Fatigue strength of austempered ductile iron-to-steel dissimilar arc-welded joints

Abstract Nowadays, the use of different classes materials in same structure is increased to keep pace with innovation and high structural performances. In this context, components made need be joined together a possible solution given by arc welding. Dissimilar welded joints must often able withstand fatigue loads; however, Design Standards provide strength categories only for homogeneous joints. The aim present paper compare behaviour EN-GJS-1050 austempered ductile iron-to-S355J2 steel dissimilar corresponding joints, as suggested International Recommendations. For purpose, experimental tests were performed on selection details. First, microstructure was identified metallographic analysis; micro-hardness measurements collected residual stress profiles obtained using X-ray diffraction technique Misalignments quantified all specimens. Then, have been number joint geometries subject axial or bending loadings tested as-welded conditions. fracture surfaces analysed locate crack nucleation sites.