Which of the following is a potential consequence of improper cleaning of joint surfaces before welding?

Improper cleaning of joint surfaces before welding can lead to the formation of defects such as porosity. Porosity occurs when gas is trapped in the weld metal during the solidification process, which can significantly weaken the weld. Contaminants such as oil, grease, rust, or mill scale can prevent the filler material from bonding properly with the base metal. When these impurities are present, they can evolve into gas during the welding process, leading to hollow pockets or voids in the weld, which compromise its integrity and load-bearing capacity. Proper cleaning ensures that the surfaces are free of contaminants, allowing for a strong and effective weld.