摘要
研究了国产P20钢的预硬化热处理制度和表面化学热处理对硬度分布和抛光性能的影响。结果表明,作为大型模具用料时,P20钢预硬化热处理制度为:830～860℃加热淬火,620℃×4h回火,此时30～36HRC。加热、回火温度应力求均匀,保证模具表面硬度差异不致于过大,这对提高研磨质量,降低表面粗糙度是十分重要的。随着回火温度升高,碳化物聚集增加,马氏体溶断,硬度值明显下降,所以,P20钢回火温度应有一个上限。硬度高,虽然难以研磨,但表面粗糙度值小,较易达到或接近镜面要求。为了提高模具对塑料的耐磨性,可采用常规的渗碳、渗氮工艺,在钢表层形成优良的耐磨渗层,表面较容易经抛光而达到镜面光洁度。
The effect of prehardening heat treatment and thermochemical treatment on the case hardness and polishing property of P2O plastics mold steel were studied. The results showed that to obtain suitable hardness range for abrading and polishing, the better prehardening process is austenitizing at 830-860℃ and oil quenching, then tempering at 620℃ for 4 hours, the hardness is about 30-36HRC. If the tempering temperature is higher than 620℃ the hardness of the steel will decrease evidently because of carbides Coarsing and martensite dissociating. The good abrasion resistance case will be formed by carburzing or nitriding, thereby the mirror surface finish could be obtained easily by polishing and the service life of the mold may be prolonged considerably.
出处
《金属热处理》
CAS
CSCD
北大核心
1991年第11期32-37,46,共7页
Heat Treatment of Metals
