JPH04288902A - Method for rolling h-beam - Google Patents

Abstract

PURPOSE:To provide the above method for rolling H-beam the web height of which can be adjusted arbitrarily, the workability is good, while surely keeping the high quality and the high yield, without reducing the production level and the rolling efficiency, without increasing the number of roll holding. CONSTITUTION:At first, the process that the exces metal is formed at the root part of the flange and web and the both ends of web with the universal roughing mill 11h, 11v. Next, with the rolling mill 12 attaching a set of rolls that the roll width can be adjusted, by rolling with setting the proper roll width larger than the inner width of web of the above process, the inner width of web is expanded, and also the process that the excess metal is rolled down until the thickness as same as the central part of the above process and almost of the rolling reduction of excess metal is transformed to the expansion of the inner width of web is executed. These two processes are repeated and the prescribed web height can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling method for freely adjusting the web height of H-section steel during rolling.

0002

[Prior Art] At present, H-beam steel manufactured by hot rolling has a wide range of dimensions depending on its use, but in recent years, there have been efforts to reduce the weight of structures using them, and to economically design them. From this point of view, the variety of these dimensions tends to further increase. If such a tendency is to be dealt with using known conventional techniques, the following problems will arise.

Generally, the rolling mill arrangement for manufacturing H-section steel is as shown in FIG. 5 of the attached drawings, which includes a breakdown rolling mill BD, a first edging rolling mill RE1, a first roughing universal rolling mill RU1, It is rolled by a second roughing universal rolling mill RU2, a second edging rolling mill RE2, and a finishing universal rolling mill FU. The dimensions of H-beam steel obtained by this conventional universal rolling method are shown in Figure 6.
As shown in , when the web height H, web inner width LH, and flange thickness t2 are, the relationship is H=LH+2t2, and the web inner width LH is the horizontal roll of the finishing universal rolling mill, if the amount of heat shrinkage during cooling is ignored. Width (LH in Figure 5)
F), the web height H is determined by the horizontal roll width and flange thickness of the finishing universal rolling mill.

For this reason, for example, H-section steel whose web height is constant regardless of the amount of change in flange thickness, or conversely, H-section steel whose flange thickness is constant and whose web height can be adjusted to any size, are manufactured. In this case, it is necessary to adjust the width of the horizontal rolls of the universal rolling mill to match the size of the H-section steel to be rolled. Therefore, the number of sizes to be rolled increases regardless of the flange thickness t2 and inner web width LH. It becomes necessary to replace the rolls with matching rolls, resulting in a significant reduction in operating efficiency. Also, during rolling, the rolling rolls are worn due to contact with the rolled material, and the width of the horizontal rolls, such as LHF in Fig. 5, decreases, so the web height H or flange thickness t2 of the rolled product decreases.
Variations occur. Therefore, it is impossible to use the horizontal roll repeatedly for rolling of a certain rolling size for a long period of time. Due to these factors, it has become almost impossible to economically manufacture products that satisfy customer demands for a greater variety of products and sizes.

[0005]

[Problems to be Solved by the Invention] In the conventional method, as mentioned above, the roll body length is fixed or constant for each roll, so it is necessary to prepare rolling rolls according to the rolling size. is huge,
■ The operating efficiency is significantly reduced due to the rearranging of rolls, and due to roll wear during rolling, ■ variations in product dimensions occur, and ■ the same rolling rolls of the same size cannot be used repeatedly for a long period of time, etc. There's a problem.

The present invention was made to solve the above problems, and without increasing the number of rolls held,
The purpose of the present invention is to provide a method for rolling H-beam steel in which the web height can be freely adjusted with good workability while ensuring high quality and high yield without reducing operation rate and rolling efficiency. .

