Low-temperature plasma nitriding has been widely studied and applied, in enhancing the wear performance of austenitic stainless steels (ASSs) without losing corrosion resistance. In this work the wear and corrosion behaviours of two specialty ASSs, i.e. Staballoy® AG17 (Fe-17Cr-20Mn-0.5N, in wt%) and RA330® (Fe-19Cr-35Ni-1.2Si, in wt%), were evaluated – and compared to AISI 304 – before and after low-temperature triode plasma nitriding (TPN) at 400 °C and 450 °C. A nitrogen interstitially-supersaturated expanded austenite layer (γ_N) was developed for all three ASSs after TPN treatment at 400 °C, which led to a) an approximately 4-fold increase in surface hardness, b) a reduction in specific wear rate of at least 2 orders of magnitude in unlubricated dry-sliding, and c) an improved resistance to pitting in 3.5 wt% NaCl aqueous solution. Large numbers of ‘linear defects’ (identified in TEM studies as strips of HCP-ε_N) were seen in the γ_N-AG17 layer, that could be correlated to comparatively higher surface hardness and better wear resistance. Several slip/shear bands were also seen in the γ_N-330 layer, where short-range Cr-segregation could occur, leading to localised corrosion. More importantly, after TPN treatment at 450 °C, alloys AISI 304 and AG17 presented a deterioration in corrosion performance, whereas good corrosion performance was maintained for alloy RA330. Redistribution of Si (in preference to Cr) was revealed in γ_N-330 after TPN treatment at 450 °C, whereby Si-alloying at a significantly higher level than in the other two alloys investigated appears (in addition to the high Ni content in alloy 330) to be beneficial in delaying CrN precipitation, and thus in maintaining the good corrosion performance of γ_N after nitriding at low-to-intermediate temperatures.

低温等离子体渗氮已得到广泛研究和应用，以提高奥氏体不锈钢（ASS）的耐磨性能而又不降低其耐腐蚀性。在这项工作中，两种特殊ASS的磨损和腐蚀行为分别为Staballoy®AG17（Fe-17Cr-20Mn-0.5N，以重量％计）和RA330®（Fe-19Cr-35Ni-1.2Si，以重量％计）。在400°C和450°C的低温三极管等离子体氮化（TPN）之前和之后进行了评估，并与AISI 304进行了比较。氮间隙膨胀过奥氏体层（_N）是在400°C的TPN处理后为所有三种ASS开发的，这导致a）表面硬度增加了约4倍，b）未润滑的干滑比磨损率降低了至少2个数量级c）改善了在3.5 wt％NaCl水溶液中的抗点蚀性。“线状缺陷”的大量（在TEM研究鉴定为HCP-ε条_Ñ）的上升，在γ _Ñ -AG17层，能够被关联到相对较高的表面硬度和更好的耐磨性。几个滑移/剪切带中也见到在γ _Ñ-330层，可能会发生短距离的Cr偏析，从而导致局部腐蚀。更重要的是，在450°C的温度下进行TPN处理后，AISI 304和AG17合金的腐蚀性能下降，而RA330合金则保持了良好的腐蚀性能。的Si（优先于Cr）的再分配被揭露在γ _Ñ在450℃，从而Si的合金化在显著更高的水平比其他两种合金-330 TPN治疗后研究出现（除了在高Ni含量合金330）是在延迟的CrN沉淀是有利的，并因此在保持γ的良好的耐蚀性能_ñ氮化后在低到中间温度。