金属材料在超临界水中动态腐蚀特性  

Dynamic corrosion characteristics of metal materials in supercritical water

作　　者：刘云帆 雷贤良[1] 苟灵通 李德标 LIU Yunfan;LEI Xianliang;GOU Lingtong;LI Debiao(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Xi’an Special Equipment Inspection Institute,Xi’an 710065,China)

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049 [2]西安特种设备检验检测院,西安710065

出　　处：《材料工程》2023年第11期61-70,共10页Journal of Materials Engineering

基　　金：国家重点研发计划资助项目(2018YFB0604403);国家市场监督管理总局科技资助项目(2019MK071)。

摘　　要：采用超临界流体静、动态腐蚀实验平台,对Q235,304,316L,P91,N80,3Cr13六种材料在超临界水拟临界区(22.5 MPa,375.6℃)和类气相区(22.5 MPa,407.6℃)环境下进行72 h的静态及动态腐蚀实验研究。结果表明:材料在超临界水环境中的动态腐蚀速率明显高于静态腐蚀速率,流动加速腐蚀进程,其中304提升4倍以上;同时,随着材料耐腐蚀性的降低,动态条件对腐蚀增重的强化作用减弱。动态条件加剧腐蚀的因素为:流动剪切力加速超临界流体中的腐蚀性介质向基体表面移动,促进腐蚀化学反应的进行;流动剪切力对材料表面冲刷,促进材料表面Fe的溶解,加快腐蚀化学反应;剪切力的冲刷作用促进腐蚀产物晶体在壁面形成过程中的脱落,加速腐蚀进程。The static and dynamic corrosion experimental platforms of supercritical fluid reactor were used for the static and dynamic corrosion test of Q235,304,316L,P91,N80 and 3Cr13 in the supercritical water pseudo-critical region(22.5 MPa,375.6℃)and gas-like region(22.5 MPa,407.6℃)for 72 h.The results show that the dynamic corrosion rate of materials in supercritical water environment is significantly higher than the static corrosion rate,and the flow accelerates the corrosion process,in which 304 is increased by more than 4 times;the strengthening effect of dynamic conditions on corrosion mass gain is weakened with the decrease of corrosion resistance.The factors that exacerbate corrosion under dynamic conditions are:flow shear force accelerates the movement of the corrosive medium in the supercritical fluid to the substrate surface,promoting the corrosion chemical reaction;the flow shear force scours the material surface,promotes the dissolution of Fe on the material surface,and accelerates the corrosion chemical reaction;the erosion effect of shear force promotes the detachment of corrosion product crystals during the formation process of the wall,accelerating the corrosion process.

关 键 词：超临界水 金属材料 动态腐蚀 腐蚀机理 

分 类 号：TG178[金属学及工艺—金属表面处理]