三种渗碳淬火钢对内氧化敏感性研究

Research on Susceptibility of Three Kinds of Steel to Inner Oxidation During Carburizing and Hardening

对17CrNiMo6、18CrNiMo7-6和12Cr2Ni4三种钢在不同渗碳、淬火工艺过程中产生内氧化的敏感性进行了试验研究。采用金相法评定了内氧化的级别。结果表明,三种钢的抗内氧化性能由好到差的顺序为17CrNiMo6钢、12Cr2Ni4钢和18CrNiMo7-6钢;这些钢采用调质作为预备热处理比采用正火、回火作为预备热处理的抗内氧化性能好。此外,17CrNiMo6钢和18CrNiMo7-6钢是渗碳后二次淬火的抗内氧化性能好,而12Cr2Ni4钢是渗碳后一次淬火的抗内氧化性能好。

It has been experimentally investigated whether three kinds of steel such as 17CrNiMo6,18CrNiMo7-6,and 12Cr2Ni4 steels are easy to produce inner oxidation in the course of different carburizing and then hardening processes.The grades of the inner oxidation were evaluated by a metallographic examination.The results show that so far as the resistance to inner oxidation concerned,17CrNiMo6 steel is the best,and 18CrNiMo7-6 steel is the worst of the three steels,and that the three steels previously hardened and high tempered were less susceptive to inner oxidation than ones previously normalized and tempered.In addition,both the 17CrNiMo6 and 18CrNiMo7-6steels exhibited better resistance to inner oxidation during carburizing and double quenching,whereas the 12Cr2Ni4 steel exhibited better resistance to inner oxidation during carburizing and single quenching.