What is the function of the filler material in welding?

The role of filler material in welding is primarily to provide additional material that contributes to the strength and integrity of the weld joint. When two pieces of metal are welded together, the base metals may not have sufficient coverage of material to form a strong bond on their own. Filler material is added to fill any gaps and ensure that the weld joint can withstand the stresses and forces it will encounter in service.

Using filler material allows for a seamless connection between the base materials, achieving a weld that meets or exceeds the strength requirements of the application. This is especially vital in pipelines and other critical infrastructure where weld integrity is essential for safety and performance.

While options such as speeding up the welding process, reducing heat distortion, and enhancing corrosion resistance might be relevant in specific contexts or with certain techniques, they do not directly address the primary function of filler material in contributing structural integrity to the weld joint. Thus, knowing the importance of filler material as a strengthening component is key to understanding its critical role in welding practices outlined in industry standards like API 1104.