304奥氏体不锈钢A-TIG焊接头组织与力学性能研究

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中图分类号：UG405 文献标志码：B doi：10.20214/j.cnki.zhgdjt.2025.06.013

Abstract：This study employed an activated flux composition of 63%SiO2+6%MnO2+16%Cr2O3+ 15% （204 Al2O3 for A-TIG welding of 304 austenitic stainless steel. The microstructure and mechanical properties of weld joints were systematically characterized through macroscopic metallography，scanning electron microscopy（SEM）， energy-dispersive X-ray spectroscopy（EDS）， tensile testing，and hardness measurements. The results demonstrate that compared to conventional TIG welding，A-TIG welding achieves complete joint penetrationand produces defect-free stainless steel weld joints. The fusion zone primarily consists of distinct columnar dendritic crystals growing perpendicular to the fusion boundary. EDS area and line-scan analyses reveal homogeneous elementaldistribution across both the fusion zone and heat-afected zone （HAZ），with no significant chemical transition regions observed，indicating absence of elemental segregation at the fusion line/HAZ interface.Furthermore，the tensile properties of A-TIG welded joints closely match those of the base metal，exhibiting an optimal strength-toughness balance，which confirmsexcellent mechanical performance of the joints. This study establishes a foundation for optimizing A-TIG welding processes and tailoring microstructure-mechanical property relationships in A-TIG welded joints.

Key words：304 austenitic stainless steel；A-TIG；weld joint；microstructure；mechanical properties

不锈钢因具有耐腐蚀性强、强度高及塑性好等优点，被广泛应用于轨道交通、航空航天及核电装备等领域[1-3]。（剩余5713字）