What is the primary function of filler metals in welding?

The primary function of filler metals in welding is to provide strength to the weld. During the welding process, filler metals are added to the molten weld pool to help form the joint between the base materials. The filler metal contributes to the overall mechanical properties of the weld, ensuring it can withstand the intended loads and stresses once it has solidified. A strong weld is crucial for structural integrity, and the filler metal plays a significant role in achieving the desired strength.

While options related to reducing hardening, preventing corrosion, and increasing melting point may have their individual merits or applications, they do not represent the fundamental purpose of filler metals in the welding process. Instead, the emphasis is on how the filler metal enhances the welded joint's load-bearing capacity, making it the key aspect in identifying its primary function.