高镜面塑料模具钢Cr4Ni3MnCuAl热处理工艺的研究

Study on Heat Treatment of High Mirror Plastic Mold Steel Cr4Ni3MnCuAl

采用OM、SEM、硬度测试分析方法,研究了不同固溶温度、冷却方式和不同时效温度对Cr4Ni3MnCuAl钢组织和硬度的影响。结果表明:随着固溶温度的升高,固溶硬度呈现先升高后降低的趋势,固溶油冷硬度高于固溶空冷硬度约1.1HRC。固溶冷却后的组织以板条马氏体为主,880尤为最佳的固溶温度。在200℃-610℃范围内时效4h,时效硬度呈现出先升高后降低的趋势。时效4 h可为钢材提供约6.2HRC的硬度增量。520℃时效后得到的组织为板条马氏体+少量粒状贝氏体+少量残余奥氏体。从组织和硬度方面综合评价,880℃固溶油冷+520℃时效为Cr4Ni3MnCuAl钢的最佳热处理工艺。

By using OM,SEM hardness test and analysis,the effect of different solution temperatures,cooling types and aging temperatures on microstructure and hardness of Cr4Ni3MnCuAl steel is studied in this paper.The results indicate that with the increasing of solution temperature,the solution hardness increases first but then decreases.The hardness of oil cooling is about 1.1 HRC higher than that of air cooling.The microstmcture is mainly lath martensite after the solution cooling,of which 880^1 is the best solution temperature.The steel is aged for 4 h from 200℃ to 610℃,with the aging hardness increased first but then decreased.Aging 4 hours provided approximately 6.2HRC hardness increment for steel.The microstructure is lath martensite+a small amount of granular bainite+a small amount of residual austenite.From the comprehensive evaluation of microstmcture and hardness,the oil cooling of solution at 880℃+aging at 520℃ is the optimum process for Cr4Ni3MnCuAl steel.