METHOD OF PRODUCTION OF COLD-ROLLED PIPES WITH SIZE VN346(40 MM FROM STEEL OF GRADE 08-18=10T-+ FOR NUCLEAR POWER ENGINEERING FACILITIES

摘要

FIELD: technological processes.SUBSTANCE: invention relates to pipe rolling Cakes with size of 620×100×1750±50 mm are heated to temperature of 1260-1270°C and are pierced in a cross-rolling mill into bloom stocks with size of 620×vn.265×1985-2105 mm on a holder with diameter of 250 mm true to size along external diameter and drawing µ=1.17. Blooms are heated from cold or hot charging to temperature of 1260-1270°C and pierced - rolled true to size along the outer diameter into blooms with size of 620×vn.390×2630-2800 mm on the holder with diameter of 375 mm with drawing µ=1.33. Blooms are rolled on a TPU 8-16" with Pilger rolling mills into stock hot-rolled pipes with size 480×58×5500-5800 mm with clamping by diameter ?=21.8% and drawing µ=2.37. Pipes are turned and bored into pig mechanically treated pipes with size of 470×47×5500-5800 mm with removal of metal on the outer surface at ?5.0 mm, and along the inner surface at ?6.0 mm, and roll them into pig hot-rolled mechanically treated pipes with size of 470×47×5500-5800 mm on a cold-pilgering mill 450 into commercial cold-rolled pipes with size of vn.346×40×6700-7200 mm with drawing µ=1.29 and clamping along diameter ?=9.36%, roughness of internal and external surfaces Ra of not more than 2.5 mcm.EFFECT: invention provides for reduced metal consumption.1 tbl