Heat applied before a welding operation is referred to as?

Preheat is the term used to describe the heat applied to the base material before the welding operation begins. This technique is often employed to reduce the risk of cracking, particularly in materials that are sensitive to thermal stress or have a high carbon content.

By preheating the workpieces, the material's temperature is raised, which helps to minimize the temperature differential between the weld bead and the base metal when welding begins. This controlled application of heat allows the filler metal to fuse more readily with the base materials and aids in achieving a good quality weld.

Preheat temperature requirements can vary based on the specific materials being welded, the thickness of those materials, and the welding process to be used. It’s crucial for welders to consult relevant specifications, such as the D1.1 code, to determine the appropriate preheat temperature.

The other terms related to heat treatment have distinct differences. Postheat refers to the application of heat after welding, often for stress relief or to improve mechanical properties. Initial heat generally does not refer to a standard term in welding but may cause confusion as preheat can sometimes be viewed as an initial heating step. Heat treatment encompasses a broader range of processes and usually involves controlled heating and cooling cycles for the purpose of altering material