RU2745920C1 - Method for producing rolled rectangular section from substandard rolled round section - Google Patents

Abstract

FIELD: rolling.

SUBSTANCE: invention relates to rolling and namely to the production of a rolled rectangular section from a substandard rolled round section. The method includes heating a round billet and sequential rolling in calibers of mills. Rolling is carried out in a group of universal stands in universal calibers with the addition of two-roll system calibers as auxiliary ones until a rectangular profile of the required dimensions is obtained. The ratio of the cross-sectional area of ​​the round billet to the cross-sectional area of ​​the resulting rectangular profile exceeds 1.3.

EFFECT: invention provides a wide range of rolled products. The invention eliminates the need of remelting products and associated costs.

1 cl, 3 dwg, 3 ex

Description

The invention relates to rolling production, in particular to the production of section profiles.

Known system of calibers for rolling round profiles [1] (copyright certificate SU No. 1475742, IPC B21B 1/16, published 04/30/1989, bulletin No. 16), where the method of rolling round profiles, consisting of a system of calibers "rectangle - circle" from round billet, while rolling is carried out in a four-high rib groove of a rectangular profile with convex working surfaces of horizontal rolls, and then in a two-high round groove. The wire or rod is set in a groove formed by rolls with convex working surfaces, with a ratio of the height of the groove to its width in the range of 1.1-1.8. Then the strip in the form of an unfulfilled tetrahedron is rolled in a round 2-roll groove.

When rolling a round billet in a rectangular four-roll caliber, the deformation zone is divided into two-roll and four-roll zones due to the inequality of the height and width of the caliber. To reduce the length of the deformation zone of the two-roll zone and increase the four-roll zone, in the proposed system rolls with a smaller diameter are made with a convex surface.

Such a geometry of the rolls is also necessary from the point of view of increasing the stability when rolling a rectangular strip in a round two-roll caliber. In addition, a prerequisite for rolling is the relative position of the four-roll and two-roll calibers, namely, the calibers should be located so that the axes of the four-roll caliber rolls having a convex surface are parallel to the axes of the round caliber rolls.

The disadvantage of this system is that the resulting profile can only be round.

There is a known method of rolling profiles of circular cross-section [2] (patent RU No. 2170150 IPC B21B 1/00, published 10.07.2001, bulletin No. 19), including sequential deformation of the rolled stock in rough, pre-finishing and finishing round gauges, to ensure the accuracy of the shape of the finished round profile over the entire section and high-quality study of the metal structure, rolling is carried out in the "rectangle - square - circle" gauge system, while at the initial stage the rectangular billet is rolled in open box and universal square 4-roll calibers until a square roll is obtained, and the final pass carried out in a round universal 4-roll caliber, in addition, the ratio of the side of the square workpiece to the diameter of the round caliber should be as a / D = 0.90 - 0.92.

The disadvantage of this method is that the resulting profile can only be round, obtained from a rectangular blank.

The closest (prototype) in technical essence to the claimed method, in terms of the number of similar features, is a method for the production of rolled products on a casting and rolling unit [3] (patent RU No. 2143956 IPC B21B1 / 46, published 01/10/2000, bull. No. 1), including casting metal from casting ladles on a continuous billet casting machine, cutting and heating the resulting billets and rolling them in a reversing stand, while metal casting is carried out into square or round billets of a size range with a ratio of the maximum and minimum dimensions of the sides and diameters equal to 1.4 , while the sectional area of each billet is 1.3 ... 5.6 of the sectional area of the finished rolled product from it, and rolling in the reversing stand is carried out in 2 ... 6 passes with a total stretch of 1.3 ... 3.6.

The disadvantage of this method is that in the process of rolling the wheel, there is a possibility of defects associated with both the deviation of geometry, chemical composition, inconsistency with mechanical characteristics, and due to overproduction, this rolled product is sorted out and then transferred to remelting.

The technical result to be achieved by the alleged invention is: the ability to roll substandard products in the form of round bars into a square billet of appropriate size and quality.

The technical result is achieved due to the fact that in the method of producing rectangular rolled products from substandard round rolled products, including heating a round billet, sequential deformation (rolling) in the calibers of the mills, the following differences are provided:

- rolling is carried out in a universal stand, or in a group of universal stands, until a rectangular profile of the required dimensions is obtained;

- in this case, the ratio of the cross-sectional area of the round billet to the cross-sectional area of the resulting rectangular profile should be more than 1.3.

In addition, sequential deformation (rolling) is carried out in universal calibers with the addition of two-roll system calibers as auxiliary ones.

In the claimed invention, it is proposed to use mills equipped with a group of universal stands for rolling these products into a square billet or a billet of rectangular cross-section with the required geometry and mechanical characteristics and its further use both in mechanical engineering and as a raw material for small and medium-sized mills.

The essence of the invention is illustrated by drawings, where:

- FIG. 1 shows a diagram of rolling a square 93 from a circle with a diameter of ∅ 120 mm;

- FIG. 2 shows a diagram of rolling a square 100 from a circle with a diameter of ∅150 mm;

- FIG. 3 shows a diagram of rolling a square 130 from a circle with a diameter of ∅170-180 mm.

