PRODUCTION OF 245×10-15 mm SEAMLESS HOT-ROLLED PIPES FOR STEAM BOILERS, STEAM PIPELINES AND MANIFOLDS OF PLANTS WITH HIGH AND SUPERHIGH STEAM PARAMETERS FROM ESR INGOTS OF "10Х9МБФ-Ш"-GRADE STEEL Russian patent published in 2014 - IPC B21B19/04 

FIELD: process engineering.

SUBSTANCE: invention aims at decreasing the costs of 245x10-15 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. Pipes are made from ESR ingots-billets. Decreased metal input and quantity of equipment faults result from application of 430×100×1750±50 mm-ingots to be heated to 1180-1190°C, rolled at helical rolling machine to sleeves sized to 460xID.265×2060-2180 mm at 250 mm diameter mandrel with rolling-out µ=1.21 and diameter reduction of 6.9-7.1%. Said ingots-billets are heated to ductility temperature and rolled at Pilger mill on taper mandrels to rerolled hot-rolled pipes sized to 273×16×14200-15200 and 273×19×11600-12500 mm at feed m=16-18 mm, with rolling-out µ=8.60 and µ=7. 32 and diameter reduction δ=40.7% Pipes are cut to equal-size lengths Pipes are turned, bored and rolled at mill CPR 250 to commercial pipes sized to 245×10×12100-1300, 245×11×11000-11800 mm and 245×12×10100-10800 mm with rolling-out µ=1.75, µ=1.60 and µ=1.47. Pipes sized to 273×19×5800-6250 mm are rolled at CPR 250 mills to commercial pipes sized to 245×13×8500-9300, 245×14×8000-8600 and 245×15×7800-8400 mm with rolling-out µ=1.53, µ=1.43 and µ=1.40. Commercial pipes are cut to the order, heat treated, straightened and accepted with diameter allowance of ±1.0% wall allowance of +15/-5.0.

EFFECT: lower metal loses, decreased equipment faults.

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