水-氧-应力联合作用对X80液氨管道应力腐蚀的影响实验  

Water-oxygen-stress coupled effects on liquid ammonia stress corrosion behavior in X80 pipeline steel

作　　者：李加庆 何帅震 赵子峰 冯智雨 尹鹏博 滕霖 江莉龙[1] LI Jiaqing;HE Shuaizhen;ZHAO Zifeng;FENG Zhiyu;YIN Pengbo;TENG Lin;JIANG Lilong(College of Chemical Engineering,Fuzhou University//National Engineering Research Center for Chemical Fertilizer Catalyst//Qingyuan Innovation Laboratory;PipeChina Engineering Technology Innovation Co.,Ltd.)

机构地区：[1]福州大学化工学院·化肥催化剂国家工程研究中心·清源创新实验室 [2]国家管网集团工程技术创新有限公司

出　　处：《油气储运》2025年第3期271-279,共9页Oil & Gas Storage and Transportation

基　　金：国家重点研发计划“氢能技术”专项“高效热化学合成氨催化剂的创制及其批量制备技术”,2021YFB4000403;国家自然科学基金创新研究群体项目“氨能源催化工程”,22221005;国家自然科学基金重点项目“基于缔合加氢机理的高性能亚纳米Ru基合成氨催化剂设计制备及应用基础研究”,22038002;国家自然科学基金青年科学基金项目“高压氢环境铬钼钢储氢容器氢脆失效机理及结构完整性模型研究”,52205145;福建省自然科学基金项目“铬钼钢储氢容器高压氢脆机理及其多尺度研究”,2023J05114。

摘　　要：【目的】在“双碳”目标下,液氨有望成为高效与安全的储氢载体。但在液氨长距离管输过程中,管材易发生液氨应力腐蚀开裂进而引起液氨泄漏事故,威胁液氨管道运行本质安全。因此,探究管线钢液氨应力腐蚀敏感性规律对保障管道安全意义重大。【方法】为分析管线钢在含杂质液氨环境下的应力腐蚀行为,设计并开展了不同含量的水、氧气及不同应力下的X80管线钢C形环法应力腐蚀实验;采用失重法、控制变量法定量分析杂质及应力联合作用对X80管线钢液氨应力腐蚀行为的影响;基于管线钢的腐蚀速率、腐蚀微观形貌及腐蚀产物3个方面,阐明管线钢的液氨应力腐蚀演化规律及内在机理。【结果】在无水液氨环境下,随着氧含量的增加,管线钢腐蚀速率增大;随着应力的增加,管线钢腐蚀速率迅速增大;当在含氧液氨中加入质量分数为0.20%的水,在所研究的氧浓度范围内,管线钢的腐蚀速率均降低。氧浓度与应力的联合作用会诱发管线钢表面形成腐蚀产物:当施加应力为100%屈服强度时,腐蚀产物呈颗粒状沉积形态,且有裂纹萌生与扩展;随着应力进一步增大至125%屈服强度、150%屈服强度时,管线钢表面萌生出更多裂纹且部分相连,腐蚀形貌呈现胶泥状沉积形态并伴有龟裂纹形成。分别加入质量分数为0.20%与1.00%的水,即使在高应力下,管线钢表面仅出现少量微裂纹与腐蚀产物,表明一定量的水杂质能够抑制管线钢的液氨应力腐蚀开裂倾向。【结论】在液氨管道设计、建设及运行过程中,需要考虑氧气杂质的混入、管材的高应力抗力以及管道施工引起的残余应变等因素对液氨管道应力腐蚀开裂的影响,必要时可添加一定量的水降低液氨腐蚀风险,提升高钢级管道的服役安全。[Objective]In the context of the“dual carbon”goals,liquid ammonia is anticipated to serve as an efficient and safe hydrogen storage carrier.However,during long-distance pipeline transportation of liquid ammonia,stress corrosion cracking may occur in the pipes,leading to leakage and compromising the intrinsic safety of the pipeline operation.Therefore,it is crucial to investigate the susceptibility of pipeline steel to stress corrosion from liquid ammonia to ensure pipeline safety.[Methods]To analyze the stress corrosion behavior of X80 pipeline steel in a liquid ammonia environment with impurities,C-ring stress corrosion tests were conducted under varying levels of water,oxygen,and stress.The coupled effects of these impurities and stress on the corrosion behavior were quantitatively assessed using weight loss and control variable methods.This study clarified the evolution and internal mechanisms of liquid ammonia stress corrosion in pipeline steel based on corrosion rates,micro-morphology,and corrosion products.[Results]In anhydrous liquid ammonia environment,the corrosion rate of pipeline steel increased with higher oxygen content and rose sharply with increased stress.When water with a mass fraction of 0.20%was added to oxygen-containing liquid ammonia,the corrosion rates of pipeline steel decreased within the studied range of oxygen concentrations.The coupled effect of oxygen concentration and stress can lead to the formation of corrosion products on the surface of pipeline steel. At 100% of yield strength, corrosion products appeared as granular deposits, and cracks began to initiate and propagate. Asstress increased to 125% and 150% of yield strength, additional cracks formed on the surface of the pipeline steel, partially connecting withone another, while the corrosion morphology shifted to cementitious deposits accompanied by crack formation. When adding water withmass fractions of 0.20% and 1.00%, respectively, only a few microcracks and corrosion products appeared on the surface of pipeline steel,ev

关 键 词：X80管线钢 液氨 水-氧-应力 应力腐蚀 腐蚀速率 

分 类 号：TE832[石油与天然气工程—油气储运工程]