METHOD FOR MAKING BIMETALLIC CYLINDRICAL PRODUCTS SICH AS TUBES Russian patent published in 2001 - IPC

FIELD: techniques for making bimetallic cylindrical products with inner clad coating. SUBSTANCE: method comprises steps of placing with gap inside envelope blank of coating material in the form of single layer along the whole length or in the form of multistrand helix; performing plastic deformation of blank by radial forging at simultaneous outer cooling of it at deformation degree 5-90% until joining envelope and blank along contact surfaces; using as blank sheet material made of plastic antifriction and(or) corrosion resistant metal or its alloy. Method provides enhanced operational reliability of products made of bimetallic tubes due to increased rigidity and strength of construction, strict rectilinearity of tube inner surface and stable thickness of inner coating layer along its whole length, lowered thickness of that layer and its improved strength. EFFECT: enhanced efficiency of method and improved operational reliability of products. 3 cl, 1 ex