What can result from inadequate cleaning of the base metals before welding?

Inadequate cleaning of base metals before welding can lead to poor weld quality and a higher likelihood of defects, such as porosity. This occurs because contaminants like dirt, rust, oil, or other foreign materials can introduce impurities into the weld pool. These impurities can hinder the fusion between the base metals, leading to incomplete penetration and resulting in porous, weak areas within the weld. Porosity specifically refers to small gas pockets that form within the weld due to trapped gases escaping from the contaminants during the welding process. This not only compromises the structural integrity of the weld but may also lead to premature failure of the welded joint under stress or fatigue.

Proper cleaning of base metals is essential to ensure a strong bond and achieve the desired mechanical properties in the weld. It helps in promoting a clean weld pool, allowing for proper fusion and minimizing the introduction of defects, ultimately resulting in stronger and more reliable welds.