耐冲击工具钢5Cr8MoVSi热处理过程中组织结构的变化  

A study on structure transformation of heat-treatment for the steel 5Cr8MoVSi

作　　者：戴玉梅[1] 刘艳侠[1] 马永庆[1] 张占平[1] 史雅琴[1] 刘莎[1] 

机构地区：[1]大连海事大学船机修造工程实验室,辽宁大连116026

出　　处：《大连海事大学学报》2003年第3期13-17,共5页Journal of Dalian Maritime University

摘　　要：对5Cr8MoVSi钢热处理工艺研究表明,经840℃退火,碳化物类型以M23C6为主,并有少量的MC和M7C3.淬火组织中剩余碳化物以MC和M7C3为主,M23C6型碳化物在淬火加热时大部分溶解.该钢随淬火加热温度升高,淬火马氏体由板条状和针状马氏体混合组织过渡到以板条状马氏体为主.在沉淀硬化的回火温度(485℃)下,淬火针状马氏体仍显示出原马氏体针;而淬火板条状马氏体的板条状方向性几乎被完全切断,显微组织呈均匀化.该钢在1000～1050℃淬火时,残余奥氏体量为10.7%～12.3%,经485℃一次回火时,残余奥氏体量减少不大,因此,应进行二次或三次回火.淬回火HRC硬度最高为58～60.The study of the heattreatment process for steel 5Cr8MoVSi showed that the carbides is composed of primary M23C6.and minor MC and M7C3 after annealed at 840 ℃. The carbides consists of MC, M7C3.and a very few M23C6 in the structure quenched. The lath martensites augment with the quenching temperature. At tempering temperature (485 ℃)of deposition hardening, the microstructure still shows martensites needle. However, lath orientation of martensites quenched is mostly cut off, and the microstructure becomes more unified. The fraction of the retained austenite is about 10.7%～12.3% when the sample was quenched at 1 000～1 050 ℃. The quantity of retained austenite does not evidently decrease by one tempering. Therefore, the steel should be tempered by multitempering to obtain the suitable properties. The hardness after tritempering can be up to HRC 58～60.

关 键 词：耐冲击工具钢 5Cr8MoVSi钢 热处理工艺 组织结构 马氏体形态 

分 类 号：TG142.45[一般工业技术—材料科学与工程] TG161[金属学及工艺—金属材料]