METHOD FOR CONTROL OF SHEET ITEM HARDNESS Russian patent published in 2009 - IPC C21D1/52 C21D9/56 F27B9/28 

FIELD: technological processes.

SUBSTANCE: invention is related to the field of thermal treatment. For even heating of sheet in its section, sheet material (2) is heated in industrial furnace to obtain previously defined profile of temperature by length (3) and width (4) of material (2), at the same time sheet material (2) is displaced in furnace (1) relative to at least one burner unit (6), which is installed lower than this material (2) and/or at least one burner unit (6), which is installed higher than this material (2), at the same time each of units (6) comprises a row of burners (7) with direct action of flame torch, which are installed in a row abreast each other, besides burners (7) with direct action of flame torch are inverted in direction of sheet material (2), and separate burners (7) in each unit (6) are controlled to provide a previously defined thermal power, moreover, at least one of separate burners (7) with direct action of flame torch is inclined relative to longitudinal axis (13) of unit (6), on which it is installed, as a result of which position of longitudinal axis of separate burner (7) is controlled to specify angle (A) relative to surface of sheet material (2), which is different from 90°, at the same time gaseous or liquid fuel and oxidant containing more than 80 weight percents of oxygen are supplied into each burner (7). According device is also used, which makes it possible to realise the specified method.

EFFECT: method is suggested for control of sheet item hardness.

12 cl, 4 dwg