JPH0289502A - Method and rolling mill line for rolling shape steel - Google Patents

Abstract

PURPOSE:To obtain shape steels of various sizes in the same rolling operation by performing finish rolling combining flange raising with roll widths properly changed by segmented rolls for web thickness drafting in which a roll width is changeable in accordance with a variable amount of a rolled stock web width. CONSTITUTION:A shape stock 1 is subjected to one or more rolling passes by U1 and U2 mills under a condition in which the flange parts F are restricted and then rollings whose final pass being performed by the U1 mill are performed to obtain a necessary width spreading amount Z ( X h). Next, both web end regions of the stock 1 are drafted to have an equal thickness to that of the web central region and are spread and are subjected to finish rolling combining flange raising by rolls 4 of a UF mill. Hence, shape steels of various sizes are manufactured by increasing variable amounts of a web width of stocks without frequent change of rolls.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is capable of manufacturing H-shaped, groove-shaped, or similar steel sections of various sizes within the same roll machine without requiring frequent changes of rolls. The present invention relates to a rolling method that is advantageous in the field of technology and a rolling mill train suitable for carrying out the method.

(Prior art) Examples of prior art related to the manufacture of shaped steel include JP-A No. 6
References may be made to JP-A No. 2-161403, JP-A-59-133902, and the like.

(Problems to be Solved by the Invention) The technology disclosed in the above publication attempts to freely adjust the web height of IJ section steel, etc. within the same roll chance by subjecting the web portion of the material for section steel to partial rolling. However, the amount of adjustment is about 20 mm at most, and the degree of freedom is extremely small.

It is an object of the present invention to propose a rolling method and a rolling mill train that can increase the amount of variation in web width during rolling of a section and produce sections of various sizes within the same roll machine.

(Means for Solving the Problems) In manufacturing a section steel having a web and a flange, the present invention involves rolling that applies local reduction to the central region of the web portion of the material for the section steel, and rolling reduction to each of the both end regions of the web section. The material is rolled at least once under the restraint of the flange portion of the material, and then the roll width is changed using a split roll for web thickness reduction whose roll width is variable according to the amount of change in the required web width of the material. A method for rolling section steel characterized by performing finish rolling that also serves as flanging while making appropriate adjustments,
Further, the present invention provides a universal rolling mill equipped with a pair of rolling rolls that have a convex portion over the entire circumference of the central region in the width direction of the rolls and roll down the web portion of a section having a flange and a web portion in the thickness direction thereof. On the exit side, there is a universal rolling mill equipped with a pair of web thickness reduction rolls with a flat roll surface and a universal rolling mill equipped with a web thickness reduction roll pair with a split structure that allows the roll width to be freely changed. This is a row of rolling mills.

The present invention will be explained below by taking as an example the rolling of an H-section steel provided with a flange and a web.

FIG. 1 schematically shows a rolling mill row according to the present invention. In the figure, U indicates a convex portion extending over the entire circumference of the central region in the width direction of the roll. ) is a universal rolling mill equipped with a pair of rolls 2 for rolling down the web part W in the thickness direction, E on the exit side is an edge rolling machine, and U2 is a pair of rolls 3 for rolling down the web thickness with a flat roll surface. The UF is a universal rolling mill equipped with a web thickness reduction roll 4 that moves in the width direction of the web portion of the profile 1 and has a divided structure in which the roll width is variable.

(Function) In this invention, after passing through a breakdown mill,
is first rolled at least once by U and U2, and then U
Perform finish rolling by F.

(1), when expanding the web width of profile 1 Fig. 2 (a)
As shown in Figure 1, first, the flange part F of the profile L is rolled at least once using the U1 mill and the U2 mill with the flange part F restrained, and then a final pass is performed to obtain the required widening amount Z (Δ2×Δh). Next, both end regions of the web of the profile 1 are rolled down to the thickness of the central region of the web using UF rolls 4, and finish rolling is performed while widening the web and also serves as flanging.

(2) When reducing the web width of profile 1 as shown in Fig. 2(b)
As shown in the figure, the roll width of the roll 4 of the UF mill is reduced in advance, and the profile 1 that has been rolled at least once by the U1 and U2 mills is passed through the U mill, and the web part W of the profile 1 is rolled. Finish rolling, which also serves as flange raising, is performed while rolling down and reducing in the width direction.

(3) When performing normal rolling without enlarging or reducing the web width of the section 1, the section 1 that has been rolled by the U+ and U2 mills is rolled into the web of the section 1, as shown in Figure 2 (c). Finish rolling, which also serves as flanging of the profile 1, is performed by passing it through a U mill equipped with rolls 4 whose width is approximately equal to the roll width.

As described above, in this invention, the web width of the profile l can be freely changed according to the required variable amount.

In addition, in the case of expanding the web width of the profile L as in (1) above, U2 is
If the web width is widened without using vertical rolls during final rolling by a mill, it is advantageous to increase the amount of width widening at the final rolling stage (see the broken circle in FIG. 2(a)).

(Example) Size H-450X200X7X12~450X2
An attempt was made to manufacture an H-section steel with dimensions of 00 x 14 x 28. As a result, it was confirmed that it was possible to manufacture H-beam steel with a web width of up to +16 mm when expanding the web width, and up to -45 mm when reducing the web width without causing product defects.

(Effect of the invention) According to this invention, frequent reshuffling of rolls is not required (
By increasing the variable width of the web width of the section, it is possible to manufacture sections of various sizes. Further, according to the present invention, when manufacturing a steel section with a constant web height, even if roll wear occurs, the steel section with the same height can always be stably produced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a rolling mill row according to the present invention, and FIG. 2 (a
)(b) and (c) are explanatory diagrams of the rolling procedure according to the present invention. Figure 2 Figure 1 - Figure 2 (b) (C)

Claims (1)

[Claims] 1. In manufacturing a section steel having a web and a flange, rolling is performed to apply a local reduction to the central region of the web portion of the material for the section steel, and rolling to apply reduction to both end regions of the web portion, respectively. The material is rotated at least once under the constraint of the flange portion of the material, and then the roll width is adjusted as appropriate using a divided roll for reducing the web thickness, the roll width of which is variable according to the amount of change in the required web width of the material. A method for rolling section steel, characterized by performing finish rolling that also serves as flanging. 2. Providing a universal rolling mill equipped with a pair of rolling rolls that have a convex portion over the entire circumference of the central region in the width direction of the rolls and roll down the web portion of a section having a flange and a web portion in the thickness direction, On the exit side, a universal rolling mill equipped with a pair of web thickness reduction rolls with a flat roll surface and a universal rolling mill equipped with a web thickness reduction roll pair with a split structure that allows the roll width to be freely changed are installed. A row of rolling mills.