焊后热处理对CAP1400蒸发器压力边界焊缝不锈钢隔离层组织和性能的影响  

Effect of postweld heat treatment on microstructure and properties of stainless steel surfacing layer of CAP1400 evaporator pressure boundary weld

作　　者：薛小怀[1] 李郅远 王志颖 李天宇 杨巨文 张文杨 张茂龙 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]上海电气核电设备有限公司,上海201306

出　　处：《材料热处理学报》2018年第2期108-112,共5页Transactions of Materials and Heat Treatment

基　　金：科技部重大专项(2014ZX06002-001)

摘　　要：通过金相试验、拉伸试验和硬度试验,研究了焊后热处理对CAP1400蒸发器压力边界焊接接头不锈钢隔离层组织和性能的影响。结果表明：在多层多道焊热循环的作用下,不锈钢隔离层焊缝金属发生了再结晶,再结晶晶粒长大形成粗大的柱状奥氏体组织;焊后热处理保温时间对不锈钢隔离层焊缝金属的屈服强度影响不大,随着保温时间的增加,抗拉强度先增加后减少;保温温度对不锈钢隔离层强度和塑性的影响不显著。虽然压力边界接头的断裂方式为塑性断裂,但是不锈钢隔离层是整个接头的薄弱环节。当保温时间40～40.5 h,保温温度615～620℃时可获得综合性能优良的接头。Effects of postweld heat treatment on microstructure and properties of stainless steel surfacing layer of CAP1400 evaporator pressure boundary weld were studied by means of metallographic,tensile and hardness tests. The results show that the recrystallization occurs in the stainless steel surfacing layer during multi-pass and multi-layer welding,then the coarsening columnar structure forms from the recrystallized austenitic grain. The holding time after postweld heat treatment has little effect on the yield strength of the stainless steel surfacing layer. The tensile strength increases first then decreases with the increasing of the holding time. The holding temperature has little influence on the strength and plasticity of the stainless steel surfacing layer. The fracture mode of the pressure boundary joint is plastic fracture and the stainless steel surfacing layer is the weak link of the whole joint. The pressure boundary joint with excellent comprehensive performance can be obtained after holding at 615-620 ℃ for 40-40. 5 h.

关 键 词：CAP1400蒸发器 压力边界 不锈钢隔离层 焊后热处理 

分 类 号：TG445[金属学及工艺—焊接]