JPH03142002A - Method for rolling h-shaped steel - Google Patents

Abstract

PURPOSE:To improve the accuracy of the web height of the H-shaped steel and to reduce the consumption unit of rolls by installing web height rolling mills to a universal finishing mill for the H-shaped steel and adjusting the web height together with shape finish rolling. CONSTITUTION:The web height adjusting device 10 is constituted by axially bisecting upper and lower horizontal rolls 1 in such a manner that the respective horizontal rolls 1 can be adjusted and moved in the axial direction. Since the H-shaped steel 4 is rolled by restraining the flanges thereof between vertical rolls 2 and respective horizontal rolls 1, the web height is precisely regulated. The shaping of the inclination of the flange opening and the change of the web height are executed by the web height adjusting device to be directly installed to the universal finishing mill. As a result, the web height H can be confined within a prescribed tolerance range. There is no need for increasing the flange thickness by the expansion of an internal width and, therefore, the rolling yield thereof is improved and further the width of using the horizontal rolls is expanded.

Description

[Detailed description of the invention] The present invention relates to a method for rolling H-section steel.

Conventionally, in universal rolling of H-beams, the inner width allowance of the horizontal rolls was determined within the dimensional tolerances of web height and flange thickness, and by this, H-beams with variations within the web height tolerance range were manufactured. Was. That is, as shown in Figures 1 and 2, the internal width W of the horizontal roll is determined by the product dimensions web height 01) and its tolerance (±ΔH), and flange thickness (L2) and its tolerance (±Δh). The relationship is as follows.

Wmax = δ'((H+ΔH)-2(t2-Δtz)
δ)-PWmin= δ' ((H-ΔH)-2
(M2+Δtz) δ)-P However, Wmax: Maximum internal width of the horizontal roll Wm1n: Minimum internal width of the horizontal roll δ': Web internal width hot shrinkage allowance δ: Flange thickness hot shrinkage allowance P: Margin allowance tz: Flange thickness Therefore, the inner width usage allowance Δ of the horizontal roll is determined from the following equation.

Δ=Wmax-Wmin This inner width usage allowance is 3 to 4 from the relationship between product yield, roll unit consumption (roll wear amount/rolling quality N), and web height accuracy.
mm is common. The variation in web height of actual products can be reduced to some extent by adjusting the flange thickness, but the maximum variation is about 2 to 2.5 W. If precision of the web height H is required, horizontal rolls that match the precision must be prepared and manufactured.

In the construction industry, when using rolled H-section steel, the accuracy of the web height is poor, so it is necessary to measure the actual product each time and perform on-site work.

Conventionally, IJ sections were manufactured based on the internal method standard for web height, but due to the user's request for ease of use, the method for manufacturing section steel (JP-A-57-1998) with an external method of Ml + 1.50
No. 1) has been proposed. However, it is common practice to modify rolls one after another for large or small dimensions, and when it comes to rolls for a certain dimension, the problem method varies depending on how much the product can be rolled with that dimension. It was.

As a roll width variable roll, for example, Japanese Patent Application Laid-Open No. 524995
Assembly rolls such as No. 7 have been proposed.

This involves assembling a disc-shaped roll and a spacer onto a roll shaft, and by replacing the spacers with various types, the roll width can be changed. However, when rolled with this roll, the roll joint circular portion was transferred to the web surface, resulting in streak-like rolling defects, and it was not possible to replace the front rolling roll.

Therefore, an object of the present invention is to improve the accuracy of the web height of H-section steel, and to increase the allowance for the inner width of horizontal rolls, thereby reducing the roll consumption rate and improving the rolling yield. The object of the present invention is to obtain a method for rolling section II steel using split rolls.

The rolling method of the present invention uses a finishing uniparser characteristic of H-beam steel.

In universal rolling of Hl, depending on the horizontal roll width of a certain roll chance, there is an inversely proportional relationship between the flange thickness t2 and web height H of the H-section steel, as shown in Figure 3, and it is within the tolerance range. It was manufactured in In order to improve this, the web height is constrained in rolling using a web height adjusting device.

The web height adjustment device 10, as shown in FIG.
The upper and lower horizontal rolls 1 are divided into two in the axial direction, and each horizontal roll 1 is configured to be adjustable and moveable in the axial direction. As shown in the figure, the flange of the H-section steel 4 is rolled while being restrained between the vertical roll 2 and each horizontal roll 1, so the height of the web is precisely regulated.

