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

FIELD: metallurgy.

SUBSTANCE: invention relates to rolling industry and can be used during manufacturing on hot-rolling mills with maximal rolling stress in each mill of finishing train not more than 3500 tones of wide got-rolled strips predominately made of low-alloyed steel of strength grade K52 for following manufacturing of welded pipes. Steel contains predominately 0.11-0.15% of carbon. Method includes slab heating, hot rolling in mills of rough group and following rolling of strip in finishing continuous train of wide-strip hot mill with its surface cooling by water in inter-mill gaps and on collecting roller table with following strip winding into roll. At content in steel of manganese (Mn) 1.45-1.55%, niobium (Nb) and vanadium (V) not more than 0.01% of each of elements at strip cooling on collecting roller table water on its surface is delivered after 9-11 seconds after finish of hot rolling. Strip winding temperature is installed in the range from 540-580°C.

EFFECT: invention provides mechanical properties, corresponding strength grade K52, in conditions of continuous wide-strip hot mill, allowing low crimping ability of finishing train.

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