Effect of Niobium Addition on the High-Temperature Oxidation Behavior of 22Cr25NiWCoCu Stainless Steel in Air
Sheng-Yao Huang,
Wen-Ta Tsai,
Yeong-Tsuen Pan,
Jui-Chao Kuo,
Hsien-Wei Chen,
Dong-Yih Lin
Affiliations
Sheng-Yao Huang
Department of Materials Science and Engineering, National Cheng-Kung University, Tainan 701, Taiwan
Wen-Ta Tsai
Department of Materials Science and Engineering, National Cheng-Kung University, Tainan 701, Taiwan
Yeong-Tsuen Pan
New Materials Research & Development Department, China Steel Corporation, Kaohsiung City 812, Taiwan
Jui-Chao Kuo
Department of Materials Science and Engineering, National Cheng-Kung University, Tainan 701, Taiwan
Hsien-Wei Chen
Department of Materials Science and Engineering, City University of Hong Kong, 4/F Fong Yun Wah Building, Tat Chee Avenue, Kowloon 999077, Hong Kong, China
Dong-Yih Lin
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung City 811, Taiwan
The oxidation behavior of 22Cr25NiWCoCu stainless steel with 0−0.86 wt.% Nb addition was investigated at 900 °C in air. With an increase in Nb addition, the volume fraction and average particle size of Nb (C, N) increased, but the grain size decreased. The results of grazing incidence X-ray diffraction indicated that the steels with Nb additions promoted Cr2O3 formation. After 10−100 h of oxidation, Cr depletion occurred at the region with Nb (C, N) precipitates because of its high Cr consumption rate, leading to Fe oxide generation. Finally, after 100 h of oxidation, the outer layer of Fe2O3 and the inner layer of (Cr, Fe, Mn)3O4 were formed.
