded & Seamless wrought iron pipe
ASME B 36.19: Stainless steel pipe
Created by: MihirThakur
Checked by: Sanjay Singh
Posted by: ZAMAN
Some Tips ASME Section -IX
Some Tips ASME SECTION - IX
Question # 1: Why we do perform Tension Test ?
Answer: To check ultimate strength of groove weld joints.
Question#2: Do you know about another test which may be substitute Tension Test?
Answer: Yes, Radio Graphic Test is a substitute test of Tension Test. This test does to prove ability of welder to make sound weld (Groove weld joints)
Question#3: Why do we perform Guided Bend Test?
Answer: To check the degree of soundness and ductility of groove weld joints.
Question # 1: Why we do perform Tension Test ?
Answer: To check ultimate strength of groove weld joints.
Question#2: Do you know about another test which may be substitute Tension Test?
Answer: Yes, Radio Graphic Test is a substitute test of Tension Test. This test does to prove ability of welder to make sound weld (Groove weld joints)
Question#3: Why do we perform Guided Bend Test?
Answer: To check the degree of soundness and ductility of groove weld joints.
Some Important Welding Tips
1) Distance between two grains = grain Boundry
2) Six atoms to eight = One unit
3) Six units to eight = One grain
4) 900c – 1250c for Hardening(Carbon steel, H.S.S. Spring Steel, Dye Steel)
5) 100c – 650c for Tampering
6) 750c – 870c for Normalizing
Heat Treatment Quality Inspection Check
1) No Stress
2) No cavity
3) Fine and close packed grain
4) No Corrosion (surface et c)
5) No oxidation
6) No hydrogen cracks
7) 50% brittle, 50 % Ductile
8) Toughness = 100% strength
9) No Cracks (surface and internal)
10) Cold cracks = Hydrogen cracks
11) Oxygen go to corrosion and silicon go for removing oxygen
12) Steel%0 corrosion = Cu, Si and Co2
13) Blackish brown colour dots shows = Existence of Sulphur and Phosphours in a metal
14) 0.04% = maximum ration of sulphur & Phosphorous
15) Alloy steel: 50:50% brittle & Ductile
16) Impact load = Sudden load
17) Elastic – plastic – breaking point = Tensile load
18) 100% Notch toughness = No stress and 100% strength
19) Stress = Hydrogen
20) Carbon + oxygen – Mono oxide = Blow hole
21) Magnet = Ferrous
22) Non Megnet = Copper , Aluminium, Nickle, and Cobalt
23) Billet & Ingot = Purity ferrous
24) Hot Cracks = Sulphur & Phosphorous
25) Material Impurity cause = 95 % welding defects
26) Boiler Pressure = 150000 pound square inch
27) Boiler Pressure testing = 220000 pound square inch
28) One micro = 5 Years fatigue life
29) Six micros = 2 years fatigue life
30) One Micro ( Fighter Plane Like F-16) = NO FATIGUE LIFE
31) Potassium (K) reduces value of Hydrogen
32) Low Pressure is cause of bursting
COMMON WELDING AND CUTTING PROCESSES
SMAW: Shield Metal Arc Welding
1) Stick welding
2) Manual Metal Welding
3) Consumable metal electrode
4) Capable of welding thin and thick steels and some ferrous metals in all positions
5) High degree of welding skill
GMAW: Gas Metal Arc Welding
1) Mig Welding
2) Co2 welding
3) Micro Arc welding
4) Dip Transfer welding
5) Wire welding
6) Consumable electrode
7) Semi automatically or automatically can be machine operated
8) Thin and thick fairly steels and some nonferrous metals
9) Low degree of welding require
Fusion Process:
1) Gas welding
2) Shield metal arc welding
3) Electro slag welding
4) Thermit welding
5) Submerged Arc welding
6) Inert Gas welding
7) Mag(included Co2) welding
8) Self shielded Arc welding
9) Electron Beam welding
10) Plasma Arc welding
11) Laser Welding
Brazing:
1) Soldering
2) Brazing
Electric Energy:
1) Arc Welding
2) Electro Slag Welding
3) Resistance Welding
4) High Frequency Welding
5) Electron Beam welding
6) Plasma welding
Chemical Energy:
1) Gas Welding
2) Thermit Welding
3) Explosion welding
4) Gas Brazing
Consumable Electrode:
1) Bare Arc ( Metal Arc welding)
2) (Bare stud welding)
3) Stud welding
4) Sheild Metal Arc welding
5) Submerged Arc welding
Shielded Arc:
1) MIG welding
2) MAG (included Co2 welding)
3) Self Shield Arc welding
4) Electrogas welding
5) Inert Gas Arc spot welding
NON COSUMABLE ELECTORDE:
1) Bare Arc( Carbon Arc welding)
Light Energy:
1) Laser welding
2) Light Welding
What is Fabrication?
