Quenching and tempering treatment: the heat treatment method of high temperature tempering after quenching is called quenching and tempering treatment. High temperature tempering refers to tempering between 500-650 ℃. Quenching and tempering can greatly adjust the properties and materials of steel, with good strength, plasticity and toughness, and good comprehensive mechanical properties.
Quenched and tempered steel includes carbon quenched and tempered steel and alloy quenched and tempered steel. Whether it is carbon steel or alloy steel, its carbon content is strictly controlled. If the carbon content is too high, the strength of the workpiece after quenching and tempering is high, but the toughness is not enough. If the carbon content is too low, the toughness is improved and the strength is insufficient. In order to obtain good comprehensive performance of quenched and tempered parts, the carbon content is generally controlled at 0.30 ~ 0.50%.