The essence of the proposed method is as follows.

The proposed invention is a technology for rolling a circle in a mill equipped with a group of universal stands.

Depending on the initial section of the circle to be rolled and the final resulting profile of the rectangular section, the rolling pattern may include the following combinations:

GUK

VK-GUK

GUK-VK-GUK

VK-GUK-VK-GUK

GUK-VK-VK-GUK

GUK-GUK-VK-GUK

VK-GUG-GUK-VK-GUK,

VK (Auxiliary stand), GUK (Main universal stand)

Examples of these combinations are shown in the diagrams (FIG. 1, FIG. 2, FIG. 3).

In contrast to the analogue patent No. 2143956 in the proposed invention, the production of a blank of rectangular (square) section occurs:

- in the group of stands, including universal grooves from substandard rolled round section.

In contrast, copyright certificate No. 1475742 in the proposed invention:

- rolling is performed from substandard round billets

- the section of the finished profile is not round, but square.

- rolling is carried out in a four-roll gauge of a rectangular profile, not with convex working surfaces, but with parallel

- the number of passes is much less due to the absence of intermediate gauges

Unlike analogue patent No. 2170150, in the proposed invention:

- rolling is performed from a substandard round billet, not from a rectangular one

- the section of the finished profile is not round, but square.

- the number of passes is much less due to the absence of intermediate gauges

- no pre-rolling in open box gauges is required.

The peculiarity of the application of these schemes lies in the mandatory presence of universal stands, which will ensure uniform reductions in both the vertical and horizontal directions during the rolling process, the absence of twisting of the workpiece from the occurrence of multipolarity of forces, the absence of the need to determine the location of the "mark" on the formed round workpiece, and the elimination of after rolling it in a universal cage.

Obtaining the final profile is characterized by the rolling concept, as well as by the specified distances between the rolls and the size of the guaranteed clearances.

Rolling a round billet by the above method makes it possible to obtain the final section with the ratio of the areas of the circle to the area of the rectangular section ΔS = 1.3 and higher.

Example # 1:

Produce square rolled products with a side of 93 mm. - from a workpiece with a diameter of 120 mm. A round billet with a cross-sectional area of 11309 mm. rolled in a universal gauge, and get a square with a rolling area of 8525 mm. In this case, ΔS = 1.33. Rolling is carried out according to the scheme - a round billet after heating is set into a universal gauge. Finished rolled products are delivered to hot-cut saws.

Example # 2:

Produce square rolled products with a side of 100 mm. - from a workpiece with a diameter of 150 mm. A round billet with a cross-sectional area of 17671 mm. rolled in universal gauges with alternating box, and get a square with a rolling area of 9806 mm. In this case, ΔS = 1.80. Rolling is carried out according to the scheme: after heating, a round billet is set into a universal gauge - box - universal gauge. Finished rolled products are delivered to hot saws.

Example No. 3:

Produce square rolled products with a side of 130 mm. - from a workpiece with a diameter of 170-180 mm. A round billet with a cross-sectional area of 22698-25447 mm. rolled in universal gauges with alternating box, and get a square with a cross-sectional area of 16622 mm. In this case, ΔS = 1.37-1.53. Rolling is carried out according to the scheme: after heating, a round billet is set into a universal gauge - box - universal gauge. Finished rolled products are delivered to hot saws.

With a decrease in the section of one of the sides of the rectangle to the other section on the resulting profile, this ratio will increase.

The limiting factor in the produced section will also be the size of the defect of the round billet, which should not go beyond this ratio.

It has been confirmed that the use of the method for the production of rectangular rolled products from substandard round rolled products allows:

- to roll substandard sorted round billets with deviations into suitable products in the form of a rectangular section and its further use both in mechanical engineering and as raw materials for small and medium-sized mills, with no return to remelting and associated costs.

- to eliminate the need to determine the location of the "mark" on the formed round billet, and to eliminate it after rolling in a universal stand, which does not require intermediate operations for upsetting the billet and the cost of these operations.

- A wide range of produced assortment of rectangular cross-section: squares for mechanical engineering, rolling, rectangular billets for various purposes, and the presence of a mass market for the possibility of its further implementation.

Information sources

[1] Copyright certificate SU No. 1475742, IPC B21B 1/16, published 04/30/1989, bull. N 16);

[2] Patent RU No. 2170150, IPC B21B 1/00, published on July 10, 2001, bulletin No. 19;

[3] Patent RU No. 2143956, IPC B21B 1/46, published 10.01.2000, bull. # 1.

Claims (1)

A method for the production of rectangular rolled products from substandard circular rolled products, including heating a round billet and sequential rolling in mill calibers, characterized in that rolling is carried out in a group of universal stands in universal calibers with the addition of two-roll system calibers as auxiliary ones until the required rectangular profile is obtained. dimensions, while the ratio of the cross-sectional area of the round billet to the cross-sectional area of the resulting rectangular profile exceeds 1.3.

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