JPS61108404A - Rolling method of sections with flange - Google Patents

Abstract

PURPOSE:To improve product quality by slanting each roll axis by a prescribed angle thetaH with respect to the surface perpendicular to rolling direction and providing a taper surface, maintaining surface contact with the inside surface of a flange of rolling stock, to each roll. CONSTITUTION:Both pairs of skew rolls 15, 15' and 16, 16' are provided to the upper and lower sides, and their axes are slanted each, by prescribed angle thetaH with respect to the surface perpendicular to rolling direction in the horizontal plane, and by an angle thetaV with respect to the horizontal axis in the horizontal plane. Further, taper surfaces of about gamma=10 deg. are provided to respective rolls 15, 16. At that time, the taper angle gamma is decided in relation to the angle thetaV, and the taper surface 10 is brought into surface contact with the inside surface of the flange of a stock 17 to be rolled when skew rolling is performed. Accordingly, the generation of rubbing flaws is prevented, and the product yield is improved, by using these rolls for skew rolling.

Description

[Detailed description of the invention] (Industrial application field) The invention relates to a profile with a flange, ie.

I+A is applied to the rolling force method, which freely creates various sizes of H-shaped and similar shaped products in the rolling process.

(Prior Art) Shapes currently manufactured have a wide variety of types, cross-sectional shapes, and dimensions, and are characterized by an extremely large number of types and sizes. In order to manufacture these various types and sizes of shapes, F! In the known conventional rolling method, rolling rolls corresponding to a large number of groove shapes as shown in FIGS. 2(a) and 2(b) are required depending on the shape. As a result, the number of roll changes increases, which increases time loss and significantly reduces productivity.

Fig. 2(a) shows an example in which two-type or triple-type rolling mills are arranged from rough rolling to finish rolling, and I-shaped steel and channel steel are rolled by these rolling mills, and Fig. 2(b) This shows an example in which double or triple rolling mills are arranged for rough rolling, and universal rolling mills are arranged for intermediate rolling and finishing rolling, and H-shaped steel and channel steel are rolled using these rolling mills.

In the conventional rolling method as shown in Figure 2, rolling rolls and kites as accessories are used from rough rolling to finish rolling according to the type and size of the product to be manufactured. Therefore, in order to satisfy customer needs such as diversification of product dimensions and expansion of manufacturing range, it becomes costly and cannot be easily accommodated. .

As a specific example, the case of H-beam steel will be described below. With recent advances in welding methods, steel plates are now being manufactured by welding and assembling them together. Production of so-called built-amp H-beam steel is increasing. The reason for this is that H-shaped steel products of any size can be manufactured freely according to needs. Typical examples include H-beam steel whose web thickness is relatively thin compared to the thickness produced by conventional rolling methods, or H-beam product series with various flange H widths that keep the outer width of the web constant. It is something like that.

When used as beam members, H-beam steel with various flange thicknesses and a constant external width of the web are advantageous for joining between beams. The reason why it is not manufactured is as follows.

FIG. 3(a) shows a typical example of a conventional H-section steel rolling equipment row, in which one breakdown rolling mill 1 (
BD),, followed by 40-mill universal rolling #1 (RU) and Edger rolling mill (E) group 2 (RU-
E), Finishing 4 o-Ruyu-Parsal rolling mill 3 (F
U).

FIG. 3(b) shows each rolling mill 1°2 in FIG. 3(a).
Figure i4 shows the shape of each rolled material 4°5.6 formed in step 3, and shows the relationship between the rolling rolls and the rolled material in the uniform rolling method for rolling H-beam steel. , due to the function of the universal rolling mill, the dimensions that can be freely changed between the same set of roll pairs during rolling are the upper horizontal roll 7.
There is only a gap 9 between the lower horizontal roll 8 and a gap 12.13 between the left and right vertical rolls 10.11. Therefore, although the web thickness 9 and the flange thickness 12.13 of the H-section steel can be changed, the inner web width IW must remain constant.As a result, the thickness 9 of the H-section steel products is different in series. When rolling, if the left and right flange thickness 12.13 is changed, the web outside @OW which is the sum of the web inner width IW and the left and right flange thickness 12.13 is naturally
must change to various dimensions.