Application:
1) Light House
2) Deep well
3) Foundation
4) Bridges
5) Mega structures
What is the formula of heating a plate during heat treatment process which is?
Answer: Height is 10 Inches
Width is 12 inches
Height X Width: 10x 12 = 120 X 15 minute/psi = 1800 minutes
1800 divided by 4 = 450 minutes
How can you find inner dia?
Ans: Outer Dia = 6 Inches
Thickness = 10 Inches
Inner Dia : ?
Formula = Outer dia subtract thickness = 5.9 inches inner dia
Some types of Test:
TENSION TEST:
1) Tensile strength kgf/mm2/N/mm2
2) Yield point: Kgf/mm2/N/mm2
3) No 11 and 12 Test : Longitudinal
4) No 5: Transverse Test
5) No 4: Longitdinal and transverse
BEND TEST:
1) Bend Angle 90 Degree
2) Inside Radius ; 6 X Six times
Charpy Impact Test Law:
1) To evaluate notch toughness
2) It break on its centre point
3) 15000/psi pressure( Nuclear vessel)
4) Impact load always applied on weak point
5) Atom’s electron movements slow = Notch toughness less
6) ‘0’ degree centigrade = 60% brittle
7) -5 degree centigrade = 80% brittle (Plain carbon steel)
Posted by: Zaman
2) Six atoms to eight = One unit
3) Six units to eight = One grain
4) 900c – 1250c for Hardening(Carbon steel, H.S.S. Spring Steel, Dye Steel)
5) 100c – 650c for Tampering
6) 750c – 870c for Normalizing
Heat Treatment Quality Inspection Check
1) No Stress
2) No cavity
3) Fine and close packed grain
4) No Corrosion (surface et c)
5) No oxidation
6) No hydrogen cracks
7) 50% brittle, 50 % Ductile
8) Toughness = 100% strength
9) No Cracks (surface and internal)
10) Cold cracks = Hydrogen cracks
11) Oxygen go to corrosion and silicon go for removing oxygen
12) Steel%0 corrosion = Cu, Si and Co2
13) Blackish brown colour dots shows = Existence of Sulphur and Phosphours in a metal
14) 0.04% = maximum ration of sulphur & Phosphorous
15) Alloy steel: 50:50% brittle & Ductile
16) Impact load = Sudden load
17) Elastic – plastic – breaking point = Tensile load
18) 100% Notch toughness = No stress and 100% strength
19) Stress = Hydrogen
20) Carbon + oxygen – Mono oxide = Blow hole
21) Magnet = Ferrous
22) Non Megnet = Copper , Aluminium, Nickle, and Cobalt
23) Billet & Ingot = Purity ferrous
24) Hot Cracks = Sulphur & Phosphorous
25) Material Impurity cause = 95 % welding defects
26) Boiler Pressure = 150000 pound square inch
27) Boiler Pressure testing = 220000 pound square inch
28) One micro = 5 Years fatigue life
29) Six micros = 2 years fatigue life
30) One Micro ( Fighter Plane Like F-16) = NO FATIGUE LIFE
31) Potassium (K) reduces value of Hydrogen
32) Low Pressure is cause of bursting
COMMON WELDING AND CUTTING PROCESSES
SMAW: Shield Metal Arc Welding
1) Stick welding
2) Manual Metal Welding
3) Consumable metal electrode
4) Capable of welding thin and thick steels and some ferrous metals in all positions
5) High degree of welding skill
GMAW: Gas Metal Arc Welding
