Postweld heat treatment

Post weld heat treatment is to improve the organization and properties of welded joints or eliminate residual stress and heat treatment carried out. Commonly used methods are normalized or normalized and tempered with two stress elimination process.

a. normalized or normalized and tempered large seam thickness member common ESW completed weld coarse grains, normalizing treatment after welding in order to refine the grain. For thick-walled pressure parts, after normalizing results in a higher internal stress, therefore add tempering to eliminate stress.

b. stress relieving stress generated by the welding work may be superimposed with stress reduces the carrying capacity of the joint. Especially in thick-walled containers and at low temperatures or corrosive conditions of work, the welding joints may cause stress in complex three-stress state, greatly reducing the ability of the joint anti-brittle fracture. Also eliminate the stress treatment improves weld and heat affected zone in the low alloy steel joint, so that rigid organizations have been tempered to improve organizational toughness carbide weld and heat affected zone in the heat-resistant steel weldment manipulation stability, improved high temperature creep rupture strength. Prompting weld metal hydrogen diffusion escape completely, improve weld crack resistance and toughness.