PRODUCTION OF 377×14-19 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. This process comprises heating the ESR ingots-billets sized to 565×100×1750±50 mm to 1200-1210°C and piercing them at helical rolling mill at 275 mm diameter mandrel with rolling out µ=1.20 and diameter increase of 2.6-2.8% to sleeve billets sized to 580×ID290×2040-2160 mm. Sleeve billets are cooled, reheated from cold or hot charging to 1210-1220°C. Then, these are pierce at helical rolling mill at 400 mm diameter mandrel with rolling-out µ=1.32 and diameter increase of 3.4-3.6% to sleeves sized to 600×ID415×26900-2850 mm. Sleeves are rolled to rerolled pipes sized to 426×21×11800-12700 mm and 426×23×10150-11000 mm. Rerolled pipes sized to 426×21×5900-6350 mm are rolled with rolling-out µ=1.67, µ=1.57 and µ=1.47 to commercial pipes sized to 377×14×9550-10300, 377×15×9200-9970 and 377×16×8700-9050 mm. Rerolled pipes sized to 426×23×5075-6350 mm are rolled with rolling-out µ=1.52, µ=1.43 and µ=1.36 to commercial pipes sized to 377×17×7700-8350, 377×18×7250-7850 and 377×19×6900-7500 mm.

EFFECT: higher mechanical properties and precision of pipe sizes.

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