PIPE SOLDERING METHOD Russian patent published in 2000 - IPC

FIELD: mechanical engineering; brazing and soldering. SUBSTANCE: proposed method can be used in making from heterogeneous materials differing in thermal expansion coefficient. Mainly from tantalum or niobium and stainless steel designed for operation in aggressive media. Surface to be soldered are made conical. Layer of copper, thickness 20 - 25 μm is applied to tantalum or niobium pipe surface. After thermal treatment under vacuum, layer of copper, thickness up 1 mm, is applied. When soldering stainless steel pipe, layer of nickel, 10-15 μm thick, is applied to surface to be soldered. Parts are butt-joined with interference fit to cone. Solder is applied from of tantalum or niobium pipe. Soldering is carried out in vacuum of 1•10^-4 mmHg. Cooling is done in vacuum and then in the air. Assembly units, thus formed, operate reliably at temperature up to 2000 C in aggressive media. EFFECT: provision of high tightness and strength of soldered joints. 4 cl, 2 ex