摘要
研究了超临界水反应器运行2000 h后GH4169合金筒体及焊缝处的组织性能。结果表明:高温高压及蔗糖混合溶液条件下GH4169合金筒体的耐蚀性良好,其厚度尺寸损失速率在0.005~0.255μm/h之间,腐蚀产物为金属元素的氧化物、磷酸盐。筒体与其他零件的焊接接头处是影响反应器残余寿命的薄弱环节。筒体与连接件处存在应力腐蚀开裂,经计算其裂纹扩展速率为5.25μm/h,裂纹仅需762 h即可贯穿连接件的筒壁;筒体与不锈钢密封环的焊接接头在电偶腐蚀、缝隙腐蚀、应力集中的综合作用下发生严重断裂,裂纹周向长度约为1/4圆周。此外,服役2000 h后GH4169合金筒体的力学性能良好,强度损失程度较小。
Microstructures and mechanical properties of GH4169 alloy cylinder and its weld joints in a supercritical water reactor are studied after operating 2000 h.The results show that the GH4169 alloy cylinder exhibits good corrosion resistance under conditions of high temperature,high pressure,and sucrose mixed solution;the thickness loss rate of the cylinder is 0.005-0.255μm/h;the corrosion products primarily consist of oxides and phosphates.However,the welded joints connecting the cylinder and other components represent a vulnerable point that significantly impacts the remaining lifespan of the reactor.The calculated crack propagation rate of the GH4169 alloy cylinder is 5.25μm/h,indicating that it would only take 762 h for the crack to penetrate through the wall of the connector.Additionally,severe fracture occurs(the circumferential length of the crack is approximately 1/4 of the circumference)at the weld joint between cylinder and stainless-steel,resulting from the synergistic effects of galvanic corrosion,crevice corrosion,and concentrated stress.Despite these challenges,the strength loss of the cylinder is relatively small,which means that the cylinder maintains satisfactory mechanical properties.
作者
刘刈
朱成
班子惠
李应举
冯亚鑫
张振涛
杨院生
LIU Yi;ZHU Cheng;BAN Zihui;LI Yingju;FENG Yaxin;ZHANG Zhentao;YANG Yuansheng(China Institute of Atomic Energy,Beijing 102413,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《材料工程》
北大核心
2025年第11期63-71,共9页
Journal of Materials Engineering
基金
辽宁省应用基础研究计划项目(2023JH2/101300142)
国家自然科学基金核技术创新联合基金(U226720033)。
关键词
超临界水氧化
GH4169合金
腐蚀速率
应力腐蚀开裂
supercritical water oxidation
GH4169 superalloy
corrosion rate
stress corrosion cracking
