T22/TP304H带垫板异种钢焊接接头显微组织与力学性能分析
Analysis on Microstructure and Mechanical Properties of T22/TP304H Dissimilar Steel Welded Joint with Backing Plate
汪峰 1李梁 2徐刚 1张赵斐 1李飞 1徐敏1
作者信息
- 1. 华能国际电力股份有限公司南通电厂,江苏 南通 226003
- 2. 西安热工研究院有限公司,陕西 西安 710054
- 折叠
摘要
异种钢焊接接头在火电厂锅炉结构中被广泛应用,对存在裂纹的现服役接头进行分析是评价异种钢焊接接头安全问题的基础.借助金相显微镜和扫描电镜对某含裂纹的T22/TP304H带垫板异种钢焊接接头进行了组织形貌分析,焊接材料为镍基合金,并利用显微硬度计和万能拉伸试验机分别对接头进行了显微硬度测试及拉伸性能测试.结果表明:焊缝的显微组织主要为奥氏体、Nb(C,N)析出相和M23C6 碳化物;T22 侧熔合区存在明显的细晶强化作用,该区域硬度增大,TP304H侧熔合区奥氏体晶粒粗化现象不明显;接头的常温和高温拉伸性能存在明显的劣化情况.
Abstract
Dissimilar steel welded joints are widely used in the boiler structure of thermal power plants,and the analysis of the joints containing cracks in service is the basis to evaluate the safety of dissimilar steel welded joints.With the help of metallurgical microscopy and scanning electron microscopy,the morphology of a T22/TP304H dissimilar steel welded joint with backing plate containing cracks was analyzed,and the welding material was nickel based alloy.The microhardness tester and universal tensile testing machine were used to test the microhardness and tensile properties of the welded joint respectively.The results show that the microstructure of the weld is mainly austenite,Nb(C,N)precipitation phase and M23C6 carbides.There is an obvious fine grain strengthening effect at the fusion zone of T22 side,and the hardness value of the region increases.Austenite grain coarsening phenomenon is not obvious at the fusion zone of TP304H side.There is a significant deterioration of tensile properties of the welded joint at room temperature and high temperature.
关键词
T22/TP304H异种钢/熔合区/显微硬度/力学性能Key words
T22/TP304H dissimilar steel/fusion zone/microhardness/mechanical properties引用本文复制引用
基金项目
中国华能集团有限公司研究项目(HNKJ20-G01)
出版年
2024
NETL
NSTL
万方数据