The web height adjustment device, which is installed directly on the finishing universal mill, not only shapes the flange opening slope (finish rolling to make the flange perpendicular to the web), but also changes the web height (shapes the web at the center of the outside of the flange). Perform web height restraint rolling to reduce or expand the height.

According to experiments, the amount of reduction possible in the web height constraint rolling at this time falls within the shaded range shown in FIG. When decreasing the web height H of H-section steel, the web height reduction rate ψ8 becomes positive and buckling occurs in the web outside the shaded area, and when increasing the web height H, the web height reduction rate ψ8 becomes positive. ψH is negative, and outside the shaded area, dents and web thinning on the outside of the flange will cause problems. From this, in the case of H-section steel of normal dimensions, the limit for web height H4Pl adjustment is about 2.5M.

As a result, the web height H is 1ΔHl+nax≦l mm
It can be paid to. In addition, since the flange thickness does not need to be increased by increasing the inner width, the rolling yield is improved accordingly.
Furthermore, the usable width of the horizontal roll can be expanded by more than 1.5 times compared to the conventional method.

Next, with reference to FIGS. 6 and 7, a web height adjusting device 10 that implements the rolling method of the present invention will be described. The web height adjustment device 10 is made up of a horizontal roll 1 and a vertical roll 2. The vertical roll 2 that rolls the H-shaped flange 41 from the outside is the same as the conventional one. The horizontal roll 1 is divided into two in the axial direction and configured to be movable in the axial direction, and rolls the inside of the flange 41 while holding the web 42 of the H-beam 4.

The horizontal roll 1 is a feature of the present invention, and its details are shown in FIG. The horizontal roll 1 is made by inserting a plurality of spacers 12 of an appropriate width into the center of the arm μ 11, fitting roll rings 13 on both sides of the spacers, and inserting collars 14 of an appropriate width on both sides of the spacers 12. It has a structure in which it is tightened with 5 cross-sections.

The width of the spacer 12, roll and
The outer diameter of the ring 13 and the width of the collar 14 are determined.

Such dimensional recombination may be performed at the same time as the roll recombination of each universal short length, prior to the start of rolling of H-beams of various sizes.

The results obtained by the rolling method of the present invention are shown in Figure 8 (not shown).

(8) The figure shows the relationship between the horizontal roll usage allowance, the dimensional tolerance ΔH of the web height H, and the dimensional tolerance Δt2 of the flange thickness L2. In the figure, the dashed-dotted line shows the results obtained by the method of the present invention, and the solid line shows the results obtained by the conventional method. (B)
The figure shows the relationship between the horizontal roll allowance and the rolling reduction ratio ψa of the web height adjusting device of the present invention.

As can be seen from FIG. 8, according to the rolling method of the present invention,
The amount of rolling that can be rolled per pair of finishing mill horizontal rolls is increased by more than 1.5 times.

[Brief explanation of the drawing]

Figure 1 is a partial front view of a conventional universal mill for H-section steel. FIG. 2 is an explanatory diagram showing the main dimensions of section 11 steel. FIG. 3 is a graph showing the relationship between the horizontal roll usage allowance, web height dimensional tolerance, and flange thickness dimensional tolerance according to the conventional method. FIG. 4 is an explanatory diagram showing the rolling force method of the present invention. FIG. 5 is a graph showing experimental results of the possible rolling reduction in web height restraint rolling. FIG. 6 is a front view of a web height adjusting device that implements the rolling method of the present invention. FIG. 7 is a longitudinal sectional view of a horizontal roll used in the web height adjustment device. FIG. 8 is a graph showing the effect of the rolling method of the present invention. 1: Horizontal roll 2: Vertical roll 4: H-shaped steel 10: Web height adjustment device 41:
Flange 42: Web (2 other people) tz 4 ply 2 Procedural amendment 1, 1990 1, October 2-7 1, Case indication 0 -: zlo32δゝ2, Title of invention Method for rolling H-beam steel 3. Relationship with the person making the amendment

Claims (1)

[Claims] A universal mill for finishing H-beam steel is equipped with a web height adjustment device equipped with a horizontal roll that is divided into two parts in the axial direction and can be moved in the axial direction to adjust the web height during shaping rolling. A method for rolling H-section steel, characterized by rolling.