Parameter influence on friction welding of dissimilar surface-carburized/volume-hardened alloyed steels

The influence of the main friction-welding parameters, such as the axial pressure, the friction stroke and the upsetting temperature on the compositional, structural and hardness gradient is shown for dissimilar joints made out of carburized and volume-hardened steels. The expulsion of the carbon-enriched layer in the burr as a qualitative factor is analyzed. Low axial pressure and long friction time favours to the presence of a carburized layer in the joint plane. A high axial pressure, as well as an increase in the friction stroke favours the expulsion of the carbon-enriched layer from the joining area into the burr. A high upsetting pressure leads to an increase of the plasticized material expulsion in the burr.