980 high-strength steel has been widely used in marine engineering structures due to its high strength and toughness.However,it is easily affected by the harsh environmental conditions(such as the presence of sulfate-...980 high-strength steel has been widely used in marine engineering structures due to its high strength and toughness.However,it is easily affected by the harsh environmental conditions(such as the presence of sulfate-reducing bacteria,SRB),leading to the risk of stress corrosion cracking(SCC).In this paper,the effects of SRB and its metabolites on hydrogen permeation and SCC mechanism of 980 steel in seawater solution were investigated by slow strain rate tensile test,scanning electron microscope,Xray energy spectroscopy,Raman spectroscopy and Devanathan-Stachurski double electrolytic cell.Results demonstrated that the SCC susceptibility of 980 steel was promoted in the presence of SRB,which was related to the cultivation time of the bacteria.When SRB were cultivated for 3 d and 6 d,the SCC mechanism was controlled by hydrogen-induced cracking(HIC);while the cultivation time extended to 11 d,the SCC of 980 steel was under the combined effect of the anodic dissolution(AD) and HIC mechanism.When cultivated for 16 d,the SCC of 980 steel was caused by the dominant AD.Both the SRB accelerated hydrogen permeation under cathodic depolarization process and SRB assisted AD(pitting corrosion)played an enhancing role in promoting SCC susceptibility of 980 steel.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51871204 and U1706221)。
文摘980 high-strength steel has been widely used in marine engineering structures due to its high strength and toughness.However,it is easily affected by the harsh environmental conditions(such as the presence of sulfate-reducing bacteria,SRB),leading to the risk of stress corrosion cracking(SCC).In this paper,the effects of SRB and its metabolites on hydrogen permeation and SCC mechanism of 980 steel in seawater solution were investigated by slow strain rate tensile test,scanning electron microscope,Xray energy spectroscopy,Raman spectroscopy and Devanathan-Stachurski double electrolytic cell.Results demonstrated that the SCC susceptibility of 980 steel was promoted in the presence of SRB,which was related to the cultivation time of the bacteria.When SRB were cultivated for 3 d and 6 d,the SCC mechanism was controlled by hydrogen-induced cracking(HIC);while the cultivation time extended to 11 d,the SCC of 980 steel was under the combined effect of the anodic dissolution(AD) and HIC mechanism.When cultivated for 16 d,the SCC of 980 steel was caused by the dominant AD.Both the SRB accelerated hydrogen permeation under cathodic depolarization process and SRB assisted AD(pitting corrosion)played an enhancing role in promoting SCC susceptibility of 980 steel.
