Sensitization of Braze-Pressure Welding of Stainless Steel

Japanese Ministry of Land, Infrastructure, Transport and Tourism offers to build, so they called, the 100 years endurable house and building. Those buildings are expected to extend their lifetime and to reduce the consumption of resources for re-building. The lifetime extension of structures or skeletons of building has already accomplished. But the ordinary steel piping inside of the building withstands against the corrosion for 20 – 30 years. Therefore the stainless steel piping is expected to be installed into those long lifetime buildings. In this research, the braze-pressure welding is allied to the stainless steel pipe joining. The braze-pressure welding (BPW) is a mixed method of brazing and pressure welding. By the insertion of the low melting point brazing filler alloy, the joining interface is made clean without the oxides. It allows the following pressure welding process to join the interface without high pressure. For the BPW joint, the EPR test was conducted to measure the degree of the sensitization of stainless steel. By modifying the thermal history, the BPW joint without sensitization was obtained.