Which of the following is typically not caused by improper welding?

Lamination is typically not caused by improper welding because it is a defect related to the material itself, often occurring during the manufacturing process of steel or other metals. This defect involves layers of material not being adequately bonded together, resulting in weak points within the material that could lead to failure. In contrast, porosity, cracks, and rollover are all issues that can arise directly from the welding process.

Porosity refers to the formation of tiny holes in the weld due to trapped gas, which can happen if the welding environment is contaminated or if the proper techniques aren’t used. Cracks can occur due to thermal stresses, rapid cooling, or improper welding parameters. Rollover typically describes a situation where the weld metal flows over the edge of the base metal, which can be a direct result of technique or the settings used during welding. Hence, the distinction lies in the fact that lamination is fundamentally a manufacturing defect rather than a consequence of welding practices.