FORMATION OF PROJECTION ON OUTSIDE SURFACE OF HEAT TRANSMISSION PIPE

摘要

PURPOSE:To form a build-up part having high density and high adhesiveness with excellent workability in the stage of forming the build-up part for preventing the deterioration of corrosion resistance on the outside surface of the part to be supported of a heat transmission pipe of a heat exchanger by thermally spraying a specific material to the surface then impregnating solder therein. CONSTITUTION:Ni or ZrO2 is thermally sprayed to the part 6a to be supported in part of a thin-walled and long-sized heat transmission pipe 6 of the heat exchanger, if the heat transmission pipe material is an Fe-Ni-Cr alloy, to form the build-up part 9 and to form the part to be supported in order to support the part to be supported of said transmission pipe to a pipe supporting part. After the thermally sprayed build-up part is shaped by grinding or polishing, adequate solder is used and is heated to the temp. near the annealing temp. of the heat transmission pipe so as to form brazing parts 10 in the build-up part and to impregnate the solder into small holes in the thermally sprayed build-up part. Since the thermally sprayed porous build-up part is impregnated by the solder, the projection parts to be supported of the heat transmission pipe having the excellent corrosion resistance are formed by the simple method. The thermally spraying material may be thermally sprayed and built up after the solder 10 is preliminarily mounted to the part to be supported of the heat transmission pipe.