1) Mig Welding
2) Co2 welding
3) Micro Arc welding
4) Dip Transfer welding
5) Wire welding
6) Consumable electrode
7) Semi automatically or automatically can be machine operated
8) Thin and thick fairly steels and some nonferrous metals
9) Low degree of welding require
Fusion Process:
1) Gas welding
2) Shield metal arc welding
3) Electro slag welding
4) Thermit welding
5) Submerged Arc welding
6) Inert Gas welding
7) Mag(included Co2) welding
8) Self shielded Arc welding
9) Electron Beam welding
10) Plasma Arc welding
11) Laser Welding
Brazing:
1) Soldering
2) Brazing
Electric Energy:
1) Arc Welding
2) Electro Slag Welding
3) Resistance Welding
4) High Frequency Welding
5) Electron Beam welding
6) Plasma welding
Chemical Energy:
1) Gas Welding
2) Thermit Welding
3) Explosion welding
4) Gas Brazing
Consumable Electrode:
1) Bare Arc ( Metal Arc welding)
2) (Bare stud welding)
3) Stud welding
4) Sheild Metal Arc welding
5) Submerged Arc welding
Shielded Arc:
1) MIG welding
2) MAG (included Co2 welding)
3) Self Shield Arc welding
4) Electrogas welding
5) Inert Gas Arc spot welding
NON COSUMABLE ELECTORDE:
1) Bare Arc( Carbon Arc welding)
Light Energy:
1) Laser welding
2) Light Welding
What is Fabrication?
Application:
1) Light House
2) Deep well
3) Foundation
4) Bridges
5) Mega structures
What is the formula of heating a plate during heat treatment process which is?
Answer: Height is 10 Inches
Width is 12 inches
Height X Width: 10x 12 = 120 X 15 minute/psi = 1800 minutes
1800 divided by 4 = 450 minutes
How can you find inner dia?
Ans: Outer Dia = 6 Inches
Thickness = 10 Inches
Inner Dia : ?
Formula = Outer dia subtract thickness = 5.9 inches inner dia
Some types of Test:
TENSION TEST:
1) Tensile strength kgf/mm2/N/mm2
2) Yield point: Kgf/mm2/N/mm2
3) No 11 and 12 Test : Longitudinal
4) No 5: Transverse Test
5) No 4: Longitdinal and transverse
BEND TEST:
1) Bend Angle 90 Degree
2) Inside Radius ; 6 X Six times
Charpy Impact Test Law:
1) To evaluate notch toughness
2) It break on its centre point
3) 15000/psi pressure( Nuclear vessel)
4) Impact load always applied on weak point
5) Atom’s electron movements slow = Notch toughness less
6) ‘0’ degree centigrade = 60% brittle
7) -5 degree centigrade = 80% brittle (Plain carbon steel)
Posted by: Zaman
Duties of a Welding Inspector
Discuss the following
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Posted by: Zaman
Before Welding
1) Safety: Legislation and safe working practices
2) Documentation: Spec. Drawings. Procedures, Welder approvals Certificate, Mill sheets
3) Welding Process and ancillaries: Equipment. Cables, Regulators. Ovens. Quivers. Etc
4) Incoming Consumables: Materials/Welding Consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & Set up: Method . Angels / Root face / Gap Values. Distortion control. Pre heat prior to tack welding if applicable.
