METHOD TO PRODUCE HOT-ROLLED COILS FROM TUBE STEELS Russian patent published in 2010 - IPC B21B1/26 

FIELD: process engineering.

SUBSTANCE: proposed method comprises slab heating and rolling at broad-strip continuous rough-and-finish stands. It includes also differential water cooling of strip by feeding water from above by sprayer unit sections in finishing set of mill stands and outgoing roller table with subsequent strip coiling. High-quality hot-rolled coils with high strength and plasticity and with no crosswise cracks are produced by setting rolling end temperature is set for 16.1 mm-to-17 mm-thick strip equal to 770-810°C, and for, 17.1 mm-to-18.7 mm-thick strip it is set to make 750-790°C. Note here that strip surface cooling intensity is adjusted in rough-rolling stand spaces depending upon deformation in first stands of finishing rolling by varying cooling rate variation in compliance with mathematical relationships.

EFFECT: high-quality hot-rolled coils from 16,1-to-18,7 mm-thick tube steels with high strength and plasticity and with no crosswise cracks are produced in high-efficiency hot rolling mill, steel carbon content making 0,12 to 0,14%.

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