What component is crucial for melting the joint faces and filler metal in electroslag welding?

In electroslag welding, the crucial component for melting the joint faces and filler metal is molten slag. This process involves a layer of molten slag that forms between the workpieces to be welded. The slag acts as a medium through which electrical resistance is generated when a current is passed through it. The heat resulting from this resistance melts both the filler material and the base metal at the joint faces.

The molten slag not only helps in achieving the necessary temperatures for melting but also provides a protective cover over the weld pool, preventing contamination from the atmosphere. This creates the conditions for effective fusion and contributes to the overall quality of the weld. In summary, molten slag is essential as it plays a vital role in the electroslag welding process by enabling the necessary melting and protection for the welding operation.