Analysis of carbon and carbide phases distribution in friction welded joints

Abstract

Investigation and analysis of the phenomena during rotational friction welding process of the high speed steel M2 (AISI SAE) with quench and tempered carbon steel 1060 (AISI SAE) are presented. Welding parameters as time and friction pressure are varied in experiments. Also different post weld heat treatment (PWHT) regimes, as annealing and quenching are applied. Distribution of the carbon and carbide phases in period of friction during the process of rotation friction welding process and after PWHT and effects on weld quality are analysed. Investigations are performed by the classical and quantitative optical microscopy. Displacement and distribution of carbides in the high speed steel during friction period in viscous layer, than in friction plane and surrounding zones are studied. Results of the quantitative optical microscopy are showed distinct difference of the carbide phase ratio in investigated zones. Obtained results are verified by the EDS analysis of characteristic zones close to the friction plane. Results of the SEM analysis are shown difference in the carbide phase quantity close to the friction plane as a result of the metal flow in viscous layer and in the viscous - plastic zones, with presence of hard carbide particles, and also of the carbide phase dissolution. Beside optical microscopy investigations, effects of the welding parameters and PWHT on carbon and carbide distribution are analysed by the measuring of the micro hardness and mechanical properties which are tested in friction plane. Obtained results have shown direct dependence between welding parameters and applied PWHT on the properties and quality of the friction welded joints.