CAJ | 학술논문

通过金相显微镜、扫描电镜和维氏硬度计，对 P20塑料模具钢进行了显微组织观察和硬度测定，研究了在淬火温度、淬火介质、回火温度等不同预硬化热处理工艺参数条件下得到的组织及其硬度变化规律。结果表明：随着回火温度升高，水淬和空淬钢组织中的板条马氏体和贝氏体逐渐减少，铁素体增加并长大，碳化物增多，硬度逐渐降低，板条间的薄片状 M/ A 组元、铁素体中较高的位错密度以及细小碳化物保证了水淬钢在620℃回火时具有较高的硬度，最终确定了保证该钢种最佳预硬化效果的工艺参数。
통과금상현미경、소묘전경화유씨경도계，대 P20소료모구강진행료현미조직관찰화경도측정，연구료재쉬화온도、쉬화개질、회화온도등불동예경화열처리공예삼수조건하득도적조직급기경도변화규률。결과표명：수착회화온도승고，수쉬화공쉬강조직중적판조마씨체화패씨체축점감소，철소체증가병장대，탄화물증다，경도축점강저，판조간적박편상 M/ A 조원、철소체중교고적위착밀도이급세소탄화물보증료수쉬강재620℃회화시구유교고적경도，최종학정료보증해강충최가예경화효과적공예삼수。
The paper describes the microstructure observation and hardness determination by using optical micro-scope,scanning electron microscope and Vickers hardness tester,studies the changing law of microstructure and hard-ness obtained under the conditions of different pre - hardening heat treatment process parameters such as quenching temperature,quenching medium,tempering temperature. The results show that lath martensite and bainite in the micro-structure of water quenched and air quenched steel gradually decrease with the increase of tempering temperature,fer-rite gradually increases and grows up,the carbide increases and hardness gradually decreases;the flake type M/ A con-stituent between laths,higher displacement density and fine carbide in ferrite attains a relatively higher hardness as the water quenched steel tempered in 620 ℃,and the process parameters ensuring an optimum prehardening result of the steel grade is determined.