PRODUCTION OF 325×46-60 mm SEAMLESS HOT-ROLLED PIPES FOR STEAM BOILERS, STEAM PIPELINES AND MANIFOLDS OF PLANTS WITH HIGH AND SUPERHIGH STEAM PARAMETERS OF "10Х9МФБ-Ш"-GRADE STEEL Russian patent published in 2015 - IPC B21B19/04 

FIELD: metallurgy.

SUBSTANCE: this process comprises making of ESR ingots and their turning to 490×2000±50 mm ingots-billets. Through central 100±5 mm diameter bore is drilled therein. Said ingots-billets are heated in continuous furnace to 1160-1170°C, pierced at helical rolling mill to 500xOD265×2440-2560 mm or 500xOD225×2180-2300 mm sleeves at 250 mm and 210 mm diameter mandrels with rolling-out µ = 1.25 and µ = 1.12 with increase in diameter δ = 2.04%. Said sleeves are rolled at PRU 8-16" with Pilger mills to commercial long 325×46×6700-7100 - 325×60×5400-5700 mm pipes with rolling-out of µ = 3.32 to µ = 2.98 and diameter reduction Δ = 34.0%. Sleeves are fed to deformation centre m = 22-26 mm, process wastes are cut off as seed ends and Pilger heads by hot cutting saw. Pipes are heat treated, etched and subjected to ultrasound control and acceptance with pipe diameter tolerance of +1.25/-1.0% and wall thickness tolerance of +20.0/-5.0%. Long pipes are produced to comply with requirements of Specs TU 14-3P-55-2001.

EFFECT: compliance with specifications.

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