Maintenance Technician Practice Test

Using peening during welding is a technique that involves the mechanical deformation of the weld area to relieve residual stresses that can lead to cracking. When metal is heated during welding, it expands; as it cools, it contracts. This cooling process can create tensile stresses that may exceed the material's yield strength, leading to the formation of cracks. Peening counteracts these potential issues by impacting the surface of the weld, which compresses the surface layer and alters the stress distribution. This compression helps to mitigate the tensile stresses that would otherwise promote cracking. Therefore, the practice of peening is effective in preventing cracks in welded joints, ensuring the integrity and strength of the weldment. While contaminants, overheating, and discontinuous welds are also important factors to consider in welding processes, peening directly addresses the development of cracks due to residual stress, making it a crucial technique in maintaining the weld's quality.