JPH0366961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling a section steel and a rolling mill row thereof, which are employed when split sleeve type rolls are used as the horizontal rolls of a universal mill.

For example, a universal mill used for rough rolling H-section steel requires horizontal rolls with different roll widths for each series, and the number of rolls in stock is large because the worn parts on the side of the roll body must be ground and reused. Become something. For this reason, various horizontal rolls have been proposed in which the sleeve to be fitted into the arbor is divided into a plurality of parts in the axial direction, and the divided sleeves are integrated using various methods so that the width can be adjusted.

A problem with such a split sleeve type roll is the joint between the split sleeves. In other words, it is a contact between rigid bodies,
It is possible to eliminate gaps by finishing the contact surfaces, but it is difficult to completely eliminate gaps because sleeves require compatibility and are subject to wear.
The seam portion widens due to the rolling load, and thorn-like protrusions 1 as shown in FIG. 1A are generated in the portion of the web rolled at this portion. When a web having such projections 1 is rolled, lap flaws 2 as shown in FIG. 1C will occur. Such lap defects 2 are serious defects and cannot be used as products.

This invention was proposed in view of the above circumstances, and its purpose is to provide a method for rolling steel sections that uses split sleeve type rolls to obtain a smooth web surface without generating thorn-like protrusions. and its rolling mill train.

The method for rolling a section steel according to the present invention uses split sleeve type rolls in which outer circumferential division seam portions of upper and lower horizontal rolls of a universal mill correspond to each other, and concave grooves are formed in these portions. After rolling the material to be rolled, the material having the gentle convex portions formed by the concave grooves is rolled down by the next horizontal roll to form a smooth web surface.

A rolling mill row for rolling shaped steel according to the present invention includes a universal mill having a split sleeve type horizontal roll in which a concave groove having a width of half or less of the roll body width is formed at the seam of the roll outer periphery division part; It consists of an edger mill having an edger roll capable of rolling down the entire width of the convex portion of the shaped steel web surface formed by the groove, and is designed to obtain a smooth web surface with a relatively simple improvement.

The split-sleeve type horizontal roll uses, for example, a roll in which the arbor is covered with an intermediate sleeve that can be expanded and contracted by fluid pressure between the arbor and the split sleeve.

This will be explained in more detail below based on the figures.

As shown in Figure 2, the upper and lower horizontal rolls of the universal mill for rough rolling are divided into three sleeves 1
0, 11, and 12 are attached to the arbor 13, and the joint portions (sleeve joints) of the respective outer circumferential divisions correspond to each other. A concave groove 14 is formed around the seam on the outer periphery of this portion.

This concave groove 14 is shaped to form a gentle convex portion 15 on the web surface of the section steel, and its width is 1/2 or less of the roll body width, and its depth is 1/2 of the roll reduction amount. It is preferable to set it to about 1/3, and the shape may be trapezoidal or arcuate.

In the rough rolling of shaped steel, horizontal rolls reduce the thickness of the web surface, and horizontal rolls and vertical rolls reduce the thickness of the flange surface. This will result in an extension to. Here, if a local concave groove is provided in the horizontal roll, an unrolled part will be generated, but if the width of the groove is less than the other rolled part, a thinning effect will occur due to the elongation of the section steel. Its cross-sectional shape is a gentle convex portion. The height varies depending on the groove width, but is approximately 1/2 to 1/3 of the reduction amount.

Note that the gentle convex portion formed on the web surface is a raised shape that does not cause folding during the next stage of rolling, and the roll shape has a concave groove continuing to the body that is in contact with the rolled material. This can be achieved by forming a gently sloped surface or by chamfering an arc.

A convex portion 15 is formed on the web surface of the H-shaped steel rolled by such a split sleeve type horizontal roll, but this convex portion 15 is rolled down by the edger roll 16 in the next stage to smooth the web surface. Make it. That is, in a normal edger mill, only the flange ends are etched, but as shown in FIG. 3, the center part of the edger roll 16 is configured to come into contact with the web surface, and the convex part 15 is rolled down at the same time as the edger mill. .

Normally, rough rolling of section steel is carried out as shown in Fig. 4.
A universal mill and an edger mill are installed adjacent to each other, and a group of rolling mills reciprocates the rough shaped material multiple times to shape it into a product shaped steel. The shaped steel material with convex portions formed on the web surface by the universal mill is immediately turned into a smooth web surface by the edger mill in the subsequent stage, and is rolled at least two passes in the universal mill and one pass in the edger mill.

Next, what is shown in FIG. 5 is a split sleeve type horizontal roll in which one concave groove 17 is formed.
This is achieved by making the outer diameter of the central sleeve 11 match the root diameter of the concave groove 14. In this case, the edger roll is the same roller as edger roll 16 shown in FIG.

