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