40Cr steel, after quenching and tempering
treatment, has good comprehensive mechanical properties, good low-temperature
impact toughness, and low notch sensitivity. The hardenability of steel is
good, it can be quenched to 28-60mm in water and 15-40mm in oil. This type of
steel is suitable for cyanide and high-frequency quenching treatment in
addition to quenching and tempering treatment. The cutting performance is good,
with a relative machinability of 60% when the hardness is between 174-229HB.
This steel is suitable for making medium-sized plastic molds.
42CrMo steel belongs to ultra-high strength
steel, which has high strength and toughness, good hardenability, no obvious
tempering brittleness, high fatigue limit and resistance to multiple impacts
after quenching and tempering treatment, and good low-temperature impact
toughness. 42CrMo steel is suitable for manufacturing large and medium-sized
plastic molds that require certain strength and toughness.
