In order to reduce the brittleness of steel, tempering in heat treatment of forgings is to keep the steel at a suitable temperature above room temperature and below 710℃ for a long time and then cool it. This process is called tempering.

The role of tempering

1. Reduce internal stress and brittleness. Quenched parts have great internal stress and brittleness. If they are not tempered in time, they will often deform or even crack.

2. Adjust the mechanical properties of the workpiece. After quenching, the workpiece has higher hardness and greater brittleness. In order to meet the different performance requirements of various workpieces, the hardness, strength, plasticity and toughness of the workpiece can be adjusted by tempering.

3. Stabilize the size of the workpiece. Through tempering, the metallographic structure can be stabilized to ensure that no deformation will occur during future use.

4. Improve the cutting performance of certain alloy steels.