PRODUCTION OF 273×9-60 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 B21B19/00 

FIELD: process engineering.

SUBSTANCE: invention relates to pipe rolling. ESR 470×100×1750±50 mm ingots are heated to 1200-1210°C and rolled at screw rolling mills to 500×ID365×2980-3150 mm sleeves at 350 mm diameter mandrel with rolling-out µ=1.75 lift in diameters of 6.3-6.5%. Sleeves are rolled to 377×22×8000-8500 mm pipes with rolling-out µ=3.74 diameter reduction of 24.6%. Pipes are heat treated and rolled at CPR 450 mill to 325×15×13200-14000, 325×16×12400-13200, 325×17×11700-12400 and 325×18×1100-11800 mm pipes with rolling-out µ=1.68, µ=1.58, µ=1.49 and µ=1.41. Said pipes cut to pipe lengths 325×15×6600-7000, 325×16×6200-6600 mm, 325×17×5850-6200 mm, 325×18×5500-5900 mm are rolled at CPR 450 mill to commercial pipes sized to 273×9×12600-13300 mm, 273×10×11300-12000 mm, 273×11×10300-1100, 273×12×9400-10100 and 273×13×8600-9300 mm with rolling-out µ=1.96, µ=1.88, µ=1.82, µ=1.76, and µ=1.64. Then, they are subjected to ultrasound control and acceptance with diameter and wall depth allowances of +1.0% and +15/-5%, respectively.

EFFECT: higher surface quality and precision.

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