In GMAW, what is usually increased due to the addition of hydrogen?

In Gas Metal Arc Welding (GMAW), the addition of hydrogen to the shielding gas mixture is known to increase the heat level during the welding process. When hydrogen is introduced, it enhances the thermal conductivity of the arc, which results in a more concentrated heat input. This increased heat level allows for better fusion of the base metals and can help in achieving deeper penetration and improved weld quality.

The added heat can minimize the risk of defects such as lack of fusion and improve the overall performance of the weld. It's important to note that while increased heat can be beneficial, it also requires careful control to avoid overheating or distortion of the workpieces being welded.

In contrast, factors such as weld speed, electrode life, and cooling time are influenced differently by altering gas compositions. Weld speed might not necessarily increase due to higher heat, while electrode life could potentially decrease due to more intense heat exposure. Cooling time might also be affected but not in a direct relationship with hydrogen addition alone. Thus, the primary effect of adding hydrogen in the context of GMAW relates directly to the increase in heat level.