摘要
铁素体-奥氏体双相不锈钢在H_2S-Cl^-_H_2O系统中可发生应力腐蚀开裂行为。为研究其开裂原因,用金相显微镜、电子探针、扫描电子显微镜等手段对断裂试样进行了分析,结果表明:在应力腐蚀开裂的过程中存在奥氏体相或铁素体相的选择性腐蚀;改变系统的pH值和Cl^-含量可使由铁素体和奥氏体构成的微电池的极性发生转变。
Stress corrosion cracking of duplex stainless steels may occur in H2S saturated aqueous solutions containing Cl-. In this study, metallographic microscopy, EPMA, and SEM were used to analyse the cracking behaviour of the duplex stainless steel 00Cr18Ni5Mo3Si in different solution. In solution (b) : saturated H2S+5%NaCl+0.5%CH3COOH, pH=3.0-4.5 and solution (c) : saturated H2S+5%NaCl+0.5%CH3COOH+ 0.01%Na2CO3, pH=4.3-4.6, selective corrosion of individual phasses was observed during stress corrosion cracking. The ferrite corroded while the austenite was not attacked. In solution (d): saturated H2S+0.5%NaCl+0.5%CH3COOH+HCl(pH≈1), on the contray, the austenite corroded and the ferrite was only slightly attacked. Perhaps the potential reversal of the austenite and the ferrite took place in the presence of HC1 in the H2S saturated solution.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1998年第1期47-51,共5页
Journal of Chinese Society For Corrosion and Protection
关键词
应力腐蚀开裂
选择性腐蚀
双相不锈钢
Stress corrosion cracking, Selective cracking, Duplex stainless steel