[0007]

[Means for Solving the Problems] According to the present invention, the above object is achieved by a breakdown rolling mill, a roughing universal rolling mill,
Two rolling annular sleeves are fitted coaxially to the roll shaft and rotatable integrally with the roll shaft on the rear surface of the edging mill of a normal H-beam hot rolling facility consisting of an edging rolling mill and a finishing universal rolling mill. At the same time, a rolling mill having a pair of upper and lower rolling rolls each having at least one of the annular sleeves movable in the roll axis direction is installed nearby, and a coarse universal rolling mill is installed at the rear of the rolling mill. In a method of rolling H-section steel using rolling equipment equipped with a rolling mill equipped with a pair of upper and lower rolling rolls that are approximately barrel-shaped in shape and have a roll width that is less than or equal to the horizontal roll width, the roll width is fixed. The material to be rolled is rolled into an approximately H-shape by a down rolling mill, and is then rolled into a regular universal mill using rolls of a rough universal rolling mill and an edging mill, which are shaped to allow extra thickness to be formed at the flange, the web root, and both ends of the web. The step of rolling is repeated to reduce the thickness of the flange and web and control the flange width, and to form extra thickness near the base of the flange and web and at both ends of the web, and the rolled material that has been subjected to rough universal rolling is subjected to the edging rolling. A rolling mill equipped with a roll with a variable width installed at the rear of the machine is used to set the width of the roll to be larger than the width of the horizontal rolls of the rough universal rolling mill, thereby creating a mechanical web due to the difference in roll width. In one pass of rolling, most of the area reduction is converted into an increase in the inner width of the web by expanding the inner width of the web and rolling the excess thickness until it becomes the same thickness as the center part of the web in the final pass of rough universal rolling. This can be achieved by performing multiple passes while setting the roll width to be larger.

[0008]

[Operation] As described above, in the present invention, first, a rough universal rolling mill is used to form excess thickness at the base of the flange and the web and at both ends of the web. Following this step, in a rolling mill equipped with a pair of upper and lower roll rolls whose roll width can be adjusted, the width of the rolls is set larger than the inner width of the web in the above process, and rolling is performed to create a mechanical web due to the difference in roll width. Along with the expansion of the inner width, a step is performed in which most of the area reduction is converted into an increase in the inner width of the web by reducing the excess thickness formed in the above step to the same thickness as the center portion of the web in the above step.

[0009] By appropriately repeating these two steps, a predetermined web height can be obtained.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4 of the accompanying drawings.

FIG. 1 is a diagram showing the outline steps of the present invention.
Edging rolling is omitted for ease of understanding. Further, FIG. 2 shows a rolling mill arrangement for implementing the present invention, and in the figure, the second rough rolling mill group R2 includes a second rough universal rolling mill RU2, a second edging rolling mill RE2, and a second edging rolling mill immediately adjacent to the rear surface. A pair of upper and lower rolling rolls are mounted on the roll shaft, in which two rolling annular sleeves are fitted coaxially and rotatably together with the roll shaft, and at least one of the annular sleeves is formed to be movable in the roll axis direction. A total of three rolling mills, RY1, are installed.

In FIG. 1, state (a) is approximately H in the breakdown rolling mill BD or the first rough universal rolling mill RU1 and the first edging rolling mill RE1 shown in the figure.
The figure shows a state in which the material to be rolled into a shape has been rolled several passes by the second rough universal rolling mill RU2 and the second edging rolling mill RE2. This rolled material 1a consists of a horizontal roll 11h with a fixed width of roll width LH11 and a vertical roll 1.
Since it is rolled using 1v, the inner width of the web LH12
is approximately equal to the roll width LH11. Further, the roll end of the horizontal roll 11h is shaped to form extra thickness at the flange of the rolled material 1a, the root of the web, and both ends of the web, so that the rolled material 1a shown in state (a) in FIG. It is rolled into the shape of . Excess thickness amounts a and b shown in Figure 3
is determined in consideration of the amount of expansion of the inner width of the web in the subsequent process (for example, states (b) and (c) in FIG. 1) and the stability of rolling.

