PRODUCTION OF 273×9-15 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 2014 - IPC B21B19/04 

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Proposed method comprises casting the ingots by electric slag remelting. Hollow ingots are bored and turned to ingots-blanks sized to 540×ID360×3200±50, their heating in continuous furnace to 1170-1180°C. They are rolled at PRU 8-16" with Pilger mill to rerolled pipes sized to 377×20×15100-15650 and 377×22×13500-14000 mm rolling-out µ=5.59 and µ=5.08, diameter reduction of 29.6% and sleeves-billets are fed to strain source m=17-20 mm. Hot cutting saw is used to remove process wastes in the form of Pilger heads and seed ends Pipes are cut to two equal-length pipes, straightened and heat treated, and repaired is required. Then, they are subjected to ultrasound control and acceptance with diameter and wall depth allowances of +1.25/-1.0% and ±12.5%, respectively.

EFFECT: higher mechanical properties, precision and surface quality.

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