METHOD OF PRODUCTION OF HOT-ROLLED PIPE STEEL ROLLS Russian patent published in 2009 - IPC B21B1/26 

FIELD: metallurgy.

SUBSTANCE: method includes slab heating for hot rolling, its rolling in roughing and finishing continuous mill group of broad-strip mill, differentiated cooling of strip by water on collecting roller table with following reeling into roll. Receiving of required viscous characteristic, specifically, cold resistance and strength due to formation of ferrite grain no larger than 9 grade and of streakiness no more than 2-grade is provided ensured by that hot rolling in finishing mill group is implemented with total percent reduction no less than 82%. Temperature of hot rolling in finishing mill group is determined in range of 845÷875°C. After hot rolling finishing on collecting roller table at first three seconds strip cooling is implemented at a rate 18÷25°C/s, then cooling rate is determined 7÷9°C/s. Strip is reeled into roll at the temperature 520÷560°C.

EFFECT: optimal microstructure in hot-rolled strip made of pipe steel grades with microalloying by niobium.

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