A METHOD FOR MANUFACTURING A BIMETALLIC LONG-LENGTH CYLINDRICAL PRODUCT OF THE TYPE OF STEEL PIPES AND A BIMETALLIC PRODUCT MADE BY THIS METHOD Russian patent published in 2023 - IPC B23K20/02 B23K101/06 B32B15/01 

FIELD: manufacturing of bimetallic pipes.

SUBSTANCE: The invention can be used in the manufacture of bimetallic pipes, in particular plunger pump housings used in conditions of exposure to aggressive media in the oil industry. The surfaces of a thin-walled pipe made of corrosion-resistant steel are pretreated to obtain a rough outer surface and a polished inner surface with subsequent nitriding. The workpiece is placed in a thick-walled steel shell with a gap and connected along the mating surfaces by deformation by radial forging. Nitriding is performed by the ion-plasma method in a dissociated ammonia at low temperature heating of 480 ± 10 °C with the achievement of hardness of each of the surfaces of a thin-walled workpiece within 1000-1100 HV. Deformation by radial forging is carried out with the introduction of a rough surface of a thin-walled workpiece into the inner surface of a thick-walled shell with a degree of deformation of no more than 6% to obtain a composite layer.

EFFECT: The present invention enables to produce a composite through the optimization of nitriding and plastic radial forging that simultaneously ensures the corrosion resistance and wear resistance of the surface, significantly increasing the service life of a bimetallic product.

3 cl, 5 dwg, 1 tbl