THICK-WALLED FINE DIAMETER FUEL INJECTION PIPE AND ITS MANUFACTURE

摘要

(A) A thick-walled small composite metal tube for fuel injection consists of an outer carbon steel tube and an inner stainless steel tube press-fitted together by drawing and metallurgically bonded together, the inner wall surface of the inner tube having a diffusion layer of metal(s) selected from Ni, Cr, Mo, Co, Al, Cu and their alloys. (B) Prodn. of the tube comprises (a) press bonding an inner stainless steel tube and an outer carbon steel tube by drawing, the inner tube having a coating of Ni, Cr, Mo, Co, Al, Cu or their alloys; and (b) heating the press bonded tubes in vacuum or non-oxidising atmos. to produce a diffusion bond between the adjoining tube surfaces and a diffusion layer of the metal or alloy on the inner wall surface of the inner tube.