Thermal residual stress

Internal stress in a component caused by uneven heating or cooling. It forms when adjacent zones expand or contract to varying degrees.

When you weld, you only heat a small area. It wants to expand, but the cold material around it pushes back. When cooling, the weld seam contracts again, and the cold material doesn't allow that. The result is residual stresses in the part.

MetallurgieSchweißtechnik