AISI304奥氏体不锈钢阳极渗氮层的组织与摩擦磨损性能  

Tribological properties and structure of anodic nitrided layer on AISI 304 austenitic stainless steel

作　　者：李杨[1,2] 何永勇[1] 张尚洲[2] 张磊[2] 赵军[1] LI Yang HE Yong-yong ZHANG Shang-zhou ZHANG Lei ZHAO Jun(State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China Department of Materials Science and Engineering, Yantai University, Yantai 264005, China)

机构地区：[1]清华大学摩擦学国家重点实验室,北京100084 [2]烟台大学环境与材料工程学院,山东烟台264005

出　　处：《材料热处理学报》2017年第2期152-157,共6页Transactions of Materials and Heat Treatment

基　　金：国家重点基础研究发展规划项目("973")(2014CB046404);国家自然科学基金(51301149);中国博士后基金(2015M570090)

摘　　要：为避免传统直流离子渗氮存在的表面打弧和边缘效应等弊端,采用活性屏阳极渗氮法对AISI 304奥氏体不锈钢进行表面处理。将样品放置于阳极电位,在440~520℃范围内,渗氮处理8 h。分析了渗氮层的微观组织结构与形貌,并考察了渗氮前后的摩擦磨损性能。结果表明:在低温440℃下,在表面制备了高硬度的S相强化层。XRD与TEM表明S相为面心立方结构,且无Cr N相析出。高温520℃渗氮表面硬度值(1100 HV0.1)是基体的5倍,但Cr N相明显析出。在干摩擦条件下,渗氮处理后的摩擦系数在0.8左右,相对渗氮前降低约0.2,特别是磨损率只有渗氮前的十分之一量级。磨损机制从原始基体的严重粘着转变为轻微的氧化和磨粒磨损。In order to avoid the inherent shortcomings of conventional direct current plasma nitriding such as damage to parts caused by arcing and the edge effect, AISI 304 austenitic stainless steels were anodic nitrided by means of the active screen plasma nitriding. The nitriding experiments were carried out at 440-520 ℃ for 8 h under anodie potential. The surface morphology, microstructure and phases of the nitrided layer were studied, and tribological properties of the nitrided layer were investigated. The results show that the nitrided layer （S-phase） is formed on the AISI304 austenitic stainless steel surface after nitriding at 440 ℃. XRD and TEM results show that the surface hardening layer is almost composed of the face-centered cubic structure of S-phase without the CrN precipitated phase. With increasing nitriding temperature to 520 ℃ , the mierohardness values reach 1100 HV0. 1, which is about 5 times of that of the untreated substrate, while the CrN phase is clearly detected. Under the dry friction, the friction coefficient of the steel after different nitriding treatment is about 0. 8, compared to the original sample, the coefficient decreases by 0.2, and the wear rate is only the original one-tenth order of magnitude. The wear mechanisms change from the severe adhesive and abrasive wear for the untreated steel to the slight oxidative and abrasive wear for the treated steel.

关 键 词：离子渗氮 AISI304奥氏体不锈钢 投射电镜 摩擦磨损 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG156.8[金属学及工艺—金属材料]