摘要
采用直读光谱仪、数显洛氏硬度计、光学显微镜及扫描电镜,对失效的SLD钢模具的化学成分、表面硬度及显微组织进行检测和分析。结果表明,放置模具变形失效的原因是基体组织中残留奥氏体含量过多,马氏体未能彻底转变。模具在放置过程中,基体中不稳定的残余奥氏体组织继续向马氏体转变,体积发生膨胀,造成模具在放置过程中伸长。其中网状共晶碳化物超标,沿网状共晶碳化物变形方向,尺寸增大。模具回火不充分,组织应力未能消除,在放置过程中继续释放,进一步促使模具变形和伸长,基体组织同时产生应力开裂的显微裂纹。
The chemical composition,surface hardness and microstructure of the failed SLD steel mold were examined and analyzed by direct reading spectrometer,digital Rockwell hardness tester,optical microscope and scanning electron microscope.The results show that the failure reason to place mold is the excessive retained austenite in the matrix and the incomplete transformation of martensite.During the placement of the mold,the unstable retained austenite structure in the matrix continuously transforms to martensite and its volume expands,resulting in the mold to elongate during the placement,in which the eutectic carbides exceeds the standard,and the size increases along the deformation direction of the eutectic carbides.The tempering of the mold is not sufficient,the structural stress can not be eliminated and is continuously released during the placement,which will further promote the deformation and elongation of the mold,and there is microcrack in the matrix structure due to producing stress cracking.
作者
谢俊堂
郭联金
金林奎
陈金生
XIE Jun-tang;GUO Lian-jin;JIN Lin-kui;CHEN Jin-sheng(Guangdong Polytechnik Biomass Energy Company,Jieyang Guangdong515557,China;Department ofElectrical and Mechanical Engineering,Dongguan Polytechnic,Dongguan Guangdong523808,China;National Mold Product Quality Supervision and Inspection Center,Dongguan Guangdong523808,China)
出处
《热处理技术与装备》
2019年第2期9-14,共6页
Heat Treatment Technology and Equipment
基金
广东省东莞市产学研合作项目(201550910500294)
2018年广东省大学生科技创新培育专项基金项目(pdjhb0902)
东莞职业技术学院2017年科研基金重点项目(2017a05)
