Properties of rapid arc discharge plasma nitriding of AISI 420 martensitic stainless: effect of nitriding temperatures
Properties of rapid arc discharge plasma nitriding of AISI 420 martensitic stainless: effect of nitriding temperatures
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DOI：
10.1016/j.jmrt.2022.07.028
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发表时间：
2022-07
期刊：
影响因子：
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通讯作者：
Ji Sun;Jie Li;J.M. Xie;Yang Yang-Yang;W. Wu;Xiang Zhou;S.H. Zhang;Q.M. Wang
中科院分区：
文献类型：
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作者：
Ji Sun;Jie Li;J.M. Xie;Yang Yang-Yang;W. Wu;Xiang Zhou;S.H. Zhang;Q.M. Wang
具有优异机械性能的马氏体不锈钢（MSS）是核工业、船舶工业、航空航天工业的潜在候选材料。然而，需要进行表面处理来提高MSS的耐磨性能。对选定的 AISI 420 不锈钢进行电弧放电等离子氮化（ADPN），在不降低其原有耐腐蚀性的情况下提高耐磨性能。为了避免形成 CrN 相，ADPN 在 400°C 至 460°C 的温度范围内进行 1 小时。分别通过X射线衍射(XRD)、扫描电子显微镜(SEM)、维氏显微硬度计和球盘摩擦试验机研究了氮化温度对氮化层的结构、力学和摩擦学性能的影响。使用 3.5% NaCl 溶液中的动电位极化来评估耐腐蚀性。 400℃氮化的试样表面为ε-Fe2-3N相，而更高温度氮化的试样表面为αN相。借助高密度、高能量的氮等离子体，在460℃下1小时内氮化层厚度可达15μm，表现出极高的氮化效率。在 400 °C 下氮化的试样上的脆性 Fe2-3N 相层导致耐磨性不理想，具有严重的磨料磨损行为，但具有优异的腐蚀性能。在 460 °C 下氮化的样品表现出优异的耐磨性，但由于钛颗粒覆盖的微观结构而降低了腐蚀性能。在 420 和 440 °C 下氮化的样品具有理想的磨损和腐蚀性能以及优异的表面质量。
Martensitic stainless steels (MSS) with excellent mechanical properties are potential candidates used in the nuclear, marine, aeronautical, and aerospace industries. However, surface treatments are needed to improve the wear performance of MSS. Arc discharge plasma nitriding (ADPN) was applied on selected AISI 420 stainless steel to improve the wear performance without reducing its original corrosion resistance. To avoid the formation of the CrN phase, the ADPN was performed at temperatures ranging from 400 °C to 460 °C for 1 h. The effects of nitriding temperature on the structural, mechanical, and tribological properties of the nitrided layers were examined by X-ray diffraction (XRD), Scanning electron microscope (SEM), Vickers microhardness tester, and ball-on-disk tribometer, respectively. Potentiodynamic polarization in a 3.5% NaCl solution was used to assess corrosion resistance. The surface of the specimen nitrided at 400 °C is ε-Fe2-3N phase while that of specimen nitrided at higher temperature isαNphase. The thickness of the nitrided layer could reach 15 μm in 1 h at 460 °C in virtue of the high-density and high-energy nitrogen plasma, which showed an extremely high nitriding efficiency. The brittle Fe2–3N phase layer on specimen nitrided at 400 °C contributes to unsatisfactory wear resistance with severe abrasive wear behavior, however, excellent corrosion properties. The specimen nitrided at 460 °C shows superior wear resistance but degraded corrosion property due to Ti particles covered microstructure. The specimen nitrided at 420 and 440 °C possess desirable wear and corrosion performance, as well as excellent surface quality.