Optimization of Fusion Penetration Process and Microstructure Analysis of Austenitic Stainless Steel Double T-shaped Joints
An efficient FCAW welding method was adopted for the penetration process of double T-shaped joints in aus-tenitic stainless steel plates which replaced SMAW.Based on X-ray inspection,macroscopic morphology,and microscopic metallographic analysis,the internal quality and microstructure evolution of the joints were studied.The experimental re-sults indicated that incomplete fusion and penetration of the root weld,interlayer slag inclusion,and porosity were the most frequent internal quality defects in double T joints.Through experimental verification,it has been found that appropriate groove forms and weld layer thickness could obtain double T-shaped welded joints with excellent internal quality;the micro-structure of the base metal zone of the welded joint was equiaxed austenite and a small amount of high-temperature residual hot rolled material 8 ferrite structure.The microstructure of the heat affected zone of the welded joint was a small amount of 8 Ferrite precipitation along the austenite grain boundaries,the most complex tissue evolution was in this region,and it was divided into zone Ⅰ,zone Ⅱ,and zone Ⅲ.The weld zone of the welded joint was in the form of lath δ ferrite and the micro-structure of ferrite and austenite distributed along the solidification boundary.It could be inferred from its morphology that the solidification mode of the weld zone was FA mode.
NETL
NSTL
万方数据
