METHOD OF MAKING LAMINATE METALLIC TUBES Russian patent published in 1995 - IPC

FIELD: tube production. SUBSTANCE: method comprises steps of making a metallic strip by rolling, directly after the strip had been rolled, measure cutting it and upon winding the measure cut strip on a formate drum applying on it an easy meltable metal in the form of powder or a sheet with melting temperature no more, than 1100 C at temperature value of the steel strip less, than the above mentioned melting temperature of the easy meltable metal. In order to simplify an assembling procedure, to isolate the tube from action of gases and liquids and from corrosion, the metallic sheet is being wound on a hollow metallic core, being monolithic or of one sheet, having in its outer surface a shoulder with a height , equal to a thickness of the metallic sheet, and with a length, equal to a width of the measure cut blank, in such a way, that an end of the material to be wound is placed in a butt with the shoulder. An outer surface of the core is helical one due to a wound layer of high-strength metallic sheet. Upon cooling the laminate metallic tube its outer layers (due to their linear narrowing) force inner layers with a high effort, increasing diffusion of the assy meltable metal into layers of the rolled metallic sheet with preliminary stress of layers of the tube. EFFECT: enlarged using range. 2 cl, 3 dwg