压力容器2025，Vol.42Issue(3)：11-19,9.DOI:10.3969/j.issn.1001-4837.2025.03.002
7Ni钢GTAW焊接接头组织与性能研究
Research on the microstructure and properties of GTAW welded joints for 7Ni steel
摘要
Abstract
To address the critical welding issues for the engineering application of 7Ni steel,gas tungsten arc welding(GTAW)was employed using ⌀2.4 mm ERNiCrMo-4 welding wire in the flat position to weld 10 mm thick 7Ni steel plates.The microstructure of the welded joint was observed by optical microscopy and scanning electron microscopy,and the performance of the welded joint was evaluated through tensile,impact,bending,and hardness tests.Results show that the GTAW welded joint of 7Ni steel exhibited good fusion,with no welding defects such as cracks or pores detected by visual and non-destructive inspection.The weld zone primarily consisted of columnar and dendritic austenite with precipitates,showing the lowest hardness;the heat-affected zone mainly contained lath martensite,exhibiting the highest hardness.The tensile strength of the welded joint reached 794 MPa.The average impact absorption energy of the weld zone and heat-affected zone was 102.3 J and 118.7 J,respectively,with lateral expansion values of 1.23 mm and 1.31 mm,indicating excellent impact performance.Side bend tests met acceptance criteria,demonstrating that GTAW is a suitable method for welding 7Ni steel.This study provides references for formulating welding procedures for 7Ni steel.关键词
LNG储罐/7Ni钢/钨极氩弧焊/显微组织/力学性能Key words
LNG storage tank/7Ni steel/gas tungsten arc welding(GTAW)/microstructure/mechanical properties分类
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张卫斌,邹妮康,杨凯,刘江,郭佳伟,席连云,赵瑞辉,徐晶晶,石凤健..7Ni钢GTAW焊接接头组织与性能研究[J].压力容器,2025,42(3):11-19,9.基金项目
国家自然科学基金项目(52275339) （52275339）
江苏省特种设备安全监督检验研究院科技计划项目[KJ(Y)202423] （Y）
