What is a thick piece of metal that is used to absorb heat in welding called?

In the context of welding, a chill plate serves the purpose of absorbing excess heat from the weld area, which helps control the thermal gradient and prevent distortion or warping of the base metal. Chill plates are particularly useful in processes like Gas Tungsten Arc Welding (GTAW), where managing heat input is crucial for maintaining material integrity and achieving a high-quality weld.

The use of chill plates helps to draw heat away from the weld puddle, ensuring that the metal cools evenly and reducing the risk of undesirable effects such as cracking or deformations. This technique is often employed when working with thicker materials or when a more controlled cooling rate is desired to enhance the mechanical properties of the weld.

In contrast, other terms mentioned have different roles in welding. A heat sink is typically a component designed to dissipate heat away from sensitive parts; a backing bar is used to provide support for the weld and can influence the join's characteristics but does not necessarily absorb heat; and heat shields are utilized to protect other components or surroundings from heat but do not actively absorb it as effectively as a chill plate.