Continuous variational convexity degree rolling mill back-up shaft

Abstract

The invention provides a continuously variable crown mill support roll to be matched with a roll curve of a continuously variable crown work roll. The roll shape is skew asymmetrical curve which essentially consists of a roll gap whole line contact curve section in the range of the strip width at the middle of the roll body and a contact line variable curve section at two ends of the roll; and the roll shape curves of an upper support roll and a lower support roll are the same but are arranged reversedly in an angle of 180 degrees The continuously variable crown mill support roll with the roll shape curve and the mill roll system with the continuously variable crown work roll can not only reduce uneven distribution and peak of the contact pressure between the roll, reduce or eliminate side spalling of the continuously variable crown mill support roll with normal crown, improve service cycle and service life of the support roll and reduce roll consumption of the support roll, but also overcomes harmful contact zone outside the rolled strip width and improves roll gap lateral rigidity of the mill and plate shape control efficiency of bending force, thereby improving plate shape quality of the rolling strip.

Description

technical field [0001] The invention relates to a back-up roll used for strip shape control in the production of strip hot and cold continuous rolling mills and medium and thick plate rolling mills. Background technique [0002] The continuously variable crown rolling mill is a new generation of rolling mill widely used in hot strip rolling, cold continuous rolling and plate rolling. Outstanding representatives include: four-high CVC rolling mill, SmatCrown rolling mill, CVC plus rolling mill, SmatCrown plus rolling mill and six Roll CVC Mill. The roll system of a continuously variable crown mill consists of a pair of backup rolls and a pair of continuously variable crown work rolls (or a pair of backup rolls, a pair of continuously variable crown intermediate rolls and a pair of work rolls of a six-high mill). [0003] At present, the back-up rolls of continuously variable crown rolling mills mainly adopt conventional crown back-up rolls, conventional flat roll back-up rol...

AI Technical Summary

Problems solved by technology

[0004] Judging from the current use situation, the conventional convex back-up rolls used in SmartCrown tandem cold rolling mills are severely and unevenly worn, and the amount of wear can reach 1.2mm along the length of the roll body (the maximum amount of wear on one side of the back-up rolls once reached 3-4mm. The chamfering area of ​​the entire roll has been worn away), and the regular crown support rolls in normal industrial applications have severe "edge gnawing" peeling during each service period, seriously affecting the shape quality of the strip steel plate, and the service period was forced to be shortened from 25 days to 15 days. Tian; The back-up rolls of conventional flat rolls with circular arc chamfers on the edge of CVC and CVC plus hot rolling mills are severely worn, and local high points are formed in the area near 120mm from the edge of the roll. After the back-up rolls wear between the high points, the roll shape is similar S-shaped, and spalling occurs from time to time, and even 3 of the 14 backing rolls in one service period have severe spalling, and the average amount of turning and wear reaches about 55mm, while the amount of normal grinding and wear is only about 2.2mm; CVCB mainly It is a support roll for the work roll to change the crown of the roll gap and change the shape of the roll gap with the relative axial movement of the design. Under the premise of good self-maintenance of the roll shape, the combined use of the two is beneficial to improve the entire roll shifting The pressure distribution between the rolls within the stroke range improves the service life of the rolls and makes the control technology for axially moving the work rolls to change the roll gap convexity more perfect. In actual industrial production, the roll shape of the rolls during a service period is always unavoidable due to wear and other reasons. Therefore, CVCB can improve the problem of uneven pressure distribution between rolls in the entire range of roll shifting stroke when the rolls are in service, but it is difficult to ensure a more uniform pressure distribution between rolls in the middle and later stages of service; DSR support rolls are the current principle The ideal shape control technology can not only correct the symmetrical secondary shape defects, but also correct the high-order shape defects and asymmetric defects that are usually difficult to deal with, but the structure is complex and the metal sleeve is seriously worn during the strip rolling process , the use and maintenance costs in the industrial rolling process are relatively high, so the research on the use of DSR backup rolls needs to be further in-depth, and it has not reached the stage of industrial application in strip rolling

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