METHOD FOR MAKING BIMETALLIC ELONGATED CYLINDRICAL ARTICLES SUCH AS TUBES Russian patent published in 2005 - IPC

FIELD: manufacture of bimetallic elongated cylindrical articles operating in condition of action of aggressive medium with large content of abrasive.

SUBSTANCE: method comprises steps of placing blank of anticorrosion and(or) anti-friction material with gap inside steel envelope along the whole length of envelope; joining blank and envelope along their adjoined surfaces due to cold deforming of them by radial forging on mandrel at deformation degree 3 - 50% and supplying liquid lubricant to deformation zone; simultaneously cooling envelope outside; after joining realizing surface hardening of inner working surface by low-temperature chrome plating due to continuously pumping chrome -containing electrolyte. Cylindrical anode mounted along axis of article along its whole length is used. Current supply terminals are uniformly arranged on outer surface of envelope. Then chrome plated surface is subjected to finishing.

EFFECT: manufacture of precision bimetallic articles characterized by good operation reliability in condition of aggressive medium action for long time period.

6 cl, 1 ex