摘要
该文通过扫描电子显微镜(SEM)、电子背散射衍射(EBSD)组织表征结合显微硬度、拉伸性能实验,系统研究了回火工艺对40CrNiMo钢组织与性能的影响。结果表明:随回火温度升高和回火时间延长,40CrNiMo钢显微硬度、强度降低,均匀延伸率略有增高。随回火温度升高,渗碳体加快析出并逐渐聚集球化,由薄片状向粗粒状转变,而铁素体发生回复和再结晶,逐渐多边形化,使得显微组织由回火屈氏体向回火索氏体转变。450℃回火2 h条件下,40CrNiMo钢的力学性能最佳,其组织由回火屈氏体和回火索氏体构成,屈服强度、抗拉强度分别是1180 MPa和1310 MPa,均匀延伸率和总延伸率分别是4.5%和15%。
Effects of tempering treatments on microstructural evolution and mechanical properties of 40CrNiMo steel are studied via scanning electron microscope(SEM)and electron backscatter diffraction(EBSD)combined with microhardness and tensile tests.Results show that microhardness and strength decrease with the increase of tempering temperature and holding time,while the elongation increases slightly.As tempering temperatures increasing,the formation and spheroidization of cementite precipitation are accelerated,and the morphology gradually changes from film-like to coarse granular,meanwhile,polygonal ferrite gradually appears due to recovery and recrystallization.It caused the microstructure constituents transforms from tempered troostite to tempered sorbite.The best combination of strength and ductility can be achieved after tempering at 450℃for 2 h,the corresponding microstructure is composed of tempered troostite and tempered sorbite.The yield strength and tensile strength reach 1180 MPa and 1310 MPa respectively,and the uniform elongation and total elongation are 4.5%and 15%respectively.
作者
王浩楠
闫晋文
李顺强
刘吉梓
Wang Haonan;Yan Jinwen;Li Shunqiang;Liu Jizi(School of Materials Science and Engineering,Nanjing University of Scienceand Technology,Nanjing 210094,China)
出处
《南京理工大学学报》
CAS
CSCD
北大核心
2022年第3期367-372,共6页
Journal of Nanjing University of Science and Technology
基金
江苏省自然科学基金(BK20201308)
中央高校基本科研业务费专项资金(30918011341)。
