【摘要】 低合金钢广泛应用于石油储罐领域，在高应力状态下会导致储罐发生结构受损、失效，易产生泄漏、火灾爆炸等重大事故。为实现损伤监测，减少重大事故发生，开展了基于声发射的低合金钢高应力腐蚀行为研究。首先分析了在320 MPa应力和高浓度Cl~-耦合作用下低合金钢腐蚀过程中的电化学和声发射监测信号特征，结合腐蚀形貌分析其腐蚀行为。结果表明:低合金钢的腐蚀初期为无膜腐蚀，腐蚀产物聚集导致阻抗下降;后期(4～24天)腐蚀产物膜保护性增强使阻抗回升，但表面出现点蚀与裂纹，且声发射在线监测成功捕捉到该过程的特征信号:裂纹萌生时绝对能量高于4000 V·μs，裂纹扩展阶段伴随高振铃计数及高于6000 V·μs的绝对能量信号，证实了声发射技术对高应力状态下低合金钢腐蚀行为实时表征的有效性。更多还原

【Abstract】 Low-alloy steels are widely used in the field of petroleum storage tanks. However,under high-stress conditions,they can cause structural damage and failure of the tanks,leading to major accidents such as leakage,fire,and explosion. To achieve damage monitoring and reduce the occurrence of such serious accidents,research on high-stress corrosion behavior of low-alloy steel based on acoustic emission has been carried out. Firstly,the electrochemical and acoustic emission( AE) monitoring signal characteristics during the corrosion process of low-alloy steel were analyzed under the coupling effect of 320 MPa stress and high concentration Cl~-solution,and the corrosion behavior was studied by combining corrosion morphology analysis. The results show that in the early stage of corrosion,the lowalloy steel undergoes film-free corrosion,and the accumulation of corrosion products leads to a decrease in impedance. In the later stage( 4-24 days),the protective of the corrosion product film improves,resulting in a recovery of impedance,but pitting and cracks are observed on the surface,and the characteristic signals of this process are successfully captured by online acoustic emission monitoring: the absolute energy at crack initiation is higher than 4000 V·μs,and the crack propagation stage is accompanied by high ringing counts and absolute energy signals higher than 6000 V·μs. These findings confirm the effectiveness of acoustic emission technology for real-time characterization of corrosion behavior in low-alloy steel under high-stress conditions.更多还原