Study on Mechanism of Friction Welding in Carbon Steels

This report deals with the bonding mechanism in friction welding. The structure and the temperature are investigated near the bonding interface of S15C (JIS G 4051) steels, using a machine built as a trial. The following results are obtained. The process of friction welding is characterized by three phases ; generating of frictional heat, up-setting and bonding. There is a transition zone near the center of the weld. The temperature is measured by the following three methods : metallurgical observations, numerical calculations and measurements by thermocouples. According to these results, the temperature at the rubbing surface increase about 1300℃, but remains lower than the melting point. Within the limits of this experiment, it is assumed that the mechanism of friction welding is considered primarily a mechanical mixing in the transient zone in solid state.