Low temperature nitriding of AISI 300 and 200 series austenitic stainless steels
Low temperature nitriding of AISI 300 and 200 series austenitic stainless steels
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DOI：
10.1016/j.vacuum.2016.02.009
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发表时间：
2016-05-01
期刊：
影响因子：
4
通讯作者：
Bacci, Tiberio
中科院分区：
文献类型：
--
作者：
Borgioli, Francesca;Galvanetto, Emanuele;Bacci, Tiberio
在这项研究中，低温离子渗氮对不同的奥氏体不锈钢，CrNi基（AISI 304L和AISI 316L）和CrMn基（AISI 202）的特性的影响进行了比较。分别在400 ℃和430 ℃、1000 Pa、5 h条件下对试样进行氮化处理，并对其显微组织、相组成、显微硬度和耐蚀性进行了评价。改性层的特性取决于处理参数和合金成分。对于所有的钢改性表面层具有双层显微组织。在主要由S相组成的外变质层中，在晶粒中观察到变形（或剪切）带，并形成氮诱导的h.c.p.马氏体，N ′（N ′）。AISI 202试样的剪切带和e'N的形成趋势较高，而AISI 304L和AISI 316L试样的剪切带和e'N的形成趋势较低，从而影响改性层的厚度。当在430 ℃下进行渗氮时，形成氮化物，并且其量受钢组成的影响。氮化处理允许显着增加表面显微硬度和耐腐蚀性，与未经处理的合金相比。当氮化物没有形成时，对于400 ℃氮化样品，所考虑的钢的腐蚀行为是相当的。氮化物沉淀影响耐腐蚀性，增加腐蚀现象。(C)2016爱思唯尔有限公司版权所有
In this study the effects of low temperature plasma nitriding on the characteristics of different austenitic stainless steels, CrNi-based (AISI 304L and AISI 316L) and CrMn-based (AISI 202), were compared. Samples were nitrided at 400 and 430 degrees C, at 1000 Pa for 5 h, and their microstructure, phase composition, microhardness and corrosion resistance were evaluated. The characteristics of modified surface layers depended on both treatment parameters and alloy composition. For all the steels modified surface layers had a double layer microstructure. In the outer modified layer, mainly consisting of S phase, deformation (or shear) bands were observed in the grains, and nitrogen induced h.c.p. martensite, epsilon(N)', formed. The tendency to form shear bands and e'N was higher for AISI 202 samples, and decreased for AISI 304L and then for AISI 316L ones, influencing the modified layer thickness. When nitriding was performed at 430 degrees C, nitrides formed, and their amount was affected by steel composition. Nitriding treatments allowed to markedly increase surface microhardness and corrosion resistance, in comparison with the untreated alloys. When nitrides did not form, as for the 400-degrees C nitrided samples, the corrosion behaviour of the considered steels was comparable. Nitride precipitation affected corrosion resistance, increasing corrosion phenomena. (C) 2016 Elsevier Ltd. All rights reserved.