Friction welding of ductile iron with stainless steel

The study of mechanical properties and microstructure of friction welded coupe of ductile iron with stainless steel are presented. Scanning electron microscopy (SEM) was used for investigation of the fracture morphology and phase transformations taking place during friction welding process. It was concluded that in case of bainitic ductile iron (BDI) the fracture precedes mainly trough the cleavage planes. Moreover, the distribution of selected elements on both side of the joining interface was studied using EDS line and maps spectrometry. The EDS spectrometry showed some enrichment of ductile iron with Cr and Ni atoms close to the joint. The depth of Cr atoms penetration reached 50 μm. The heat generated locally by friction increased the temperature in the area close to the interface even over the melting point of ductile iron. This was confirmed by metallography which revealed the carbide eutectic enriched with Cr in ductile iron.

► The results of the mechanical and SEM study of the friction welding of ductile iron with stainless steel are presented.
► The results of the EDS-analysis shows that the intensity of diffusion processes during friction welding of bainitic ductile iron (BDI) is larger than ferritic ductile iron (FDI).
► The SEM–EDS spectrometry showed also some enrichment of ductile iron with Cr and Ni atoms close to the joint.
► The range of Cr and Ni diffusion in iron generally does not exceed 50 μm.