Thermal treatment method of wide and thick plate supporting roll

Abstract

The invention discloses a thermal treatment method of a wide and thick plate supporting roll. The thermal treatment method is used for carrying out thermal treatment on the surface of a roll body with the length of 3500-4300mm of a supporting roll workpiece and comprises the following steps: step one. preheating; step two. carrying out differential temperature heating, to be specific, firstly carrying out air burning on a differential temperature furnace for more than or equal to 4 hours at the temperature of 800-850 DEG C, and then transferring the preheated workpiece to the differential temperature furnace; heating to 1000-1050 DEG C, carrying out heat preservation for 2-5 hours, then cooling to 900-950 DEG C, and carrying out heat preservation for 2-6 hours; step three. carrying out spray quenching; and step four. tempering. The thermal treatment method can be used for improving the wear resistance of the supporting roll and prolonging the service life of the supporting roll and ensuring that the surface of the roll body of the supporting roll has good hardness and abrasive resistance, and a core part of the roll body and a roll neck have good synthesized mechanical properties; the non-burning overall heating quenching process manner of a conventional large-sized wide and thick plate supporting roll car-bottom type furnace is changed, the tempering frequency is reduced, the production cycle is shortened, and the production cost is reduced.

Description

technical field [0001] The invention relates to a heat treatment method for forged steel, in particular to a heat treatment method for a support roll of a wide and thick plate. Background technique [0002] The wide and thick plate rolling mill is a four-high rolling mill with backup rolls. The rolling load is transmitted to the backup rolls through the work rolls and intermediate rolls and finally borne by the backup rolls. The role of the backup roll is to support the work roll to reduce the bending deformation of the work roll so as to improve the thickness accuracy and shape quality of the plate. [0003] Large forged steel wide and thick plate back-up rolls with a roll body length of 3500-4300mm are large-sized and difficult-to-manufacture varieties in roll products. Petroleum pipes, boilers, marine development and machinery manufacturing are indispensable and extremely important steel products for modernization. In recent years, with the rapid increase of four-high r...

AI Technical Summary

Problems solved by technology

The back-up roll is rapidly heated up through the ordinary trolley-type gas furnace and properly maintained before it is sprayed and quenched. Since the roll neck of the back-up roll is heated together in the furnace, measures to protect the roll neck must be added during spray quenching, and secondary tempering is required after the overall tempering. In order to ensure the mechanical performance requirements of the roll neck, the existing heat treatment method has high production cost and low production efficiency

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