What is a common defect caused by improper welding techniques?

• A. Sparkling
• B. Excessive spatter
• C. Undercutting
• D. Uniform bead appearance

Answer: (C)

Undercutting is a common defect that arises from improper welding techniques. It occurs when the base metal is melted away at the edge of the weld bead, creating a groove or depression alongside the weld. This can compromise the integrity and strength of the joint, as it reduces the cross-sectional area and may lead to stress concentrations. Factors that contribute to undercutting include incorrect settings on the welding equipment, inadequate travel speed, or improper angles during the welding process.

The presence of undercutting can be detrimental to the performance of the welded structure, especially in applications where the welds must bear significant loads or resist fatigue. Recognizing this defect highlights the importance of proper technique and careful control over the welding parameters to ensure a strong and effective bond between the materials being joined.