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