Investigations on Joining Surface Hardened Steels by Friction Welding

Abstract

Abstract The particularities of joining surface hardened steels (carburized, nitrided and induction hardened) using friction welding are analyzed in order to assess the influence of the wear protection layers on the welding process. The joint influence of the friction speed, friction pressure and time, as well as the upsetting pressure is evaluated for joints made out of carburized, nitrided and carburized with nitrided steels, respectively. The investigation of microstructure and properties allows an optimization of the friction welding parameters. The friction stroke appears to be the main parameter for welding carburized and nitrided steels, respectively. For welding carburized with nitrided parts, remains of carbon and nitrogen enriched materials are still present in the joining plane, regardless of the axial pressure and the friction stroke. Only a limited diffusion of the two components in the axial direction can be detected.