4. In Case Of Welded Vessels Why Is Stress Relieving In The Form Of Post-weld Treatment Necessary?
When a metal is welded together the point at which the two surfaces are joined are subjected to very high temperatures. During this time period the metals can go through a lot of random metallurgical processes. This causes the metal to be harder and brittle. This depends on the amount of carbon content. In order to relieve the metal of these properties heat treatment is done on the affected areas. By doing so the affected areas ductility increases. In this process the heat is maintained in the affected metal according to the thickness of the metal. The temperature of the heat is calculated from the P number which is unique for a particular composition.
