What is tempering used for in metal treatment?

Tempering is a heat treatment process applied to metals, particularly steel, after they have been hardened. The primary purpose of tempering is to enhance the toughness and ductility of the metal.

When metal is initially hardened, it becomes very strong but also brittle. This brittleness can lead to the risk of cracking or breaking under stress. Through the tempering process, the metal is heated to a specific temperature that is below its critical point and then cooled down. This controlled heating allows for the reduction of internal stresses introduced during hardening. As a result, the microstructure of the metal transforms, which increases its toughness—meaning the ability to absorb energy and deform without fracturing—and also improves ductility, allowing the metal to undergo significant plastic deformation before breaking.

Enhancing toughness and ductility is essential in applications where the metal needs to withstand dynamic loads and avoid sudden failure, making tempering a crucial step in the production of durable metal components.