气体软氮化对Cr12钢微观组织及摩擦学性能影响  

Effect of Surface Nitriding Treatment on Microstructure and Tribological Properties of Cr12 Die Steel

作　　者：季德惠 张金洲 熊光耀 沈明学 JI De-hui;ZHANG Jin-zhou;XIONG Guang-yao;SHEN Ming-xue(School of Material Science and Engineering,East China Jiaotong University,Jiangxi Nanchang 330013,China;School of Material Science and Engineering,Zhejiang University of Technology,Zhejing Hangzhou 310032,China)

机构地区：[1]华东交通大学材料科学与工程学院,江西南昌330013 [2]浙江工业大学材料科学与工程学院,浙江杭州310032

出　　处：《机械设计与制造》2022年第4期55-58,64,共5页Machinery Design & Manufacture

基　　金：国家自然科学基金(51775503);浙江省自然科学基金(LY17E050020);中国博士后科学基金(2017M620152,2018T110392)。

摘　　要：冷作模具成型压力大、应力状态复杂,在工业生产中常常伴随过度磨损、疲劳失效等问题出现,因此在Cr12模具钢表面进行了软氮化工艺处理基础上,对比分析了有无氮化处理对材料硬度、表面耐磨性的影响,探讨了氮化处理前后表面的摩擦磨损特性。结果表明:氮化处理后Cr12钢出现由白亮层(厚度约3μm)和扩散层(深度达20μm以上)组成的渗氮层,其中白亮层氮元素含量较高,而在扩散层氮元素沿深度方向呈递减分布;Cr12钢氮化前后表面平均维氏硬度由HV_(50)=504.8提高到HV_(50)=653.4,磨损量由42969.6μm^(3)减少到3068.1μm^(3),表明气体软氮化处理对Cr12钢表面硬度与耐磨性能均有显著提高;氮化处理的磨损表面以磨粒磨损为主,而未氮化处理磨损表面的疲劳剥落特征显著,并伴有强烈的氧化磨损现象。Due to high molding pressure and complicated stress state,problems such as excessive wear and fatigue failure often occur in cold work die during the industrial production.Thus,soft nitriding processing was applied to the surface of Cr12 die steel on this basis,the effects of nitriding and non-nitriding treatment on hardness and wear resistance surface of Cr12 die steel samples were investigated and analyzed.The results demonstrate that the nitriding layer consisting of white bright layer(the thickness is about 3μm)and diffusion layer(the depth is more than 20μm)is appeared in the nitrided Cr12 steel,the bright layer has a high nitrogen content,and the content of the nitrogen in the diffusion layer is decreasing along the depth direction.The vickershardness of the Cr12 steel before and after nitriding is improved from HV_(50)=504.8 to HV_(50)=653.4 HV,the abrasion loss is reduced from 42969.6μm^(3) to 3068.1μm^(3).The hardness of the surface and the wear resistance of the Cr12 steel after nitriding is improved significantly.The wear mechanism of nitriding treatment was mainly abrasive wear while the fatigue surface peeling characteristics of the wear surface without nitriding treatment are remarkable,accompanied by strong oxidative wear phenomenon.

关 键 词：软氮化 CR12模具钢 硬度 摩擦磨损 微观组织 磨损机制 

分 类 号：TH16[机械工程—机械制造及自动化] TH117.1