What are the precautions after quenching of hot rolled steel plate?

Hot rolled steel plate is a high-quality carbon structural steel, which belongs to medium carbon steel. It can be quenched. Its strength and hardness are high after heat treatment. Therefore, it is suitable for making mechanical parts, and it is used in occasions requiring high stress and good wear resistance. Then, after quenching treatment, which aspects should be paid attention to? Let's understand it together!

After quenching, it needs high temperature tempering, the heating temperature is usually 560 ~ 600 ℃, and the hardness requirement is hrc22 ~ 34. Because the purpose of quenching and tempering is to obtain comprehensive mechanical properties, so the hardness range is relatively wide. However, if the drawings have hardness requirements, the tempering temperature should be adjusted according to the drawing requirements to ensure the hardness.

For example, some shaft parts require high strength and high hardness, while some gears and shaft parts with keyway require lower hardness due to milling and inserting after quenching and tempering. As for the tempering holding time, it depends on the hardness requirements and the size of the workpiece.

We believe that the hardness after tempering depends on the tempering temperature and has little relationship with tempering time, but it must be penetrated back. Generally, the tempering holding time of workpieces is more than one hour.