List two methods of correcting distortion after welding?

1. Post-weld heat treatment: This method involves heating the welded material to a specific temperature and holding it at that temperature for a certain period of time to relieve internal stresses and reduce distortion. This process can help to correct distortion caused by welding.

2. Mechanical straightening: This method involves using mechanical force to straighten or reshape the welded material. This can be done by applying pressure or using hydraulic or mechanical devices to bend or reshape the material back to its original form. This method is often used for correcting distortion in welded structures.

1. Flame straightening
2. Mechanical straightening