The investigation of microstructure and mechanical properties of high chromium white cast iron / AISI 1040 steel couple welded by friction welding method

Basically, welding processes are divided into two groups as solid-state welding and fusion welding. In the fusion welding technique, there is a full melting in the weld interface while there is a partial melting in the solid-state welding technique. The traditional melting welding methods for joining metals are sometimes unsuitable due to the formation of brittle and low melting metals, metallurgical incompatibility, large differences in melting points, and thermal mismatch. Friction welding which is a solid-state joining process is one of the most effective processes for joining similar and dissimilar materials. In this method, the combination of materials is achieved by the combined effects of the pressure and relative movement of the two workpieces, by heating the connection weld interface and by plastic deformation of the material. It is widely used in the automotive and aerospace industrial applications. The thesis consists of three parts; in the first part, a literature searches on the subject are given. In the second part, experimental studies are presented in detail. In the third part, experimental results are given. In this study; AISI1040 steel and high chromium white cast iron were welded with friction welding method by using different rotational speeds. Structural changes in the weld interface were examined by Optical Microscope (OM), Scanning Electron Microscope (SEM), Energy Distribution Spectrometer (EDS), X-Ray Diffraction (XRD) and microhardness analysis. In addition, tensile tests were performed to determine the mechanical strength of welded joints. Fracture surface morphology was analyzed by SEM, EDS and mapping.