Enhancement of Pitting Corrosion Resistance of Austenitic Stainless Steel Through Deposition of Amorphous/Nanocrystalline Oxy-nitrided Phases by Active Screen Plasma Treatment

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 21; no. 6; p. 1
• Main Authors: Li, Yang, He, Yongyong, Qiu, Jianxun, Zhao, Jun, Ye, Qianwen, Zhu, Yijie, Mao, Junyuan
• Format: Journal Article
• Language: English; Portuguese
• Published: Sao Carlos Universidade Federal do Sao Carlos, Departamento de Engenharia de Materiais 01.01.2018; ABM, ABC, ABPol; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Atomic force microscopy; austenitic stainless steel; Austenitic stainless steels; Chromium nitride; Corrosion resistance; Corrosion resistant steels; Deposition; Diffusion layers; Duplex stainless steels; ENGINEERING, CHEMICAL; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; Microscopes; Microscopy; Nitriding; oxy-nitrided; Photoelectrons; Pitting (corrosion); Scanning electron microscopy; Sodium chloride; Stainless steel; X ray spectra; X-ray diffraction; XPS; oxy-nitrided; Pitting corrosion; XPS; austenitic stainless steel
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2017-0697

In this research, AISI 304 austenitic stainless steels were efficient treatment using active screen plasma oxy-nitriding technique. The modified layers were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopes, and atomic force microscopy. In addition, the pitting corrosion resistances of untreated and oxy-nitrided samples were analyzed by polarization method in 3.5 wt.% NaCl solution. The results showed that a duplex-layer consisting of a deposition layer and a diffusion layer (including CrN+α phase and nitrogen expanded austenite phase) was generated. Special concern has been given to the formation of an amorphous top layer for the deposition of nano sized oxy-nitrides. It believed that the deposition layer of oxy-nitrides formed on steel surface during active screen plasma oxy-nitriding that lead to improved corrosion resistance of AISI 304 austenitic stainless steel, so that the pitting corrosive attack can be avoided.