Pressure bonding bodies made of metallic material - e.g. steel pipes for boilers, using super plastic phenomena

摘要

In bonding bodies of metallic materials pressure is applied to the abutting surfaces to be bonded and simultaneously with the application of pressure the material near the bond is alternately heated and cooled to above and below the transformation temp (s). until a permanent bond is formed. The bodies are subjected to a triangular waveform temp. cycle and to a light mechanical load so that the pressure bonding is performed by making use of superplastic phenomena. In bonding steel pipes for use in boilers, e.g. where they may be exposed to sulphur atmos. and also in bonding cast iron, aluminium alloy etc. The light load may be applied without applying any external force for mechanical loading. The working time may be shortened to less than 5 mins. As the heating temp. is far lower than the m.pt. of e.g. steel there is no change in the metallurgical structure.