PRODUCTION OF 465×15-60 mm SEAMLESS HOT-ROLLED PIPES FOR STEAM BOILERS, STEAM PIPELINES AND MANIFOLDS OF PLANTS WITH HIGH AND SUPERHIGH STEAM PARAMETERS FROM ESR INGOTS OF "10Х9МФБ-Ш"-GRADE STEEL Russian patent published in 2015 - IPC B21B19/04 

FIELD: process engineering.

SUBSTANCE: invention relates to pipe rolling. ESR ingots are turned to drill central 100±5 mm bore to get ingots-billets sized to 565×100×1750±50 mm. Ingots-billets are heated to 1200-1210°C and pierced to 580×290×2040-2160 mm with diameter increase of 2.5-2.8%. Reheating is performed from cold charging to 1190-1200°C, ingots-billets are pierced-rolled with diameter increase of 3.4-3.5% and rolled to commercial pipes at Pilger mill. Rolling at Pilger mill is performed with feed of $$m_j=m_{21}+\frac{m_{21}}{{\mu }_i}$$ , where m₂₁-15-16 is geed at rolling pipes with wall depth of 21 mm; µ_i is rolling-out at 426mm-dia pipes with i^th wall depth. Process wastes are cut by hot cutting saw, pipes are straightened at six-roll straightener, heat treated, etched and subjected to ultrasound control and acceptance.

EFFECT: higher mechanical properties and precision of pipe sizes.

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