That is, as shown in FIG. 5, H-section steel rolled by the conventional rolling method has a constant web inner width IW and a flange thickness T.
By changing f,, Tf2, the web outer width ow,, ow2
This results in a series of products with a constant inner web width, where the inner width of the web changes, and it is difficult to manufacture a series of products with a constant outer width of the web. If you want to manufacture an H-section steel product series with a constant outer web width oW using a conventional rolling method using a universal rolling mill.

Most of the upper and lower horizontal rolls in all processes from rough rolling to intermediate rolling to top rolling must be prepared according to changes in the inner width of the web, which requires a large number of rolls and frequent reshuffling of the rolls. This results in a significant increase in manufacturing costs.

It is difficult to practically adopt this method.

(Problems to be Solved by the Invention) The present invention solves the drawbacks of the conventional method and effectively produces different sizes of section steel. ``Method for Rolling Shapes with Shapes'' (Special Crime 1987-77391) attempts to provide an optimal roll shape that is indispensable for manufacturing good products without causing rolling defects in the products.

Before entering into a detailed description of the present invention, an outline of the "oblique roll rolling method" will first be explained using rolling of H-beam steel as an example. The feature of this rolling method is that, as shown in FIGS. 1(a) and (b), two upper and lower oblique rolls 15, 15' and IB, 18' are in contact with the inside of the flange of the material 17, and The roll axis rolls down the web part close to the flange of the material while maintaining an angle of θ with the rolling direction in the horizontal plane, and θ with the horizontal axis in the horizontal plane, so that the rolled part of the material is rolled in the width direction. It has the function of allowing the web to flow in the width direction and spreading the web in the width direction without causing any web waves or the like.

Figure 6 CB) shows an example in which a rolling mill 14 employing this "oblique roll rolling method" is incorporated into a row of hot rolling equipment for H-section steel. -E
) 2 and “oblique roll rolling mill J 14 and finishing rolling &t
By combining (FU)3, we can meet the typical needs mentioned above, such as "H-beam steel product series with constant web outer width" or "H-beam steel product series with arbitrary web height" as shown in Figure (b). Basically, it becomes possible to manufacture with a small number of rolls.

Further, using the same figure, an example in which the present invention is applied to manufacturing a series of H-beam steel products with a constant web outer width OW will be explained in detail.

In the same figure, the specific roles of each rolling mill: intermediate universal rolling a (RU-E) 2, diagonal roll type signing mill (53) + 4, and finishing rolling mill (FU) 3 are shown using roll hole diagrams. It was shown. First, in intermediate universal rolling mill 2, B
The flange thickness, web thickness, and web inner width IW, , IW, ・
25.2 Cross-sectional shape as shown in the illustrated example with consideration of...
Continue modeling up to 6. Cross-sectional shape 2 formed in this way
5.28 The number of types is not limited; in other words, since the material is rolled and shaped by a universal rolling mill in an intermediate process, it is possible to freely change the web thickness and flange thickness. , a required number of different cross-sectional shapes are printed depending on the product series. The web inner width IW is constant, and the reweb outer width OW1 is not necessarily constant.

Cross-sectional shape 25 formed by intermediate universal rolling mill 2
, 28. Alternatively, the rolled material shaped into a cross-sectional shape in which the web thickness and the 7-lange thickness are further different as required is sent to the diagonal roll type rolling mill 14.

These rolled materials are each expanded into rolled materials 27 by diagonal roll rolling fi+4 to various necessary web inner width dimensions IW2 depending on the product series.

