Fatigue and microstructure of welded joints of metal sheets for automotive exhaust system

Abstract Fillet or butt welded joints were prepared, so that the sheets of low carbon or stainless steels such as 18Cr–1Mo–Ti were welded by MIG or TIG method with the ferritic or austenitic welding wires, followed with or without heat treatment. The geometry of deposited zone, element distribution, crystal structure, microstructure, stress and fatigue of the joints, was tested with the tensile and fatigue tests, EPMA composition analysis, X-ray diffraction, microscopic examination, computer simulation etc.