Red Seal Metal Fabricator (Fitter) Practice Exam

Which welding issue can be caused by excessive heat input?

1. Poor penetration

2. Increased spatter

3. Weld cracking

4. All of the above

The correct answer is: Weld cracking

Excessive heat input during welding can significantly influence the quality and integrity of the weld. When too much heat is applied, it can lead to metallurgical changes in the base materials, which may result in weld cracking. This is especially true when heat-affected zones experience rapid cooling, leading to stresses that exceed the material's capabilities, causing it to crack. While poor penetration and increased spatter can also arise from excessive heat input, the primary issue directly associated with overheating is weld cracking. It often manifests due to thermal stresses and the potential for the formation of hard, brittle microstructures in certain materials. This understanding is critical for ensuring the longevity and reliability of welded structures.