The rolled material 27 produced by the diagonal roll type sizing mill of the present invention is shaped into cross sections 28 with various inner web #MI W4 according to the product series by the finishing rolling mill 3, and the outer width of the web is constant. Product 29 also has an inner width ■W according to the product series. In addition, product 31, which has the largest 7-lunge thickness and the smallest inner web width in the product series, is subjected to finish rolling &'1 (FU) 3 directly to intermediate universal rolling fi ( It can be manufactured by using the cross sections 25 and 28 of RU-E)2. However, in this case,
The web inner width IW of the cross section 30 corresponds to the product web inner width IW.

and a cross section 25 of the intermediate universal rolling mill (RU-E) 2.
．． The inner width IW of 28 is set to a mutually compatible value.

In the case of this application example, the preparation and replacement of a large number of rolls and their accessories can be omitted by creating different web inner widths in the pre-finish rolling process. However, it is recommended that the horizontal rolls of the rolling mill be replaced with rolls that match the inner width of the web for each product with different inner web widths supplied from the previous process. This is the most preferable method for obtaining a product, but if the amount of change in the inner width of the web is small, it is possible to share the finishing roll, or by making the finishing roll a variable width type as shown in Figure 7, it is possible to replace the finishing roll. This can be omitted. The excellent web widening function of the ``oblique roll force type ratio rolling method'' and an example of its use when it is incorporated into a hot rolling equipment array have been explained using the case of rolling an H-section steel as an example. However, in this "oblique roll rolling method", if a roll with a cross-sectional shape as shown in FIG. 1(C)° is used, the results shown in FIGS.
As shown, scratches 4 occur on the inner surface of the flange of the H-section steel on the exit side of the roll. Therefore, in order to solve this problem and obtain a good product, it is necessary to use a tapered roll having a cross-sectional shape as shown in FIG. 1(d). This will be explained in detail in the following section.

(Means for Solving the Problems) The mechanism by which scratches occur due to Fl frictional contact between the flange of an H-section steel and a roll was investigated in a model rolling experiment using plasticine material. The scratches that we are trying to resolve are shown in Figure 8 (
As shown in a), the inventors have found that the scratches 4 are caused by a-rubbing contact when the inner width of the flange 1 is expanded by the roll 3 on the exit side of the roll 3. That is, this flaw is caused by the material on the surface layer of the flange flowing in the direction of rotation of the roll due to friction with the roll, as shown in FIG. 2(b). Therefore, the inventors aimed to reduce the contact pressure per medium area that acts on the material from the roll. It has also been found that this can be achieved by optimizing the roll shape. That is, FIG. 9(a) shows the flange 1 and roll 3 of the H-shaped material during rolling shown in FIG.
The contact state within the circles 5 and 6 in FIG. 3(a) is a schematic line contact state. For this reason, the pressure per unit area applied from the roll to the material has to be extremely large, and as a result, the corners of the disc-shaped roll dig into the surface of the material, causing it to break. It was found that a lot of scratches were generated.

As a result of studying methods for preventing the occurrence of flaws based on the flaw generation mechanism described above, it was thought that it would be effective to bring the contact state between the material and the roll into a state of wide-area contact. That is, for example, a roll as shown in FIG. 9(b) can be used to eliminate the gap 4 that occurs between the disc-shaped roll and the H-shaped material flange in FIG. 9(a). If the shape is made, the surface contact state should naturally be (1).Based on this idea, a roll shape with a taper lO of around γ:IO° as shown in Fig. 10(b) is determined, As a result of rolling using this roll, it was found that it was possible to recycle a product without defects as shown in FIG. 11(C).

Note that Figures 11 (a) and (b) show scratches caused by rolling using the roll with the cross section shown in Figure 10 (a); This was caused by rubbing at the corner 30.

Next, a specific method for determining the roll shape will be explained.

