Why Do Steel Parts Need To Be Quenched And Tempered? What Is The Effect?

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 °C. Quenching and tempering can adjust the properties and materials of steel to a great extent. Its strength, plasticity and toughness are all good, and it has good comprehensive mechanical properties.

Quenched and tempered steel has two categories: 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 the quenched and tempered parts, the carbon content is generally controlled at 0.30~0.50%.

During quenching and tempering, the entire section of the workpiece is required to be quenched, so that the workpiece can obtain a microstructure dominated by fine needle-like quenched Martensite. Through high temperature tempering, a microstructure dominated by uniformly tempered Sorbite is obtained. It is impossible for small factories to rely on microstructure analysis for each furnace. Generally, only hardness test is performed. That is to say, the hardness after quenching must reach the quenching hardness of the material, and the hardness after tempering is checked according to the requirements of the drawing.