TUBULAR COMPOSITION MATERIAL Russian patent published in 1999 - IPC

FIELD: manufacture of articles containing metallic portions, for example by rolling, powder metallurgy, extrusion or welding including explosion welding process, possibly for making structures in building, machine engineering and other industry branches. SUBSTANCE: tubular composition material includes in cross section at least two subareas of materials. At least a part of line of cross section boundary and(or) at least a part of line of material subareas boundary is in the form of fragment of oblique cone section of straight round cone. It provides constructionally involved thickness change at least of one subarea of tubular composition material at shaping operations due to use of fragments of oblique cone section of straight round cone with possibility of their mutual confluence. EFFECT: enhanced technological effectiveness and lowered material consumption of articles of tubular composition material due to use of combination of fragments of oblique cone sections of straight round cone. 16 cl, 16 dwg