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对Cr12冷作模具钢分别进行了不同温度的淬火及回火,研究了淬火及回火温度对模具钢组织及力学性能的影响。结果表明:在淬火态,钢的基体为片状马氏体与残留奥氏体混合组织。淬火后回火,片状马氏体消失,随着回火温度的升高,基体由粗大的片状马氏体逐渐转变为细小的板条状回火马氏体,力学性能提高,断口中的断裂韧窝增多。当淬火为1000℃,回火为550℃时,基体由细小的板条状回火马氏体与粒状回火索氏体混合组织组成,屈服强度为750 MPa,抗拉强度为1050 MPa,断后伸长率为13.6%,冲击功为63 J,此时模具钢的综合力学性能最优。
The cold working die steel of Cr12 was quenched and tempered at different temperatures respectively. The effects of quenching and tempering temperature on the microstructure and mechanical properties of die steel were studied. The results show that in the quenched state, the matrix of the steel is a mixture of lamellar martensite and retained austenite. After quenching and tempering, the sheet-like martensite disappears. With the increase of tempering temperature, the matrix gradually changes from coarse lamellar martensite to fine lath-shaped tempered martensite, and its mechanical properties are improved. In the fracture Of the fracture dimples increased. When the quenching temperature is 1000 ℃ and the tempering temperature is 550 ℃, the matrix is composed of fine lath tempered martensite and granular tempered sorbite. The yield strength is 750 MPa, the tensile strength is 1050 MPa, Elongation rate of 13.6%, impact energy of 63 J, the best comprehensive mechanical properties of die steel.