Effect of nitrogen addition on microstructure and erosion-corrosion behavior of stainless steel in acidic slurry

作     者：Li Ping Cai Qi zhou Wei Bo kang Li Feng jun 

作者机构：School of Material Science and EngineeringHenan Polytechnic UniversityJiaozuo 454000HenanChina China Yituo Group Co.Ltd.Luoyang 471004HenanChina School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China China Yituo Group Co.Ltd.Luoyang 471004HenanChina 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2009年第6卷第3期

页      面：197-201页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the postdoctoral foundation for Yituo Group Co., Ltd., P. R. China (No.TKJ2008-27) the doctoral foundation for Henan Polytechnic University, Henan (No. B2006-17) 

主　　题：nitrogen microstructure erosion-corrosion (E-C) duplex stainless steels 

摘      要：Effect of nitrogen content on the microstructure and erosion-corrosion (E-C) behavior of stainless steel (containing about 25% Cr, 5%-6% Ni, and 1%-2% Mo) was investigated by using optical microscope(OM), potentiodynamic polarization curve and immersion method, a self-made rotating disk apparatus and scanning electron microscopy (SEM) and so on. The results show that with the increase of nitrogen content from 0 (no adding) to 0.485 wt.%, the Cr(eq)/Ni(eq) ratio of the tested materials decreases from 4.14 to 1.23 and the ferrite volume percentage of the steel tested linearly decreases approximately from 90% to 10%. The effect of nitrogen content on polarization behavior of the studied steel was not significant. All the passive current densities (I(p)) and pure corrosion rates (V(c)) of the different N content specimens in the acidic solution (slurry containing 0.1 M H(2)SO(4)+0.06% Cl(-)+0.4% F(-), the simplified zinc hydrometallurgy slurry) are too low and nearly negligible. Whereas the pure erosion rates (V(e)) of the four scenarios of the steels tested (N content, wt.%: N1, no adding; N2, 0.143%; N3, 0.289%; N4, 0485%, respectively) are much higher than their V(c) values. The V(e) values of the tested steels are in the order of N4 N1 N3 N2, at the same time, the total weight loss rates (V(t)) follow the order of N4 N1 N3 N2, too. N2 steel consisting of approximately equal volume fractions of ferrite (alpha) and austenite (gamma) exhibits the most excellent E-C resistance and erosion resistance, while the stainless steels possessing the big difference between alpha phase and gamma phase, such as N1 steel nearly possessing single ferrite or N4 steel nearly possessing single austenite, show poorer E-C resistance and erosion resistance.