COMPOSITE PIPE CONSISTING OF BEARING PIPE AND AT LEAST ONE PROTECTIVE TUBE, AND METHOD OF ITS PRODUCTION Russian patent published in 2019 - IPC F16L9/18 B32B15/01 B32B1/08 F16L58/08 C22C38/04 C22C38/08 C22C38/06 C22C38/18 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of clad tubes and relates to composite pipe and method of its production. Pipe consists of a bearing pipe and at least one protective tube, at that the bearing pipe is made out of non-corrosive steel, having at least partially an austenite structure, with the following chemical composition (wt%): C: from 0.005 to 1.4; Mn: from 5 to 35; iron – the rest, including obligatory elements of steel, with addition of the following optional elements (wt%): Ni: from 0 to 6; Cr: from 0 to 9; Al: from 0 to 15; Si: from 0 to 8; Mo: from 0 to 3; Cu: from 0 to 4; V: from 0 to 2; Nb: 0 to 2; Ti: from 0 to 2; Sb: 0 to 0.5; B: 0 to 0.5; Co: from 0 to 5; W: from 0 to 3; Zr: from 0 to 4; Ca: from 0 to 0.1; P: from 0 to 0.6; S: from 0 to 0.2; N: from 0.002 to 0.3. Invention also relates to a method of producing a composite pipe consisting of a bearing pipe and at least one protective tube mechanically or metallurgically connected to each other.

EFFECT: invention provides improved manufacturability of composite pipe intended for use in corrosive medium.

30 cl, 3 dwg