Next, as a method for fixing the sleeve of the above-mentioned split sleeve type horizontal roll, a double sleeve method as shown in FIG. 7 is suitable. That is, an intermediate sleeve 18 is provided between the sleeves 10, 11, 12 and the arbor 13, and a hydraulic chamber 19 is provided between the intermediate sleeve 18 and the arbor 13. Joint 2
1. A nonflammable liquid is supplied through the communication hole 22 to inflate the intermediate sleeve 18 in the radial direction, thereby fixing the sleeves 10, 11, and 12.

Removal of the sleeves 10, 11, 12 or adjustment of their position is facilitated by reducing the pressure of the supply liquid.

Example A steel section of product H400 x 400 x 13/21 was rolled in a rolling mill line consisting of a double breakdown mill, a rough universal mill, a rough edger mill, a finishing universal mill, and a finishing edger mill.

The sleeve 12 with a thickness of 150 mm and the central sleeve 11 with a thickness of 58 mm are assembled on the horizontal roll of the rough universal mill as shown in Fig. 5, and the inner corners of both sleeves 12 are chamfered at 4C. A concave groove 17 with a width of 66 mm and a depth of 4 mm was formed. The rough edger mill after this rough universal mill has horizontal rolls as shown in Figure 6.
A 220mm wide web surface pressure lower part was provided in the center.

Web height 560 with double breakdown mill
After shaping a beam blank material with a web thickness of 79 mm, it was reciprocated in 13 passes using the rough universal mill and rough edger mill described above, and the web height was
It was made into a rough H-beam steel with a diameter of 403.4 mm, a web thickness of 13.6 mm, and a flange thickness of 22.7 mm, and was rolled to product dimensions in one pass using a finishing universal mill and a finishing edger mill.

During rough universal rolling, the maximum reduction on the web surface was 10.2 mm, but the measurement results of the sample material during rolling confirmed that the maximum thickness of the convex part was 7.6 mm thicker than the other web surfaces. did it. Although it was confirmed by visual appearance that some of the protrusions were in contact with the groove bottom, there were no harmful protrusions, and the protrusions had a smooth shape. Furthermore, the product dimensions after finish rolling were within tolerances, and there were no harmful flaws on the web surface.

As described above, according to the rolling method of the present invention, a smooth web surface can be obtained without generating thorn-like protrusions while using a split sleeve type roll, and the rolling quality can be improved. Also,
By adjusting the roll width dimension by combining the sleeves of the split sleeve type roll, there is no need to prepare horizontal rolls with different roll widths as in the past, and the roll consumption rate can be reduced.

Further, according to the rolling mill row according to the present invention, split sleeve type rolls with improved outer peripheral split seam portions are used as the horizontal rolls of the universal mill,
In addition, by using edger rolls for the next stage of rolling, existing rolling mill rows can be used as is with minimal modification of equipment, and together with a reduction in roll consumption, equipment costs are reduced. Moreover, the above-described rolling method can be carried out reliably.

[Brief explanation of drawings]

1A, B, and C are schematic cross-sectional views showing the occurrence of folding defects in the conventional method; FIG. 2 is a cross-sectional view showing a universal mill of a rolling mill according to the present invention;
The figure is a sectional view showing a similar Edger mill, Figure 4 is a perspective view of a similar rolling mill row, Figures 5 and 6 are sectional views showing modifications of the universal mill and Edger mill, and Figure 7 is a fixing of the sleeve. It is a sectional view showing a means. 1...Protrusion, 2...Lap flaw, 10, 11, 12...
Sleeve, 13... Arbor, 14... Concave groove, 15...
Convex portion, 16... Edger roll, 17... Concave groove,
18... Intermediate sleeve, 19... Hydraulic pressure chamber, 20... Pressurizing device, 21... Rotary joint, 22... Communication hole.

Claims (1)

[Scope of Claims] 1. A material to be rolled is rolled using a split sleeve type roll in which outer circumferential division seam portions of the upper and lower horizontal rolls of a universal mill correspond to each other, and concave grooves are formed in these portions. A method for rolling a section steel, characterized in that after rolling, the material to be rolled having a gentle convex portion formed by the concave groove is rolled down by a horizontal roll in the next stage to obtain a smooth web surface. 2. A universal mill having a split sleeve type horizontal roll in which a concave groove having a width of less than half of the roll body width is formed at the seam of the roll outer circumference division, and a shape steel web surface formed by the concave groove. 1. A rolling mill train for rolling section steel, comprising: an edger mill having edger rolls capable of rolling down the entire width of the convex portion. 3. The split sleeve type horizontal roll consists of a split sleeve on the outer periphery, an intermediate sleeve and an arbor in contact with the split sleeve, and the intermediate sleeve can expand and contract in the radial direction by the fluid pressure in the hydraulic chamber provided between the intermediate sleeve and the arbor. A rolling mill train for rolling shaped steel according to claim 2.