The hardenability and uses of 40Cr steel

40Cr steel is one of the most widely used steels in the machinery industry. After quenching and tempering treatment, it has excellent comprehensive mechanical properties, excellent low temperature impact toughness and low notch sensitivity.

The hardenability of 40Cr steel is excellent, it can be hardened to Ф28-60mm when water quenched, and can be hardened to Ф15-40mm when oil quenched. In addition to quenching and tempering treatment, 40Cr steel is also suitable for cyanidation and high-frequency quenching treatment. The cutting performance is good. When the hardness is 174-229HB, the relative machinability is 60%. 40Cr steel is suitable for making medium-sized plastic molds.

After quenching and tempering, 40Cr steel is used to make mechanical parts that accept medium load and medium speed operations, such as steering knuckles of cars, rear half shafts and gears, shafts, worms, spline shafts, top sleeves, etc. on machine tools; after quenching and tempering at medium temperature, it is used to make parts that accept high load, impact and medium speed operations, such as gears, spindles, oil pump rotors, sliders, collars, etc.