Stress corrosion cracking failure of X80 carbon steel U-b end cause d by Desulfovibrio vulgaris biocorrosion  

作　　者：Zhong Li Jike Yang Shihang Lu Wenwen Dou Tingyue Gu 

机构地区：[1]Corrosion&Protection Center,University of Science&Technology Beijing,Beijing 100083,China [2]Institute of Marine Science and Technology,Shandong University,Qingdao 266237,China [3]Department of Chemical and Biomolecular Engineering,Institute for Corrosion and Multiphase Technology,Ohio University,Athens,OH 45701,USA

出　　处：《Journal of Materials Science & Technology》2024年第7期95-105,共11页材料科学技术（英文版）

基　　金：supported by National Natural Science Foundation of China(No.U2106206);Institute of Marine Science and Technology,Shandong Univer-sity,China.

摘　　要：Sulfate reducing bacteria(SRB)are widely present in oil and gas industry,causing pitting corrosion on pipeline steel.Stress corrosion cracking(SCC)often occurs in the presence of mechanical stress before pit-ting perforation failure,leading to economic losses and even catastrophic accidents.In this study,stress distribution simulation using the finite element method(FEM),corrosion analysis techniques and elec-trochemical corrosion measurements were employed to investigate the SCC mechanism of X80 pipeline steel caused by Desulfovibrio vulgaris,which is a common SRB strain used in microbiologically influenced corrosion(MIC)studies.It was found that D.vulgaris MIC caused sharp microcracks on an X80 U-bend coupon after only 2 weeks of immersion at 37℃in the deoxygenated ATCC 1249 culture medium inocu-lated with D.vulgaris.The X80 U-bend coupon’s weight loss-based uniform corrosion rate for the 12 cm^(2)surface was 60%of that for the unstressed flat square coupon(2.3 mg cm^(−2)vs.3.8 mg cm^(−2)).This was likely because the square coupon had wide MIC pits,providing a larger effective surface area for more sessile cells(4.2×10^(8)cells cm^(−2)on square coupon vs.2.4×10^(8)cells cm^(−2)on U-bend coupon)to attach and harvest more electrons.An SCC failure occurred on an X80 U-bend pre-cracked at the outer bottom after a 6-week immersion in the D.vulgaris broth.Apart from MIC damage,this could also be because D.vulgaris metabolism increased the availability hydrogen atoms on the steel surface,and promoted the diffusion of hydrogen atoms into the metal lattice,thus increasing the brittleness of the steel.

关 键 词：Stress corrosion cracking Microbiologically influenced corrosion Sulfate reducing bacteria X80 U-bend steel Tensile stress 

分 类 号：TG146.23[一般工业技术—材料科学与工程]