What is referred to as heat applied before a welding operation?

The term that refers to heat applied before a welding operation is preheat. Preheating a material is an important step in the welding process as it helps to reduce thermal gradients, prevents the rapid cooling of the weld area, and decreases the risk of cold cracking in certain materials, particularly high-strength steels or those susceptible to hydrogen-assisted cracking.

The preheating process also enhances weldability, allowing for better penetration and fusion during the welding operation. By raising the temperature of the base metal before welding, the stresses that arise from welding are more evenly distributed, which can significantly improve the quality and durability of the weld joint. Understanding the role of preheating in welding procedures is crucial for achieving optimal results and ensuring structural integrity in weldments.