How is 45 round steel quenched and tempered?

The high temperature tempering of 45 round steel after quenching and tempering, the heating temperature is usually 560~600℃, and the hardness is HRC22~34. Because the purpose of quenching and tempering is to obtain comprehensive mechanical properties, the hardness range is relatively wide. However, if the drawings have hardness requirements, the tempering temperature must be adjusted according to the requirements of the drawings to ensure the hardness. For example, some shaft parts require high strength and high hardness; while some gears and shaft parts with key grooves need to be milled and inserted after quenching and tempering, so the hardness requirements are lower.