The microstructure and mass transport during friction welding of ductile cast iron

Abstract

PurposeThe results of a study of friction welding of ductile cast iron using stainless steel interlayer are presented. Based on the microstructure evolution at the region close to the ductile cast iron‐stainless steel interface, the phenomena accompanying the process of joining were evaluated. Therefore, the purpose of this paper is to take a closer look into metallurgical phenomena accompanying the friction welding of ductile cast iron.Design/methodology/approachIn this paper, ductile cast iron and austenitic‐stainless steel are welded using the friction welding method. The tensile strength of the joints was determined using a conventional tensile test machine. Moreover, the hardness across the interface ductile cast iron‐stainless steel interface was measured on a metallographic specimen. The microstructure of the joints was examined using light metallography as well as electron microscopy. In this case, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied. Energy Dispersive X‐ray analysis (EDS) was carried out across the section of friction welded ductile iron‐stainless steel interface.FindingsOn the basis of careful analysis of experimental data it was concluded that the process of friction welding was accompanied with diffusion of Cr, Ni and C atoms across the ductile cast iron‐stainless steel interface. This leads to an increase of carbon concentration in stainless steel where chromium carbides were formed, the size and distribution of which was dependent on the distance from the interface.Originality/valueThe main value of this paper is to contribute to the literature on friction welding of ductile cast iron.