1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi,China 2. Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China 3. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China 4. Technology Center of Taiyuan Iron and Steel Group Co., Ltd., Taiyuan 030003,Shanxi, China
Chi Phase after Short-term Aging and Corrosion Behavior in 2205 Duplex Stainless Steel
1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi,China 2. Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China 3. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China 4. Technology Center of Taiyuan Iron and Steel Group Co., Ltd., Taiyuan 030003,Shanxi, China
ժҪ Correlation between pitting corrosion behavior and chi (��) phase formed after a short-term aging (5, 10 and 15 min) at 850 �� of 2205 duplex stainless steel (DSS) was investigated using potentiodynamic polarization tests, optical microscopy, and scanning electron microscopy equipped with energy-dispersive spectrum system. Results showed that after aging for 5 min, the �� phase initially precipitated at ferrite grain boundaries, developed and then became linked with prolonging aging time. The �� phase was rich in Cr and Mo, resulting in formation of depleted zones nearby. The �� phase could reduce corrosion resistance of DSS and slightly influence its stability, but the specimens still displayed the capacity for repassivation. Some lines of evidence showed that stable pitting corrosion initiated at the boundaries of precipitates. The �� phase was selectively corroded during the first stage of corrosion and then the depleted zones nearby were attacked. In addition, the grain size and volume of precipitates also affected pit nucleation and progress, and suitable size and distribution of �� phase could aggravate pit initiation at precipitate boundaries. The �� phase with considerably low volume fraction and small size was not sensitive position for pit initiation.
Abstract��Correlation between pitting corrosion behavior and chi (��) phase formed after a short-term aging (5, 10 and 15 min) at 850 �� of 2205 duplex stainless steel (DSS) was investigated using potentiodynamic polarization tests, optical microscopy, and scanning electron microscopy equipped with energy-dispersive spectrum system. Results showed that after aging for 5 min, the �� phase initially precipitated at ferrite grain boundaries, developed and then became linked with prolonging aging time. The �� phase was rich in Cr and Mo, resulting in formation of depleted zones nearby. The �� phase could reduce corrosion resistance of DSS and slightly influence its stability, but the specimens still displayed the capacity for repassivation. Some lines of evidence showed that stable pitting corrosion initiated at the boundaries of precipitates. The �� phase was selectively corroded during the first stage of corrosion and then the depleted zones nearby were attacked. In addition, the grain size and volume of precipitates also affected pit nucleation and progress, and suitable size and distribution of �� phase could aggravate pit initiation at precipitate boundaries. The �� phase with considerably low volume fraction and small size was not sensitive position for pit initiation.
��������:National Natural Science Foundation of China;Natural Science Foundation of Shanxi Province;Special Scientific Research Fund for the Doctoral Program of Higher Education
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E-mail: hanpeide@126.com
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Qi SUN,,Jian WANG,,Hua-bing LI,Yue LI,,Ya-di HU,,Jin-gang BAI,Pei-de HAN,. Chi Phase after Short-term Aging and Corrosion Behavior in 2205 Duplex Stainless Steel[J]. �й������ڿ���, 2016, 23(10): 1071-1079.
Qi SUN,,Jian WANG,,Hua-bing LI,Yue LI,,Ya-di HU,,Jin-gang BAI,Pei-de HAN,. Chi Phase after Short-term Aging and Corrosion Behavior in 2205 Duplex Stainless Steel. Chinese Journal of Iron and Steel, 2016, 23(10): 1071-1079.
2016, Vol. 23 