During Welding
1) Pre Heating ( Method and control)
2) In Process distortion control (Balance or sequence welding)
3) Consumable control (Correct baking and storage prior to use)
4) Welding process (Related parameters i.e. Volts / Amps.Gas flow rate)
5) Minimum /Maximum inter-pass temperatures
6) Full compliance with all elements given on the WPS
After Welding
1) Visual Inspection
2) Non Destructive Testing
3) Repairs
4) Repair procedures(NDT/Excavation/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments
RESPONSIBILITIES OF A WELDING INSPECTOR
1) To Observe : Activities & Imperfections
2) To Record: Activities & Imperfections
3) To Compare: Activities & Imperfections
Attributes of an effective Welding Inspector
1) Honest
2) Literate
3) Respected
4) Dedicated
5) Impartial
6) Observant
7) Decisive
8) Analytical
9) Knowledgeable
10) Experienced
11) Record Keeping skills
12) Communication Skills
13) Safety conscious
14) Inquisitive
15) Responsible
16) Diplomatic Skills
A Welding Inspectors Toolbox
A welding inspector tool box should contain
A welding Gauge(Cambridge Style, Or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
Any other aids to visual inspection
SPECIALISED AIDS FOR INSPECTION
Inspection may utilize the following specialized equipment:
Boro- scopes (For assessing root runs in small pipes)
Flow-meter (For measuring gas flow rates in MIG/MAG/TIG)
Simple NDT Equipment ( Penetrants and MPI)
Complex NDT equipment (Radiography or Ultrasonics)
NOTE: BOTH simple and complex NDT methods requires the specialized skills of qualified operators/technicians
Posted by: Zaman
Wednesday, January 14, 2009
Gas Welding Temperatures
Gas Welding: Gas welding up to 1800c
Electric Welding 2000c ~ 10000c.
½ “ thick plate 4000c ~ 6000c
6 “ thick plate 9000c ~ 10000c
¼” 2000c ~ 2500c
1/8” 1800c ~2000c
TIG Welding we use
Tungston Inert Gas Welding
1-We use Non consumable tungsten electrode
2-We use Argon as shielding gas
3-We weld only Ca, Al and alloys of Cu & Aluminium
MIG Welding
1-We use consumable electrode using automatic wire feeds.
2-We use MIG welding Machine to weld both Ferrous (Cu, Al and alloys)
3-For welding Al and Cu, we use Argon as shielding Gas.
4-For welding Stainless steel we use Co2 as shielding Gas.
Submerge Arc Welding
SMAW is a five pass welding or multiple pass welding powder. Arc dips into flux. SMAW is a single pass welding. SAW welding powder flux is used properties.
1-Zero defect welding
2-Zero distortion
3-High efficiency
4-Able to weld high volume after work Submarines, Tanks, Ships, Pressure Vessels ( Having Lange thickness)
5-Single pass cutting
What is Earthquake Resistance Steel?
These following qualities should be in steel:-
1-Elongation should be 20%
2-Should be Galvanized ( coating)
3-Should be retain -20c to +20c
Note:- ( 95% defects in welding due to materials)
What is soaking time?
During this period we heated the metal called (soaking time).
What is Radiographic?
Through this we can see all defects, flaws and cracks.
Posted by: Adnan
Electric Welding 2000c ~ 10000c.
½ “ thick plate 4000c ~ 6000c
6 “ thick plate 9000c ~ 10000c
¼” 2000c ~ 2500c
1/8” 1800c ~2000c
TIG Welding we use
Tungston Inert Gas Welding
1-We use Non consumable tungsten electrode
2-We use Argon as shielding gas
3-We weld only Ca, Al and alloys of Cu & Aluminium
MIG Welding
1-We use consumable electrode using automatic wire feeds.
2-We use MIG welding Machine to weld both Ferrous (Cu, Al and alloys)
3-For welding Al and Cu, we use Argon as shielding Gas.
4-For welding Stainless steel we use Co2 as shielding Gas.
Submerge Arc Welding
SMAW is a five pass welding or multiple pass welding powder. Arc dips into flux. SMAW is a single pass welding. SAW welding powder flux is used properties.
1-Zero defect welding
2-Zero distortion
3-High efficiency
4-Able to weld high volume after work Submarines, Tanks, Ships, Pressure Vessels ( Having Lange thickness)
5-Single pass cutting
What is Earthquake Resistance Steel?
These following qualities should be in steel:-
1-Elongation should be 20%
2-Should be Galvanized ( coating)
3-Should be retain -20c to +20c
Note:- ( 95% defects in welding due to materials)
What is soaking time?
During this period we heated the metal called (soaking time).
What is Radiographic?