<First Embodiment> The inner width of the web of the material to be rolled 1a in state (a) in FIG. A rolling mill (RY1 in Fig. 2) is equipped with a pair of upper and lower rolls that are coaxially fitted to the roll shaft so as to be rotatable together with the roll shaft, and at least one of the annular sleeves is movable in the roll axis direction. State (c) in FIG. 1 shows the case where the process is performed using only one pass.

Rolled material 1a in state (a) in FIG.
A situation in which the inner width of the web is rolled by the rolling mill RY1 installed close to the rear surface of the second edging mill is shown in state (b) in FIG. First, set the width (roll width) of the rolling annular sleeve 12 of the RY1 rolling mill to LH31.
>LH11, and the rolled material 1a that has undergone rough universal rolling is rolled. RY1 in Fig. 2 The roll width difference (L
H31-LH11) mechanically stretches the web. Then, the extra thickness of the web is rolled into an annular sleeve 1.
By rolling with No. 2 (rolling roll), most of the area reduction of the excess thickness is converted into an increase in the inner width of the web. In this case, vertical rolls are used like in universal rolling, and flanges are not rolled.The reason is that the elongation in the length direction (rolling direction) due to rolling of the extra web part is controlled by the flanges, and most of the area reduction is This is to convert this into expanding the width of the web. In addition, to form excess thickness at both ends of the web as shown in state (a) in Figure 1, it is better to roll down the excess thickness at both ends of the web than to roll the excess thickness at the center of the web. This is because buckling of the web due to a difference in elongation in the longitudinal direction caused by a difference in rolling reduction of each part of the cross section can be easily prevented. Furthermore, the stretching of the web in the width direction due to the roll width difference is also very effective in preventing web buckling because force acts in the web width direction, and therefore the web buckles when the internal web width of the rolled material 1c is LH32. It will be expanded without any problem. In addition, the roll gap for rolling of this extra thickness portion is set so as to be equal to the thickness t11 of the central portion of the web upon completion of the rough universal rolling in state (a) in FIG. After the above process, the rolled material 1c is subjected to finish rolling as shown in state (g) in FIG. This finishing rolling mill FU is a universal rolling mill consisting of a horizontal roll 13h with a variable roll width and a vertical roll 13v, which has the same structure as the rolling roll 12 of the RY1 rolling mill, and the roll width LHF of the horizontal roll 13h is It is determined by taking into consideration the amount of thermal contraction of the inner width LH. In this case, finish rolling is mainly performed to raise the angle of the flange, and there is almost no reduction in the web. Therefore, the web thickness t1 of 1 g of material to be rolled is approximately equal to t11.

<Second Embodiment> When the amount of increase in the inner width of the web is made larger than in the case of the first embodiment, as described above, the flange and the base portion of the web and the web in the state (a) in FIG. It is necessary to increase the amount of excess thickness at both ends (a and b in FIG. 3). If this large excess thickness is used to expand the inner width of the web in one pass using the RY1 rolling mill as in the first embodiment, the rolling reaction force will increase, and the rolling reduction rate within the cross section of the rolled material 1c will increase. As the difference becomes larger, the difference in elongation in the longitudinal direction due to warping becomes larger, and there is a possibility that the web may buckle. In order to prevent this, it is effective to carry out reciprocating rolling using the RY1 rolling mill shown in FIG. 2, and to divide and roll the excess thickness of the web. An example of this is shown in states (a), (b), and (c) of FIG. First, the rolled material 1a that has been subjected to rough universal rolling shown in state (a) in Figure 1 is rolled down to the extent that web buckling does not occur, as shown in state (b) in Figure 1. . In this case, the width LH21 of the annular rolling sleeve 12 is LH21
>LH11. As a result, as described above, due to the roll width difference and the reduction of the excess thickness, the inner web width of the rolled material 1b becomes the inner width LH1 of 1a.
2 will be enlarged to LH22. Furthermore, in the next pass, the width of the rolling annular sleeve 12 of the RY1 rolling mill is set to LH31, which is wider than the web inner width LH22 of the previously rolled material 1b, and the excess thickness remaining in the rolled material 1b is set to the center of the web. Thickness t11
Roll until . As a result, the inner width of the web is LH32.
will be expanded to. After completion of this step, finish rolling shown in state (g) in FIG. 1 is performed as described above.

