Microstructure and Properties of TIG Welded Joint of Hot Rolled 410S Stainless Steel Plates

The microstructure and properties of TIG welded joint of hot rolled 410S stainless steel plates were studied by using metallographic microscopy,nondestructive examination (NDE),mechanical property testing and Huey test,ferrite content and microhardness measuraments.The results show that the tensile strength of TIG welded joint was not less than that of base-metals,and the ductility was fine.The macrograph of the weld joint exhibited coarse structure with epitaxial growth characteristic.Microstructure of weld joint was composed of columnar austenic grains and ferrite along the austenite.The ferrite volume fraction was 15%-20%.Martensite phase in HAZ created M→γ→M,fine particle martensite at grain boundaries was converted into black block martensite.The intergranular corrosion trend of the joint was HAZ ＞ base material ＞ weld seam.