سال انتشار: ۱۳۹۱

محل انتشار: سومین کنفرانس بین المللی عملیات حرارتی مواد

تعداد صفحات: ۹

نویسنده(ها):

N. Karimzadeh – Department of Materials Engineering, Islamic Azad University , Najafabad Branch, Isfahan, Iran
k Raeissi – Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
m Mirjani – Department of Materials Engineering, Islamic Azad University , Najafabad Branch, Isfahan, Iran
a Saatchi – Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran

چکیده:

In this research, the microstructure and corrosion properties of plasma nitriding and post oxidation treated AISI 316 austenitic stainless steel have been studied. Plasma nitriding was carried out at 450 °C for 5 hr in a D.C plasma with gas mixture of 25% N2- 75% H2 followed by post-oxidation process in gas mixtures of O2/H2: 1/3, 1/5, 1/9 and 1/12 for 30 min. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical polarization readings. The results showed that the plasma nitriding decreases the corrosion resistance of the steel substrate. However, post-oxidizing treatment improves both uniform and pitting corrosion resistances of the nitrided specimens. This effect was most pronounced by post-oxidizing treatment at lower O2/H2 ratios due to the development of magnetite as a more dense oxide phase