RU2377086C1 - Operation method of working rolls of cold rolling mills - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention is provided for life extension of working rollers of cold rolling mills for rolling of strip steel and reduction of production expenditures. Method includes charging of rollers into mill stands and unloading from stands at particular degree of wear of body of rolls. Reduction of removal of rollers metal at refacing is provided ensured by that rollers are originally charged into stands where it is used trimming with convex or concave generatrix of its bodies, and then - into stands with opposite trimming, correspondingly, with convex or concave generatrix of its bodies, herewith value of arrow of convex generatrix is in the range +0.35…+0.40 mm, and arrow of concave generatrix is - 0.25 mm.

EFFECT: reduction of rollers metal removal at refacing.

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Description

The invention relates to equipment for metal forming and can be used in the operation of rolls of continuous mills of cold strip steel.

In order to reduce the wear of the work rolls of these mills, as well as to obtain the required geometry of the finished product, the roll barrels are made either convex or concave, i.e. with a given diameter difference in the middle of the length of the barrels and along the edges. Features of the operation of sheet rolls and their profiling are described, for example, in the book of MV Kovinev and VV Miller “Production of sheet metal”, M., “Metallurgy”, 1976, p.70-87.

There is a method of operating rolls of sheet rolling mills, in which the support rolls of a hot rolling mill after reducing the diameter of their barrels by 2.5 ... 2.85 are installed in the first stands of a cold rolling mill with the same length of roll barrels, after changing the configuration of the ends of their axes (see Pat. of the Russian Federation No. 2212291, class B21B 28/02, published in BI No. 26, 2003). However, this method is unsuitable for the work rolls of a cold rolling mill.

The closest analogue to the claimed object is the technology of operation of rolls of sheet rolling mills, described in the book by V. F. Zotov and V. I. Elin “Cold rolling of metal”, M., “Metallurgy”, 1988, p.99-101.

This technology includes filling the rolls in the mill stand and dumping from the stands and is characterized by the fact that the last operation is carried out when the surfaces of the roll barrels that are subjected to grinding are worn. A disadvantage of the known technology is the non-use of spent rolls directly in other stands of the mill, which reduces the life of the rolls.

The technical task of the present invention is to extend the life of the work rolls of continuous mills for cold rolling of strip steel and reduce production costs.

To solve this problem, in a method of operating rolls, including filling the rolls in the mill stand and rolling out the stands with a certain degree of wear on the roll barrels, the work rolls are initially dumped in a stand where profiling with a convex or concave barrel forming them is used, and then in a stand with opposite profiling, respectively, with a concave or convex generatrix of the barrels, while the size of the arrow of the convex generatrix is within + 0.35 ... + 0.40 mm, and the arrow of concavity of the generatrix is 0.25 mm.

The given roll profiling parameters are obtained empirically and are empirical.

The essence of the proposed technical solution is to reuse the working worn rolls in other stands of the mill, and without any additional processing, which reduces production costs. In practice, it is possible to “transfer” the rolls from one mill to another, for example from a temper mill 2500 to a cold rolling mill 2500 containing four stands.

Experimental verification of the proposed method was carried out at OJSC "Magnitogorsk Iron and Steel Works". For this purpose, two options have been tested for the use of spent work rolls: the proposed one and with their installation in stands containing rolls with similar profiling. The results of the experiments were evaluated by the duration of the working campaign of the rolls and the value of production costs.

The best results (the maximum duration of the rolls at the lowest cost) were obtained using the proposed method. When filling the spent rolls in a stand of the same mill with the same profiling, the duration of their work decreased by an average of 50% with a corresponding increase in production costs.

The use of spent rolls of the training mill in the stands of a continuous four-stand mill required additional preparation (regrinding) of the surfaces of their barrels in both variants. For the proposed version of the operation of the rolls, the removal of metal during regrinding was almost two times less, which not only reduced production costs, but also extended the working campaign of the rolls.

The known technology for the operation of rolls, taken as the closest analogue (see above), was not tested in experiments, since it does not provide for the reuse of used rolls. Thus, an experimental verification confirmed the acceptability of the technical solution found to achieve the goal and its advantage over a known object.

Feasibility studies carried out in the Central Control Laboratory of OJSC MMK showed that the implementation of the present invention on a continuous cold rolling mill 2500 will extend the operation of the work rolls of this and the temper mill 2500 no less than 1.5 times, and production costs four-stand mill to reduce by an average of 20%.

Concrete example

Work rolls heaped on the following route:

Driving route Training Mill 2500 1st crate of 4 cells camp 2500 4 crate 4 cells camp 2500 2nd cage of 4 cells camp 2500 3rd crate of 4 cells camp 2500 Steam profiling, mm +0.70 + 0.80 -0.50 -0.50 -0.50

Claims (1)

A method of operating the working rolls of a cold rolling mill, including filling the rolls in the mill stand and rolling out the stands for a given degree of wear of the roll barrels, characterized in that the rolls are initially dumped in stands that use profiling with a convex or concave barrel forming them, and then in a stand with opposite, respectively concave or convex profiling forming their barrels, while the size of the arrow of the convex forming is within + 0.35 ... +0.40 mm, and the arrow of the concave forming is 0.25 mm.