METHOD TO PRODUCE HEXAHEDRAL STOCK PIPES WITH FLAT-TO-FLAT DIMENSION 175×2,5+0,3/-0,2×2680+20/-0 mm FROM STEEL OF GRADE '16Х12МВСФБР-Ш (ЭП823-Ш)' FOR FAST FEEDER REACTORS

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to metallurgical and pipe rolling industries. Electroslag melting bars with size off 485×1600±25 mm are cast and turned into cakes with size of 470×1600±25 mm. A through hole is drilled with a diameter of 100±5 mm. Cakes are heated to temperature of 1120-1140°C and pierced in a cross-rolling mill into blooms with size of 480×vn.315×2500 mm. Cakes are rolled into pig hot-deformed stock pipes with size of 337×28×8000 mm in a gauge 340 mm on burnishers 282/286 mm with drawing of µ_n=3.79, clamping by diameter Δ=29.8% and feed of blooms into a deformation site m=16-18 mm. Stock pipes are straightened using temperature of rolling heating and cut into two stock pipes with size of 337×28×4000 mm. Stock pipes are turned and ground. Rolling of stock pipes on cold pilgering mills 450 and 250 is carried out along the routes: 325×12×4000---273×8×6680---219×4×16100 mm. Pipes are cut and rolled on the cold pilgering mill 250 into stock pipes with size of 194×2.5×14100 mm. At one of ends of stock pipes they drill a hole for a pivot of a pulling chain. Stock pipes are profiled into hexahedral pipes with a flat-to-flat dimension of 175±0.4×2.5+0.3/-0.2×14100 mm.;EFFECT: reduced discharge coefficient of metal.