What is Distortion in Welding?
Distortion is defined as a change in the shape or size of a welded structure. It can occur during any phase of the welding process, from joint preparation to cooling of the weld metal. Distortion can be caused by a variety of factors, including welding process variables, differences in metal properties, and geometry of the component being welded.
Types of distortion in welding
The most common type of distortion is longitudinal shrinkage, which occurs due to the contraction of the weld metal as it cools. Longitudinal shrinkage typically causes the workpiece to become narrower and/or shorter. Other types of distortion include:
- and twisting.
Welding distortion can often be minimized or eliminated through proper joint design, the use of appropriate welding techniques, and careful control of welding parameters. However, in some cases, it may be necessary to perform post-weld heat treatment (PWHT) to relieve stresses and improve dimensional accuracy.
What causes distortion?
The most common cause of distortion is the contraction of the weld metal as it cools. This is due to the fact that welding heats the metal to such a high temperature that it becomes molten. As the weld metal cools and solidifies, it contracts.
Other causes of distortion include:
- Differences in metal properties.
- The geometry of the component being welded.
- Welding process variables.
How to prevent distortion in welding?
There are a few ways that you can prevent distortion in welding, and they include:
- Proper joint design.
- Use of appropriate welding technique.
- Careful control of welding parameters.
- Post-weld heat treatment (PWHT).