METHOD FOR MAKING COILS OF HOT ROLLED STEEL STRIPS FOR TUBE PRODUCTION Russian patent published in 2006 - IPC B21B1/26 

FIELD: rolled stock production, possibly manufacture of hot rolled strips for making electrically welded tubes.

SUBSTANCE: method for making coiled steel, mainly with carbon content 0.17 -0.20% and thickness 5 -14 mm comprises steps of rolling steel in rough and finish continuous groups of stands of wide-strip rolling mill; differentiated cooling of strip with water from upwards and downwards by means of sections of sprinkling apparatus on outlet roller table; coiling steel. Temperature of rolled piece in last pass of rough group of stands is sustained no more than 1080°C. In last two passes of finish group of stands rolling is performed at total percentage reduction 25 - 39%. Temperature of rolling process termination in finish stand group is sustained in range 790 - 875°C, then rolled piece is cooled on outlet roller table. Relation of flow rates of water supplied for cooling strip from downwards and from upwards is 2 :1. Temperature of strip before coiling it is sustained in range 500 - 570°C. Winding of lead end of strip onto drum of coiler is realized at guiding speed 135 -360 m/min at further acceleration no more than 0.04 m/sq.s.

EFFECT: elimination of tube distortion at their further heat treatment, desired degree of mechanical properties of steel strips, monotonous scale content on strip surface.

3 cl, 1 ex, 1 tbl