VN复合渗层的制备及对45~#耐磨性能的影响  

Preparation of VN Composite Layer and Its Influence on Wear Resistance of 45~# Steel

作　　者：黄玲 张进[1] 孙才沅 蒲帅 HUANG Ling;ZHANG Jin;SUN Cai-yuan;PU Shuai(Southwest Petroleum University, Chengdu 610500, China)

机构地区：[1]西南石油大学,成都610500

出　　处：《表面技术》2018年第6期57-62,共6页Surface Technology

基　　金：能源材料电化学科研创新团队校级项目(2015CXTD04);四川省高校油气田材料重点实验室项目(X151516KCL02)~~

摘　　要：目的对45~#强化处理,提高其强韧性和耐磨性。方法采用热反应扩散法(TRD)对45~#基体进行了3种不同的处理,分别为单渗钒、先渗氮后渗钒及先渗钒后渗氮处理。通过扫描电子显微镜、X射线衍射仪进行了微观形貌和物相组成的分析,采用维氏硬度计和旋转摩擦仪对渗层的硬度及耐磨性能进行分析。结果 TRD法处理后,在45~#表面形成一层均匀致密的渗层,其中单渗钒层的厚度为3.86μm,先渗氮后渗钒渗层(先渗氮层)厚度为6.02μm,先渗钒后渗氮渗层(先渗钒层)厚度为8.44μm。单渗钒层的硬度值在1306.6HV左右,而氮化钒渗层的硬度在1549.2~1710.4HV左右,均比处理前试样的硬度(295HV)有明显提高。单渗钒层是由α-Fe和VC相组成,而复合渗层是由VN、α-Fe、Fe_3N和Fe_2C相组成。渗层与基体之间的界面明显,且存在过渡层。单渗钒层试样的平均摩擦系数为0.22,先渗氮层的平均摩擦系数为0.18,先渗钒层的平均摩擦系数为0.20,均小于45~#基体的摩擦系数(为0.29)。结论 TRD法处理后形成的VC、VN渗层能提高钢基体的表面硬度和耐磨性,且钒元素和氮元素渗入的先后顺序对渗层的力学性能有影响。先渗氮层试样效果最佳,往复摩擦实验表明,试样的耐磨性顺序为:先渗氮层>先渗钒层>单渗钒层>45~#基体。The work aims to improve toughness and wear resistance of 45^# steel by performing surface strengthening treatment. Three different kinds of treatment were performed to 45^# steel substrate in TRD method, which were single-osmosis vanadation, penetration vanadation after first nitriding and nitriding pre-infiltration. Microstructure, phase composition and hardness of the layer were analyzed with scanning electron microscope, X-ray diffractometer and Vickers hardness tester, respectively. Wear resistance of the coating was analyzed with ball-on-disk configuration. After TRD treatment, a uniform and dense layer took shape on the 45^# steel, the single vanadium layer was 3.86 μm thick, the penetrated vanadium layer after first nitriding（first nitriding layer） was 6.02 μm thick, and the nitrided layer after first penetrated vanadium（first vanadizing layer） was 8.44 μm thick. Hardness of single-osmosis vanadium was about 1306.6 HV, while that of vanadium nitride layer was 1549.2~ 1710.4 HV, obviously higher than that of the pre-treatment sample（295 HV）. The single-permeable vanadium diffusion layer was composed of α-Fe and VC, while the composite layer was composed of VN, α-Fe, Fe3N and Fe2C. There was visible interface between the diffusion layer and the substrate, and there was transition layer as well. Average friction coefficient of single vanadium sample was 0.22, that of first nitriding layer was 0.18, and that of the first vanadizing layer was 0.20, which were all below that of 45^# steel substrate（0.29）. The VC and VN layers forming after TRD treatment could improve surface hardness and wear resistance of the substrate. Order of element penetration has effects on mechanical properties of the layer. The reciprocating friction experiment shows that the order of wear resistance is as follows： first nitriding layerfirst vanadizing layersingle vanadium layer45~# steel substrate.

关 键 词：盐浴渗氮 粉末渗钒 氮化钒渗层 显微结构 耐磨性 

分 类 号：TG156.8[金属学及工艺—热处理]