MANUFACTURING METHOD OF SEMI-FINISHED HOT-ROLLED MECHANICALLY PROCESSED PIPES WITH SIZE OF 325×12 mm WITH INCREASED ACCURACY AS TO DIAMETER AND WALL FROM STEEL GRADES "12Х12М1БФРУ-Ш", "16Х12МВСФБР-Ш" FOR REROLLING ON "ХПТ" 450 AND "ХПТ" 250 MILLS INTO SEMI-FINISHED PIPE WORKPIECES WITH SIZE OF 202±1,2×3,5+0,3/-0,2 mm AND FURTHER SHAPING INTO HEXAGONAL PIPE WORKPIECES WITH FLAT-TO-FLAT SIZE OF 181,8±0,4×3,5+0,3/-0,2×3750+20/-0 mm AND 175±0,4×2,5+0,3/-0,2×2680+20/-0 mm FOR FAST NEUTRON REACTORS OF NEW GENERATION Russian patent published in 2015 - IPC B21B21/00 B21B19/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to a manufacturing method of semi-finished hot-rolled mechanically processed pipes with size of 325×12 mm with increased accuracy as to diameter and a wall from steel grades “12Х12М1БФРУ-Ш” and “16Х12МВСФБР-Ш” for their rerolling on ХПТ450 and ХПТ 250 mills into semi-finished pipes with sizes of 202±1.2×3.5+0.3/-0.2 mm and 194±1.2×2.5+0.3/-0.2 mm and further shaping into hexagonal pipe workpieces with flat-to-flat sizes of 181.8±0.4×3.5+0.3/-0.2×3750+20/-0 mm and 175±0.4×2.5+0.3/-0.2×2680+20/-0 mm for fast neutron reactors of a new generation. Hollow electroslag remelting ingots are cast from steel grade “12Х12М1БФРУ-Ш” with the size of 490×in290×2850±25 mm, and from steel grade “16Х12МВСФБР-Ш” with the size of 490×in290×3000±25 mm, which are turned and bored into hollow cakes with the size of 480×in300×2850±25 and 480×in300×3000±25 mm, heated up to the temperature of 1130-1150°C, rolled on pilger mills into semi-finished hot-deformed pipe workpieces with the size of 338×25×11200±100 and 338×25×11850±100 mm, straightened in a six-roll straightening machine, cut into two pipe workpieces with the size of 338×25×5600±50 and 338×25×5925±50 mm, bored and turned into pipe workpieces with the size of 325×12×5600±50 and 325×12×5925±50 mm with metal removal in the quantity of 6.5 mm along inner and outer surfaces.

EFFECT: reduction of a metal consumption coefficient.

5 cl, 1 tbl