<Third Embodiment> This is a rolling method that expands the inner width of the web even more than in the second embodiment described above, and an example of this is shown in states (a) to (f) in FIG. explain. First, the initial expansion of the inner web width is as described above, as shown in Figure 1.
Follow the steps in states (a), (b), and (c). However, although the thickness t11 of the central portion of the web was approximately equal to t1 in the finish rolling in both of the above-mentioned <First Example> and <Second Example>, in this example, t11>t1. Rolled material 1 after the process up to state (c) in Figure 1 has been completed
c is rolled using a rough universal rolling mill RU2 so that the center thickness of the web becomes t12. In this case, the web thickness t12 is approximately equal to the web thickness t1 of 1 g of finish-rolled material. In addition, this rolling is performed in the state (c) of the previous step.
Since the inner width of the web is expanded up to, it is larger than the width LH11 of the horizontal roll 11h of the rough universal rolling mill RU2. Therefore, as shown in state (d) in FIG. 1, it is necessary to provide a gap between the vertical roll and the side wall of the horizontal roll 11h so that the flange cannot be rolled down. As a result of this rolling, excess thickness is again formed at both ends of the web, as shown in state (d) in FIG. This rolled material 1d is rolled as shown in the states (e) and (f) in FIG. 1 in the same manner as described above. In this case, the roll width LH61 of the RY1 rolling mill is LH61>L
It goes without saying that the condition is set as H51>LH42. After completion of the steps up to state (f) in FIG. 1, finish rolling shown in state (g) in FIG. 1 similar to that described above is performed.

FIG. 4 shows an example of how the rolling mill is operated in each of the above steps. The circle mark in the figure indicates rolling down.

[0018]

As described above, according to the present invention, extra thickness is formed near the base of the flange of the H-section steel and the web and at both ends of the web, and when the extra thickness is rolled, the inner width of the preceding web is By setting the roll width larger, most of the reduction in area due to mechanical stretching and reduction of excess thickness due to the difference in roll width can be converted into an increase in web height by combining with the roll width, so the inner width of the web can be reduced. (Web height) The enlarging effect is large, and there is almost no risk of web buckling due to the difference in rolling reduction ratio.■ The web height can be freely adjusted with a small number of passes, resulting in high rolling efficiency. ■ Since the effect of expanding the inner width of the web is large, it is possible to use the same rolling roll for various sizes with different web heights, so there is no need to increase the number of rolls owned as the size increases. There is no risk of product defects such as bending, and the dimensional control accuracy is constant over the entire length of the rolled material.■ As a result, high quality and high yield manufacturing can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the steps of the rolling method of the present invention.

FIG. 2 is a sectional view of a rolling mill arrangement, rolls, and H-section steel for carrying out the present invention.

FIG. 3 is a diagram showing the shape of the flange formed at the completion of rough universal rolling, the shape of the excess thickness near the root of the web, and at both ends of the web.

FIG. 4 is a diagram showing an example of a method of operating a rolling mill in each process of the present invention.

FIG. 5 is a sectional view showing a conventional rolling process for H-section steel, the configuration of rolling rolls of each rolling mill, and the shape of a rolled material.