Through this we can see all defects, flaws and cracks.
Posted by: Adnan
Chalpy Law:-
Chalpy Law:-
Chalpy impact test is done to check if toughness of the metal is same from +40c up to -40c and from + 40 to -40c if metal is tough it will be remain 50% ductile and 50% brittle. Usually metals which are used in fabrication of Air craft and low temperature service application its notch toughness must be same from +40 to -40c. Normally low alloy steel especially Nickle steel has good notch toughness even at -250c to such Nickle steel. Nickle steel with 36% Nickle has good notch toughness even at -300c.
This Nickle is used to make pressure vessel for storage of Hydrogen and Helium having boiling points below -250c . (-350c solidity).
Notch toughness only Alloy steel has good notch toughness where as plain has inferior.
Vanadium: Vanadium makes metal shock metal and also improves notch toughness.
For high temperature: Moly.
Tungsten: Tungsten is added in steel to improve toughness at high temperature like moly.
Ultra high strength steel:
Ultra high strength steel has more than three alloying elements. Like these following mentioned:
V: Vanadium
W:Tungsten
Co: Cobalt
Ni: Nickle
Posted by: Adnan
Chalpy impact test is done to check if toughness of the metal is same from +40c up to -40c and from + 40 to -40c if metal is tough it will be remain 50% ductile and 50% brittle. Usually metals which are used in fabrication of Air craft and low temperature service application its notch toughness must be same from +40 to -40c. Normally low alloy steel especially Nickle steel has good notch toughness even at -250c to such Nickle steel. Nickle steel with 36% Nickle has good notch toughness even at -300c.
This Nickle is used to make pressure vessel for storage of Hydrogen and Helium having boiling points below -250c . (-350c solidity).
Notch toughness only Alloy steel has good notch toughness where as plain has inferior.
Vanadium: Vanadium makes metal shock metal and also improves notch toughness.
For high temperature: Moly.
Tungsten: Tungsten is added in steel to improve toughness at high temperature like moly.
Ultra high strength steel:
Ultra high strength steel has more than three alloying elements. Like these following mentioned:
V: Vanadium
W:Tungsten
Co: Cobalt
Ni: Nickle
Posted by: Adnan
Cold Work Steel
Cold work steel:
Cold work steel is Dye Steel (D1, D2, D3, D4, D5………. Etc.
Carbon = 2% + Vanadium, Tungsten, Nickle, Silicon……. High strength
Cold working (Room Temperature)
Hot work steel:
Hot worked steel is used to make hot working dies for receiving Malten metals for casting.
Hot worked steels series H1, H2, H5, H11, H13, H14 etc.
Carbon = 2%
Moly, Vanadium, Tungsten, Nickle, Silicon
Moly and Tungsten are High temperature.
Hot working (High temperature)
Note: (Greater the Number of alloying elements in steel with 2% carbon higher is the Hardening Temperature / Normalizing temperature).
Posted by: Adnan
Cold work steel is Dye Steel (D1, D2, D3, D4, D5………. Etc.
Carbon = 2% + Vanadium, Tungsten, Nickle, Silicon……. High strength
Cold working (Room Temperature)
Hot work steel:
Hot worked steel is used to make hot working dies for receiving Malten metals for casting.
Hot worked steels series H1, H2, H5, H11, H13, H14 etc.
Carbon = 2%
Moly, Vanadium, Tungsten, Nickle, Silicon
Moly and Tungsten are High temperature.
Hot working (High temperature)
Note: (Greater the Number of alloying elements in steel with 2% carbon higher is the Hardening Temperature / Normalizing temperature).
Posted by: Adnan
Flux Composition
Types of Cracks in Weld:
1.Hydrogen Cracks or Cold Cracks or delayed Cracks.
2.Hot Cracks or Sulphur or Phosphorous Cracks.
Flux Composition:
1: Mn + S Mns ( Slag) Removal of S&P to reduce Hot cracks in weld
2: Mn + P Mnp (Slag)
4.Na + H NaH ( Slag) ( Removal of Hydrogen to reduce Hydrogen Cracks.
