摘要
Abstract
This study systematically investigates the microstructure evolution and mechanical properties of T4003 ferritic stainless steel joints fabricated by laser wire filling welding and metal active gas welding(MAG).Welding experiments were conducted using butt joint configurations,and the microstructure,hardness distribution,tensile properties,and fracture mor-phology were characterized via optical microscopy,Vickers microhardness testing,tensile testing,and scanning electron mi-croscopy(SEM).Results indicate that the LWFW joint exhibits a dual-phase microstructure(austenite+ferrite)in the weld zone,with an average hardness of 338 HV,significantly higher than that of MAG joints(251 HV).The tensile strength of LWFW joints(548 MPa)exceeds that of MAG joints(469 MPa)by 16.4%.The MAG joint shows the highest hardness(299 HV)near the fusion line,with pronounced hardness fluctuations in the heat-affected zone(HAZ),and demonstrates superior elongation(12.0%)compared to laser wire filling welding(8.95%).Both joints fractured in the HAZ during tensile testing and exhibited excellent bending resistance without cracking.Fractographic analysis reveals ductile fracture characteristics with dimple aggregation for both methods,while MAG joints display larger and deeper dimples,indicating enhanced plastic deformation capability.This study provides critical insights into the selection of welding processes for low-nickel ferritic stainless steel in industrial applications.关键词
铁素体不锈钢/激光填丝焊接/微观组织/力学性能Key words
ferritic stainless steel/laser wire filling welding/microstructure/mechanical property分类
矿业与冶金
