热处理工艺对塑料模具钢10Ni2Cr2MnCuMoVAl组织和性能的影响

Effect of heat treatment on microstructure and mechanical properties of plastic mold steel 10Ni2Cr2MnCuMoVAl

研究了固溶温度、时效温度及时间对10Ni2Cr2MnCuMoVAl塑料模具钢热处理后的微观组织和力学性能的影响。结果表明：固溶处理后,10Ni2Cr2MnCuMoVAl钢的组织主要是板条马氏体构成,且随固溶温度的升高,马氏体板条发生明显宽化,并在890℃固溶后达到硬度最高值。时效处理后的组织由板条马氏体、粒状贝氏体和析出碳化物构成。当时效温度区间为460～520℃,随着时效温度的升高,材料的强度逐渐升高,韧性逐渐降低,并在520℃达到强度峰值;时效温度高于520℃时,随着温度升高,材料硬度降低,冲击韧性升高。分析在540℃不同时效时间处理后的性能可知,试验钢在8h达到力学性能峰值。通过比较试验钢在不同时效处理后的力学性能数据,10Ni2Cr2MnCuMoVAl钢的最佳热处理工艺为：880℃固溶处理2h＋空冷,随后在520℃时效处理4h＋空冷。

The effects of solution and aging treatment on microstructure and mechanical properties of 10Ni2Cr2MnCuMoVAl plastic mold steel were experimentally studied. The results show that the dominant microstructure of 10Ni2Cr2MnCuMoVAl steel after solid solution treatment is lath martensite,and higher solution temperature results to larger width of martensite,while the highest value of hardness could be obtained after solution treatment at 890 ℃. After aging,the microstructure consists of lath martensite,granular bainite and carbides. For steel aged at 460-520 ℃,the strength of the material gradually increased with higher aging temperature,while the toughness decreased gradually.When the temperature exceeded 520 ℃,higher temperature led to decreased hardness and increased toughness. Compared the mechanical properties of steel aged at 540 ℃ for different time,the test steel reached the peak of mechanical properties at 8 h. By comparing the mechanical properties of the test steels after different aging treatments,the optimized heat treatment process of 10Ni2Cr2MnCuMoVAl steel is solution treatment at 880 ℃ for 2 h with air cooling and tempering temperature at 540 ℃ for 4 h with air cooling.