METHOD OF PROCESS PIPES PRODUCTION OF SIZE 284×11 mm OUT OF SOLID BLANK INGOTS TO MANUFACTURE HEX BLANK PIPES WITH TURNKEY SIZE 252,6×5,0+1,5/-1,0×4300+80/-30 mm FOR TIGHT STORAGE AND TRANSPORTATION OF SPENT NUCLEAR FUEL

FIELD: metallurgy.SUBSTANCE: invention relates to pipes production, in particular to method of process pipes production of size 284×11×26100-26600 mm at pipe-forming installation 8-16" with pilger mills out of bi-metal thought high blank ingots produced by electroslag remelting process of low-ductile steel "04?14?5?2?-?" with boron content from 2.0 to 3.0% to manufacture hex blank pipes with turnkey size 252.6±1.8×5.0+1.5/-1.0×4300+80/-30 mm for tight storage and transportation of the spent nuclear fuel. The method includes casting by the electroslag remelting process of the ingots with size 480×1800±25 mm out of low-ductile steel "04?14?5?2?-?" with boron content from 2.0 to 3.0%, with bottom and shrinkable parts out of ductile carbon steels; their height is from 0.04 to 0.05 and from 0.13 to 0.14 respectively of total ingot height, creating during rolling of the process pipes the seed ends and pilger small heads, turning of the outside surface of the electroslag remelting ingots to remove cast defects producing blank ingots with size 465±5×1800±25 mm; in them through central hole is drilled with diameter 100±5.0 mm; they are heated to 1030-1050°C, pierced in a mill for transverse screw rolling into sleeves with size 450×out.295×3080-3140 mm with swaging as per diameter ? from 2.2 to 4.3% and drawing µfrom 1.69 to 1.77, sleeves are rolled in the pilger mill in process pipe stocks with size 284×11×26100-26600 mm with drawing µ= 9.61 and swaging as per diameter ? = 36.2%; from pipes using hot cutting saw the process wastes are cut off, providing pipe ends out of ductile carbon steels with length 600-700 mm, from stub and pilger head side the pipe stocks by the hot cut saw are cut to pipes having multiple length and residue, multiple length pipes and residue are straightened in the six roller machine using the rolling heating temperature, at that the first multiple length pipe and residue are fed to the straightener by ends out of ductile carbon steels, the first multiple length pipe is cut in the machine from side of the carbon steel with length 5300±50 mm and residue, the second multiple length pipe is cut to two pipes with equal length, are bored and turned to the cylindrical blank pipes with size 278.5±1.8×5.0+1.5/-1.0 mm for profiling in hex blank pipes of specified size, sleeves are rolled in the process pipe stocks with size 284×11 mm in gauge 290 mm in mandrel bars with diameter 264/265 mm heated to 500-550°C by rolling of setting carbon sleeves as p