Comparative study of plasma nitriding and plasma oxynitriding for optimal wear and corrosion resistance: Influences of gas composition
Comparative study of plasma nitriding and plasma oxynitriding for optimal wear and corrosion resistance: Influences of gas composition
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DOI：
10.1016/j.jmrt.2021.08.039
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
Yang Yang-Yang;Xiang Zhou;X. Dai;Jie Li;Zhang Sufang;C. S. Zhang;J. Ding;Jun Zheng
中科院分区：
文献类型：
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作者：
Yang Yang-Yang;Xiang Zhou;X. Dai;Jie Li;Zhang Sufang;C. S. Zhang;J. Ding;Jun Zheng
研究了4140钢离子渗氮和离子氧氮共渗层的相结构、显微组织、耐磨性和耐蚀性。在520 °C下对氮气和氢气的混合物进行等离子体氮化。在氧氮化处理期间，在520 °C下以固定的氮气和氢气比例添加普通空气形式的额外氧气。采用光学显微镜、扫描电子显微镜、表面形貌仪、X射线衍射仪、X射线光电子能谱仪、拉曼显微镜、微纳米压痕仪、摩擦磨损试验机和动电位极化测试仪研究了气体成分对渗氮层和氧氮化层性能的影响。试验结果表明，等离子体氮氧化处理后的试样表面形成了一层纳米晶Fe 2 - 3 N相分布的氧化铁层。氧的加入导致不同的相组成、显微组织和表面层厚度，从而导致试样的力学性能、磨损性能和腐蚀性能的差异。在一定的气体成分（N：H：O = 1：1：0.175）下，获得了性能最佳的等离子体氧氮化试样，其耐磨性和耐蚀性均优于等离子体渗氮试样。
The phase structures, microstructures, wear properties, and corrosion resistance of plasma nitrided and plasma oxynitrided 4140 steel were studied. The plasma nitriding was conducted on a mixture of nitrogen and hydrogen at 520 °C. Additional oxygen in the form of plain air was added during oxynitriding treatment in a fixed ratio of nitrogen and hydrogen at 520 °C. The influences of gas composition on properties of the nitrided layer and oxynitrided layer were investigated using an optical microscope, scanning electron microscope, profilometer, X-ray diffractometer, X-ray photoelectron spectroscopy, Raman microscope, micro and nano-indenters, a tribometer, and potentiodynamic polarization testing. Results of tests demonstrate that an iron oxide layer with nanocrystalline Fe2–3N phase distributed forms on the surface of plasma oxynitrided specimens. Oxygen addition leads to different phase compositions, microstructures, and thicknesses of surface layer, which result in differences in mechanical, wear, and corrosion properties of specimens. The plasma oxynitrided specimen with optimal properties was obtained at a certain gas composition (N:H:O = 1:1:0.175), which shows better wear property and corrosion resistance than plasma nitrided specimen.