5.Ca + H CaH ( Slag)
6.K + H KH
7.Si + O2 SiO2 (Removal of oxygen to reduce stress corrosion cracks in weld.
Posted by: Adnan
1.Hydrogen Cracks or Cold Cracks or delayed Cracks.
2.Hot Cracks or Sulphur or Phosphorous Cracks.
Flux Composition:
1: Mn + S Mns ( Slag) Removal of S&P to reduce Hot cracks in weld
2: Mn + P Mnp (Slag)
4.Na + H NaH ( Slag) ( Removal of Hydrogen to reduce Hydrogen Cracks.
5.Ca + H CaH ( Slag)
6.K + H KH
7.Si + O2 SiO2 (Removal of oxygen to reduce stress corrosion cracks in weld.
Posted by: Adnan
Welding Symbols & Residual Stress
Spot Welding:
V groove :
K groove:
X groove:
II I groove:
Flare:
K flare:
Frange:
Double frange:
Filled Weld:
Weld Bead:
Site welding:
Full circle welding:
Full circle fillet welding:
Flux ingredients take out impurities from molten pool as slag
During welding Residual stress develop in Weld Bead and Heat Affected Zone.
Residual Stress:
It is sum of all the welding stresses types.
1. Stress due to higher heat in put.
2. Stress due to higher coaling rate or rapid coaling of weld after welding.
3. Stress due to impurities and gases which enter molten pool during welding.
What is Molten Pool (when molten pool solidifies after coaling it becomes weld bead).
Posted by: Adnan
V groove :
K groove:
X groove:
II I groove:
Flare:
K flare:
Frange:
Double frange:
Filled Weld:
Weld Bead:
Site welding:
Full circle welding:
Full circle fillet welding:
Flux ingredients take out impurities from molten pool as slag
During welding Residual stress develop in Weld Bead and Heat Affected Zone.
Residual Stress:
It is sum of all the welding stresses types.
1. Stress due to higher heat in put.
2. Stress due to higher coaling rate or rapid coaling of weld after welding.
3. Stress due to impurities and gases which enter molten pool during welding.
What is Molten Pool (when molten pool solidifies after coaling it becomes weld bead).
Posted by: Adnan
Elongation Tensile Load Standard
Elongation Tensile Load Standard
Alloy steel standard before breaking: 15: 20 % (International Standard)
Pakistani steel standard: 11%
This standard has been followed by Pakistan Central Testing Laboratory update as per ASTM standards 1952 not revised with the present needs.
What is the difference between Voltage and Ampere?
Voltage: Voltage is difference of potential to do work between two points.
Current: Current is flow of electrons due to applied voltage. Life safety is to use Low Voltage & high amperage current.
Heat ( Energy) = Power
Power = V x I = VI
100 KVA
Posted by: Adnan
Alloy steel standard before breaking: 15: 20 % (International Standard)
Pakistani steel standard: 11%
This standard has been followed by Pakistan Central Testing Laboratory update as per ASTM standards 1952 not revised with the present needs.
What is the difference between Voltage and Ampere?
Voltage: Voltage is difference of potential to do work between two points.
Current: Current is flow of electrons due to applied voltage. Life safety is to use Low Voltage & high amperage current.
Heat ( Energy) = Power
Power = V x I = VI
100 KVA
Posted by: Adnan
Heat Treatment Techniques
Big cavity will allow oxygen and other gasses to enter and make it brittle. Close grain Good quality and no stress good quality 100% strength.
Close grain or close packed grain is formed due to heat treatment of metal and metal grain become soft.
Open grain: Poor quality high stress, poor ductility and highly brittle.
Over heating and very low temperature makes grain of metal brittle and loss of ductility and strength and boundry between two grains is far apart and cavity size become large.
Posted by: Adnan
Close grain or close packed grain is formed due to heat treatment of metal and metal grain become soft.
Open grain: Poor quality high stress, poor ductility and highly brittle.
Over heating and very low temperature makes grain of metal brittle and loss of ductility and strength and boundry between two grains is far apart and cavity size become large.
