实验技术与管理2025，Vol.42Issue(3)：60-71,12.DOI:10.16791/j.cnki.sjg.2025.03.008
金沙江水电站水力量测管道焊接区域的失效行为研究
Study on the failure behavior of the welded joints of hydropower monitoring pipelines at Jinsha River Hydroelectric Station
摘要
Abstract
[Objective]As a key hydropower project in the"West-to-East Power Transmission"initiative,the Jinsha River Hydropower Station faces significant risks of monitoring pipeline corrosion due to its complex water environment,which can seriously threaten the station's safe operation,especially in welded joints in pipelines.This paper systematically investigated the corrosion behavior and failure mechanisms of welded joints in monitoring pipelines,with a focus on environmental factors,material microstructures,and the synergistic effects of chloride ions and sulfate-reducing bacteria(SRB).[Methods]The research aimed to provide actionable insights for enhancing the durability and operational reliability of hydropower monitoring pipelines.This study employed a multidisciplinary approach to conduct an in-depth failure analysis of retired SUS 201 stainless steel monitoring pipelines from the Jinsha River Hydropower Station.The research methodology comprised the following key aspects.1)Water quality analysis:water samples were systematically collected and analyzed at multiple time points to monitor critical parameters,including chloride,sulfate,calcium,and magnesium concentrations,total hardness,and pH levels.2)Material characterization:the chemical composition,microstructure,and phase distribution of welded joints were examined using scanning electron microscopy and energy-dispersive spectroscopy.3)Failure mechanism analysis:corrosion phenomena,such as stress corrosion cracking(SCC)and microbial-induced corrosion(MIC),were investigated in detail.Furthermore,special emphasis was placed on understanding how chloride penetration,SRB activity,and nonmetallic inclusions(e.g.,manganese silicate)contribute to crack initiation and propagation.4)Microbial corrosion analysis:the influence of SRB on localized pitting corrosion and FeS deposit formation was assessed,with a focus on their role in intensifying corrosion propagation.[Results]The results of this paper revealed several key findings.1)Environmental influence:seasonal water quality variations,particularly during the rainy season,led to significant rises in the chloride(148.4%)and sulfate(46.8%)concentrations,which considerably increased the susceptibility of welded joints to corrosion.2)Microstructural vulnerabilities:welded joints displayed manganese silicate inclusions and chromium segregation along grain boundaries,which acted as preferential sites for chloride-induced corrosion and stress accumulation.3)SCC influence:under operational pressures ranging from 1.1 to 1.2 MPa,cracks originated from weak points along grain boundaries and propagated vertically and laterally through the weld fusion zone,leading to structural failure.4)SRB influence:the oxygen-depleted and stagnant water environment inside pipelines facilitated SRB activity,resulting in the deposition of FeS on metal surfaces and within corrosion pits.These deposits disrupted the electrochemical balance,accelerating pitting and intergranular corrosion processes.5)Corrosion product composition:corrosion product analysis identified Fe2O3,FeCr2O4,SiO2,and CaCO3 as the primary constituents.The corrosion layers were porous and poorly adherent,providing minimal protection against continued chloride ingress and subsequent damage progression.Thus,this study offered a comprehensive insight into failure mechanisms governing corrosion in the welded joints of SUS 201 stainless steel monitoring pipelines at the Jinsha River hydropower station.[Conclusions]Key conclusions from this study are as follows:1)seasonal fluctuations in water quality,particularly in the chloride and sulfate concentrations,play a dominant role in driving corrosion progression;2)microstructural defects,including manganese silicate inclusions and chromium segregation,significantly reduce the resistance of grain boundaries to chloride-induced corrosion and stress cracking;3)SCC and MIC are the principal failure mechanisms,with SRB activity amplifying localized damage;4)the porous and nonprotective nature of the corrosion products fails to inhibit chloride ingress,perpetuating ongoing damage to pipeline materials.关键词
金沙江/氯化物/硅酸锰夹杂/晶界腐蚀/SRB微生物腐蚀Key words
Jinsha River/chloride ion/manganese silicate inclusions/intergranular corrosion/SRB microbial corrosion分类
矿业与冶金引用本文复制引用
陶吉全,姚旸,贺秀儒,罗前林,段韦,王涛,程杰明,李辉,胡莹,安江峰..金沙江水电站水力量测管道焊接区域的失效行为研究[J].实验技术与管理,2025,42(3):60-71,12.基金项目
中国长江电力股份有限公司项目"金沙江梯级水电站常用金属材料的腐蚀机理及防护应用研究"(Z522302020) （Z522302020）
