The microstructure and hardness of precipitated hardening die steel 0Cr3Ni3MoCuAl with solution-treated at 860~1010 ℃ for 35 min and aging treated at 450~560 ℃ for 3 h are tested and studied.The results show that when the solution treatment temperature is 950 ℃
the holding time is 35 min and air cooling to room temperature
the HRC hardness number is up to 39.5
the structure is granular bainite and low carbon lath martensite and a small amount of residual austenite.When the aging-treated at 500 ℃ for the holding time 3 h and air cooling to room temperature
the HRC hardness number is up to 44.1 and the microstructure is tempered bainite.