What is a heat sink used for in welding?

What is a heat sink used for in welding?

• A. To add heat to the weld to promote deeper penetration.
• B. To remove slag from the weld bead.
• C. To clean up weld smoke.
• D. To absorb heat near the weld, reducing heating rate and controlling distortion.

Answer: (D)

A heat sink in welding is a piece of metal placed near the weld to absorb heat away from the joint. By drawing heat out, it lowers the local heating rate and the amount of heat actually entering the surrounding base metal. That keeps the area cooler, which reduces thermal gradients, helps control distortion and residual stresses, and is especially helpful on thin sections or when multiple passes are needed. It doesn’t add heat, and it isn’t used to remove slag or clean smoke—the purpose is to remove heat and keep the weld area from overheating. Copper blocks or other high‑conductivity materials are common choices for this effect.

A heat sink in welding is a piece of metal placed near the weld to absorb heat away from the joint. By drawing heat out, it lowers the local heating rate and the amount of heat actually entering the surrounding base metal. That keeps the area cooler, which reduces thermal gradients, helps control distortion and residual stresses, and is especially helpful on thin sections or when multiple passes are needed. It doesn’t add heat, and it isn’t used to remove slag or clean smoke—the purpose is to remove heat and keep the weld area from overheating. Copper blocks or other high‑conductivity materials are common choices for this effect.