Structural, Chemical and Deformation Changes in Friction Welded Joint of Dissimilar Steels

N. Ratković, Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia. R. Nikolić, Faculty of Civil Engineering, University of Žilina, Žilina, Slovakia. I. Samardžić, University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Croatia. Fundamental principles of friction welding of dissimilar steels (high speed and tempering steel) from the aspect of metallurgical and chemical processes occurring in the joint zone are presented in this paper. Considering that phenomena accompanying the friction welding are interdependent, it was necessary to experimentally determine the process variable parameters, to establish the optimal welding regime. The experiments were set and realized so that all the variables were analyzed as a function of the friction time. The metallographic investigations included analysis of the joint zone microstructure through structural phases and hardness changes, due to influence of the heat treatment annealing. The experimental work included analysis of the geometry changes, the joint zone structure and the basic mechanical characteristics of the joint realized by the friction welding.