摘要
对控制棒驱动机构密封焊接件不同区域(基体金属BM、基体金属的热影响区HAZbm、熔合区域、焊缝金属的热影响区HAZwm和焊缝金属WM)的微观结构、显微硬度和电化学性能进行了研究。试验结果表明,在熔合线两侧分别观察到包含Σ3、Σ9孪晶晶界的等轴晶和Σ5、Σ7晶界的柱状晶粒分布。焊缝区的凝固模式为铁素体-奥氏体(FA)模式,其中,铁素体包括3种形态(HAZwm内为骨架状铁素体,在WM内为板条和多边形状铁素体)。晶粒尺寸和铁素体体积分数的变化导致焊接件的硬度从基体金属到焊缝金属不断增加。与焊缝金属和融合区域相比,在3. 5%氯化钠溶液和核电模拟溶液中基体金属具有更高的自腐蚀电位。
Microstructures,microhardness and electrochemical properties at different zones of the weld joint(base metal-BM,heat affected zone near base metal-HAZbm,fusion boundary-FB,heat affected zone near weld metal-HAZwm,and weld metal-WM)in the canopy seal welds of control rod drive mechanism are investigated.The results indicate that compound twins in equiaxed grains withΣ3andΣ9boundaries and columnar grains withΣ5andΣ7boundaries are observed on two sides of FB,respectively.The weld zone is solidified as ferrite-austenite(FA)mode and consists of three kinds of ferrites(skeleton ferrite in HAZwm,lath and polygon ferrites in WM).Microhardness continuously increases across the FB from BM to WM due to the change of grain size and ferrite volume fraction.The WM and fusion zone(from HAZbm to HAZwm)are shown more electrochemical active than the BM in either3.5%NaCl solution or nuclear power simulated solution.
作者
胡娟
王徐颖
王玮
陆永浩
Hu Juan;Wang Xuying;Wang Wei;Lu Yonghao(State Power Investigation Corporation Limited, Beijing 100033, China;National Center for Materials Service Safety, University of Science and Technology Beijing,Beijing 100083, China)
出处
《工程与试验》
2018年第4期34-40,71,共8页
Engineering and Test
基金
国家重点研究发展计划(2016YFF0203804)
关键词
焊接件
不锈钢
显微结构
显微硬度
电化学性能
weld joint
stainless steel
microstructure
microhardness
electrochemical property
作者简介
胡娟(1971-),女,高级工程师,研究方向为核电材料的性能评价。
