Cr12模具钢热处理工艺及耐磨性能

Heat treatment process and wear resistant property of Cr12 die steel

通过对Cr12冷作模具钢预处理工艺的改进,将经最佳预处理工艺后的合金进行一次硬化和二次硬化处理,研究了热处理工艺对Cr12钢组织和性能的影响,并分析比较了一次硬化和二次硬化的耐磨性。结果表明:Cr12钢的最佳预处理工艺为等温退火(860℃×120 min+740℃×180 min炉冷至550℃后空冷)加调质处理(500℃×72 min+800℃×36 min+1080℃×18 min油冷+760℃×120 min空冷),该工艺处理后获得的碳化物颗粒细小,分布均匀,硬度适当,且大大缩短了处理周期。二次硬化后的碳化物更加弥散细小且耐磨性更好,碳化物类型主要为(Fe,Cr)C型。

Different pre-treatments of Cr12 cold die steel were carried out and the optimum pre-treatment process was determined based on the experiments. First hardening and secondary hardening experiments of the Cr12 steel treated by the optimum pre-treatment process were also conducted. The effect of heat treatments on microstructure and properties of the Cr12 steel was investigated. The results show that the best pre-treatment process of Cr12 steel are isothermal annealing treatment( 740 ℃ for 180 min after 860 ℃ for 120 min and then air cooling after furnace cooling to about 550 ℃),and quenching and tempering( 500 ℃ for 72 min,800 ℃ for 36 min,oil cooling after 1080 ℃ for18 min and then air cooling after 760 ℃ for 120 min),by which the carbides of the steel are fine and well distributed and the steel exhibits good machineability,and the processing time is shortened greatly. The carbides of the steel after secondary hardening disperse more uniformly and are more finer and the steel has better wear-resistance performance. The main type of the carbides is( Fe,Cr) C.