Corrosion Behavior of Low-Alloy Pipeline Steel with 1% Cr Under CO2 Condition
来源期刊：Acta Metallurgica Sinica2015年第6期
论文作者：Zhen-Guang Liu Xiu-Hua Gao Chi Yu Lin-Xiu Du Jian-Ping Li Ping-Ju Hao
文章页码：739 - 747
摘 要：Carbon dioxide corrosion behavior of low-alloy pipeline steel with 1% Cr exposed to CO2-saturated solution was investigated by immersion experiment. SEM, EDX, TEM, EPMA and XRD were utilized to investigate the microstructure, corrosion morphologies, corrosion phases and elements distribution of corrosion scale. The results demonstrate that the microstructure of tested steel consists of ferrite and carbides. During the corrosion process, ferrite dissolves preferentially, leaving carbide particles behind. The residual carbide particles may promote the nucleation of Fe CO3 crystal. The phase comprising of the inner layer is Cr compound, and the one of the outer layer is Fe CO3. The formation process of corrosion scale can be illustrated as follows: Firstly, a thin scale consisting of thin inner layer and outer layer is formed, which represents poor corrosion resistance; then, the inner layer changes little, once it has been formed, and the outer layer becomes thick and compact, which demonstrates that a fine corrosion resistance is obtained. The chemical elements of chromium and molybdenum accumulate in the inner layer of corrosion scale. The corrosion behavior of lowalloy steel based on microstructure and morphology characterization is also discussed.
Zhen-Guang Liu1，Xiu-Hua Gao1，Chi Yu2，Lin-Xiu Du1，Jian-Ping Li1，Ping-Ju Hao3
1. The State Key Lab of Rolling and Automation, Northeastern University2. School of Resource and Material, Northeastern University at Qinhuangdao3. Mechanical and Electrical Engineering, Shijiazhuang Vocational College for Scientific and Technical Engineering
摘 要：Carbon dioxide corrosion behavior of low-alloy pipeline steel with 1% Cr exposed to CO2-saturated solution was investigated by immersion experiment. SEM, EDX, TEM, EPMA and XRD were utilized to investigate the microstructure, corrosion morphologies, corrosion phases and elements distribution of corrosion scale. The results demonstrate that the microstructure of tested steel consists of ferrite and carbides. During the corrosion process, ferrite dissolves preferentially, leaving carbide particles behind. The residual carbide particles may promote the nucleation of Fe CO3 crystal. The phase comprising of the inner layer is Cr compound, and the one of the outer layer is Fe CO3. The formation process of corrosion scale can be illustrated as follows: Firstly, a thin scale consisting of thin inner layer and outer layer is formed, which represents poor corrosion resistance; then, the inner layer changes little, once it has been formed, and the outer layer becomes thick and compact, which demonstrates that a fine corrosion resistance is obtained. The chemical elements of chromium and molybdenum accumulate in the inner layer of corrosion scale. The corrosion behavior of lowalloy steel based on microstructure and morphology characterization is also discussed.
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