Posted by: Adnan
Important Temperature
Some Important temperature
Hardening Temperature Cooling process
Carbon Steel 780 – 850c Cool in Air
High Speed Steel1200 – 1250c Cool in Air
Dye Steel 900 – 1000c Cool in Air
Spring steel 780 – 850c Cool in Air
Tempering Process
Element Temperature Time
Carbon Steel 200 – 220c ½ hours
Dye steel 200 – 400c 1 hour
High speed steel560 – 600c 1.5 hours
Spring steel 300 – 350c 1-3 hours
Annealing Process
High carbon steel830 – 870c 4 hours
High Carbon steel810 – 850c 4 hours
Dye- steel 800 – 850c 4 hours
Spring steel 750 – 800c 4 hours
Normalizing Process
Carbon steel 830 – 880c Cool in air
Spring Steel 760 – 810c Cool in air
Carbon Manganese ( Tool Steel) 800 – 850c Cool in air
Metal Temperature by color
Faint Red 500c
Blood Red 580c
Dark Cherry 635c
Medium Cherry 690c
Cherry 745c
Bright Cherry 790c
Salmon 845c
Dark orange 890c
Orange 940c
Lemon 1000c
Light yellow 1080c
Posted by: Adnan
Hardening Temperature Cooling process
Carbon Steel 780 – 850c Cool in Air
High Speed Steel1200 – 1250c Cool in Air
Dye Steel 900 – 1000c Cool in Air
Spring steel 780 – 850c Cool in Air
Tempering Process
Element Temperature Time
Carbon Steel 200 – 220c ½ hours
Dye steel 200 – 400c 1 hour
High speed steel560 – 600c 1.5 hours
Spring steel 300 – 350c 1-3 hours
Annealing Process
High carbon steel830 – 870c 4 hours
High Carbon steel810 – 850c 4 hours
Dye- steel 800 – 850c 4 hours
Spring steel 750 – 800c 4 hours
Normalizing Process
Carbon steel 830 – 880c Cool in air
Spring Steel 760 – 810c Cool in air
Carbon Manganese ( Tool Steel) 800 – 850c Cool in air
Metal Temperature by color
Faint Red 500c
Blood Red 580c
Dark Cherry 635c
Medium Cherry 690c
Cherry 745c
Bright Cherry 790c
Salmon 845c
Dark orange 890c
Orange 940c
Lemon 1000c
Light yellow 1080c
Posted by: Adnan
Important Temperature
Some Important Boling Points
Element Value/Boiling Point Quantity of Nickle Statement
Butene -0.5 to -5.0c 2.5 % Low carbon steel
Ammonia -33c to -35c 2.5% Al killed steel (It kill bad affects of iron)
Propane -45c 2.5% Low alloy high tensile steel
Propylane -48c 2.5% With 2.5% Nickle addition
Co2 -79c 3.5% 3.5% Nickle
Acetylane -84c 3.5% Nickle
Ethyane -104c 3.5% 3.5% Nickle
Methane -163c 9 % 9 % Nickle
Oxygen -183c 9 % 9 % Nickle
Argon -186c 9 % 9 % Nickle
Nitrogen -196c 9 % 9 % Nickle
Hydrogen -253c 36 % 36 % Nickle
Helium -269c 36 % 36 % Nickle
Posted by : Adnan
Element Value/Boiling Point Quantity of Nickle Statement
Butene -0.5 to -5.0c 2.5 % Low carbon steel
Ammonia -33c to -35c 2.5% Al killed steel (It kill bad affects of iron)
Propane -45c 2.5% Low alloy high tensile steel
Propylane -48c 2.5% With 2.5% Nickle addition
Co2 -79c 3.5% 3.5% Nickle
Acetylane -84c 3.5% Nickle
Ethyane -104c 3.5% 3.5% Nickle
Methane -163c 9 % 9 % Nickle
Oxygen -183c 9 % 9 % Nickle
Argon -186c 9 % 9 % Nickle
Nitrogen -196c 9 % 9 % Nickle
Hydrogen -253c 36 % 36 % Nickle
Helium -269c 36 % 36 % Nickle
Posted by : Adnan
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