An undercut is a type of defect that occurs during welding when the base metal is not properly fused or melted, resulting in a groove or depression along the weld joint.
An undercut can be caused by a variety of factors such as improper welding technique, excessive heat or current, insufficient shielding gas, or improper preparation of the weld joint.
An undercut can be detected by visually inspecting the weld joint for any visible grooves or depressions, or by using non-destructive testing methods such as ultrasonic or radiographic testing.
Identifying undercuts is important because they can weaken the structural integrity of the weld joint and lead to failure. They can also compromise the appearance of the weld, which may be important for aesthetic or functional purposes.
To prevent undercuts, it is important to follow proper welding techniques, use the correct heat and current settings, ensure proper shielding gas flow, and properly prepare the weld joint before welding. Regular inspections and quality control measures can also help to prevent undercuts.