Question

What is the expansion of PWHT in welding?
1. Postal Weld Horizontal Treatment
2. Post Weld Heat Treatment
3. Pre Weld Heating Torch
4. Post Weld Heating Torch

Answer 1

Correct Answer - Option 2 : Post Weld Heat Treatment

Explanation:

Post Weld Heat Treatment          

• Post weld heat treatment at 580-650°C was originally conceived as a means of relieving residual stress and was indeed known as stress relieving.
• High levels of stress also increase the risk of hydrogen cracking.
• The other beneficial effect of post-weld heat treatment is that it tempers and softens hard transformation products in the Heat Affected Zone, and eliminates strain-age embrittlement.
• It is required for thicker sections of carbon and carbon-manganese steel in structures and pressure vessels.