hardening furnace

Quenching is to quickly cool the workpiece in water, oil or other inorganic salt, organic water solution and other quenching media after heating and holding. After quenching, the steel becomes hard but brittle at the same time. In order to reduce the brittleness of steel parts, the quenched steel parts are kept at a suitable temperature higher than room temperature but lower than 650 ℃ for a long time, and then cooled. This process is called tempering. Tempering is often used in combination with quenching and normalizing.