压力容器2025，Vol.42Issue(1)：1-9,9.DOI:10.3969/j.issn.1001-4837.2025.01.001
TT自动焊在X7Ni9钢制LNG储罐内罐环焊缝焊接上的应用研究
Application of TT automatic welding in circumferential seam welding of X7Ni9 steel LNG storage tank inner vessels
摘要
Abstract
To improve the welding quality of circumferential seams in LNG storage tank inner vessels,this study focuses on the tandem TIG welding process for X7Ni9 steel circumferential seams.A double-J narrow groove design and single-sided welding with double-sided formation technology were applied to investigate the mechanism behind the excellent cryogenic toughness of tandem TIG welded joints.Microstructure analysis was performed using optical microscopy and scanning electron microscopy.Non-destructive testing and mechanical evaluations,including tensile,bending,impact,hardness,crack tip opening displacement,and X-ray diffraction tests,were conducted.Results showed that the welds exhibited excellent formation and performance.The average tensile strength reached 743 MPa,and bending tests confirmed defect-free welds.At the temperature of-196 ℃,the impact toughness values were 152.1 J for the upper weld surface with a lateral expansion of 1.82 mm,164.2 J for the root weld with 1.58 mm lateral expansion,233.1 J for the upper heat-affected zone with 2.05 mm lateral expansion,and 175.3 J for the root heat-affected zone with 1.71 mm lateral expansion.The crack tip opening displacement values were 0.465 mm for the weld and 0.734 mm for the heat-affected zone,demonstrating outstanding cryogenic toughness.This is attributed to the fine-grained austenitic microstructure,high purity,and abundant reversed austenite content in the weld.The developed tandem TIG welding process has been successfully applied in engineering demonstrations,providing a foundation for its broader use in LNG storage tank manufacturing.关键词
LNG储罐/TT焊/组织性能/低温韧性Key words
LNG storage tank/tandem TIG(TT)welding/microstructure and properties/cryogenic toughness分类
机械工程引用本文复制引用
周聪,路兴才,赵龙一,谌康..TT自动焊在X7Ni9钢制LNG储罐内罐环焊缝焊接上的应用研究[J].压力容器,2025,42(1):1-9,9.基金项目
国家管网集团课题(GWHT20220034157BG1) （GWHT20220034157BG1）