FIG. 6 is a cross-sectional view showing the dimensional relationship of H-beam steel.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d, 1e, 1f, 1g Material to be rolled 11h Horizontal roll 11v of rough universal rolling mill
Vertical roll 12 of the rough universal rolling mill RY1 Rolling annular sleeve 13 of the rolling mill RY2 Approximately barrel-shaped horizontal roll BD of the rolling mill Breakdown rolling mill R1 First rough rolling mill group R2 Second rough rolling mill group F Finishing rolling mill RE1 First edging rolling mill RU1 First roughing universal rolling mill RU2 Second roughing universal rolling mill RE2 Second edging rolling mill RY1 Two rolling annular sleeves are fitted to the roll shaft coaxially and rotatably together with the roll shaft. A rolling mill FU is equipped with a pair of upper and lower rolling rolls each having at least one of the annular sleeves movable in the roll axis direction. Finishing universal rolling mills LH11, LH21, LH31, LH51, LH61,
LHF roll width LH12, LH22, LH32, LH42, LH52,
LH62, inner web width of H-beam steel

Claims (3)

[Claims] Claim 1: Two rolling mills are installed on the roll axis at the rear of the edging mill of a normal hot rolling facility for H-section steel consisting of a breakdown rolling mill, a rough universal rolling mill, an edging rolling mill, and a finishing universal rolling mill. A rolling mill in which a pair of upper and lower rolling rolls each having an annular sleeve fitted coaxially and rotatably with the roll shaft and at least one of the annular sleeves movable in the direction of the roll axis is installed in close proximity. The rolling mill is equipped with a pair of upper and lower rolling rolls installed on the rear surface of the rolling mill, each having a roll width less than the horizontal roll width of the rough universal rolling mill, the shape of which is roughly barrel-shaped, and the roll width being fixed. In the method of rolling H-beam steel using a rolling equipment equipped with a rolling machine, the material to be rolled is rolled into a substantially H shape by a breakdown rolling machine, and the material is shaped so that excess thickness can be formed at the base of the flange, the web, and both ends of the web. Regular universal rolling is performed using the rolls of a rough universal rolling mill and an edging rolling mill to repeatedly reduce the thickness of the flange and web and control the flange width, and to form excess thickness near the base of the flange and web and at both ends of the web. The rolled material, which has undergone rough universal rolling, is rolled in a rolling mill equipped with a roll with a variable width installed at the rear of the edging mill, where the width of the roll is greater than the width of the horizontal roll of the rough universal rolling mill. By rolling with a larger setting, the inner width of the web is mechanically expanded due to the roll width difference, and the area is reduced by rolling the extra thickness until it becomes the same thickness as the center of the web in the final pass of rough universal rolling. 1. A method for rolling an H-section steel, comprising the step of carrying out one pass of rolling to convert most of the rolling amount into an enlargement of the inner width of the web, or a step of carrying out multiple passes while setting the roll width to be larger. [Claim 2] After completing the rolling process according to claim 1,
Using the rough universal rolling mill again, open the roll gap between the vertical roll and horizontal roll side wall so as not to roll down the flange part, and roll the web of the material to be rolled using only the upper and lower horizontal rolls.
A step of reducing the thickness of the web and forming extra thickness at both ends of the web, followed by a rolling mill installed at the rear of an edging mill incorporating rolls with variable roll widths to reduce the inner width of the web at the previous stage. By rolling with a larger roll width, the inner width of the web is mechanically expanded due to the difference in roll width, and the extra thickness is rolled to the same thickness as the center of the web in the previous stage. The rolling step converts most of the area reduction into an increase in the inner width of the web.
A method of rolling H-section steel that involves one pass or several passes. 3. Two rolling annular sleeves are fitted coaxially and rotatably together with the roll shaft, and
In a finishing universal rolling mill having a horizontal roll in which at least one of the annular sleeves is movable in the roll axis direction, the outer width between the two annular sleeves of the horizontal roll is adjusted and set to match the inner width of the web of the material to be rolled. The method for rolling an H-section steel according to claim 1 or 2, wherein the H-section steel is subjected to finish rolling.