Rolling is stopped when the material is caught between the rolls, the anti-grip material in the middle of rolling is taken out, and the deformation of the material from the roll center to the roll exit is examined in detail.

The roll used in this case may be a roll having the cross-sectional shape shown in M2O diagram (a).

Using this anti-grip material, the optimal roll shape is determined in the following order. This will be explained using FIG. 12. First, i1
As shown in Figure 2 (a), a weir 3 is placed on the inner surface of the flange 1 of the material.
A mold of the deformed shape of the inner surface of the flange is taken by pouring the gypsum solution into the mold. This mold is placed on the automatic three-dimensional measuring machine shown in Figure 13(b) to read the coordinates, and then by converting these coordinates, a contour map for a plane perpendicular to the roll axis is created as shown in Figure 13. The optimum profile for the roll is determined based on this contour map, but the roll profile is determined by modifying the contour map in a direction that achieves greater deformation, taking into account the elastic recovery of the material immediately after rolling. .

Note that even if the geometric conditions during rolling, such as the roll spacing and cross angle 08 (see Figure 1), are varied within a practical range, the obtained roll contour diagram will remain the same. The roll shape (γ in FIG. 1O) determined from this has approximately the same value. That is, when Ov is 5°, extremely good surface contact can be achieved by setting γ to about 13@.

Regarding the angular changes of θ and γ, it is preferable to select a range of 21 to xs''o! in the range of γ-0.

In this way, by using a tapered roll, the contact area between the material and the roll is increased, the contact pressure between the two is also dispersed, and the occurrence of scratches is prevented.

In Fig. 14, a contour map for a plane perpendicular to the roll axis is obtained based on the anti-grip material rolled using a tapered roll with γ = 13°. It can be seen that a very steel plate-like contact can be obtained at the contact area between the material and the material.

Also, by comparing Figures 13 and 14,
It can be seen that the figure shows that one contour map is made up of extremely well-ordered layered curves. This indicates that no scratches were formed on the product. It should be noted that if the above-mentioned value of γ-θ is smaller than 2°, the contact range becomes narrow and the flaw prevention effect is significantly lost. Also, if the same value exceeds 15°, H
The flange of the profile (1 in Figure 8) is pushed outward and the shape is significantly damaged, so finishing rolling (6th step) is carried out following this rolling.
3) in the diagram is in good condition! Shape shaping with l;
It becomes f-ability.

(Function) The cross-sectional shape of the roll determined in the above procedure is
This is shown in Figure 0 (b). Figure (a) shows the cross-sectional shape of the roll before improvement. In these figures, 20 is a part that rolls down the web part of the H-shaped member, and 10 is a part that faces the 7 langes of the H-shaped member. Further, the angle indicated by 0 in FIG. 1 is the same as 0 in FIG. 1 described above, and corresponds to the inclination angle of the roll axis with respect to the y-axis.

In addition, the shaded area at 1O and 20 in FIGS. 10A and 20B is the area that comes into contact with the material during rolling. That is, in the roll shape of (a), the shape of the roll shown in FIG.
), the part 10 in Figure 1O(a) is made up of materials:
Corner 30, which is the boundary between 10 and 20 without touching
The inner surface of the 7-lunge of the H-shaped member will be strongly rubbed at this point.

In contrast, in FIG. 10(b), the wide portions 10 and 30 of the roll of FIG. 10(b) are in contact with the flange portion of the material.

Therefore, the pressure per area applied to the material from the rolls is distributed over a wide range.

Scratches will no longer occur.

(¥Example) Nominal dimensions (web height x flange width) e00X20
Figures 15 (a) to (d) and Table 1 show the results of selecting a representative H-beam steel of No. 0 and actually hot rolling the carbon steel to check for the occurrence of scratches on the inner surface of the flange. This will be explained using Table 2. The material used was ordinary carbon steel of 0.20$C, and the material temperature immediately before the main rolling mill, which adopted the skew roll system, was as shown in Fig. 15(a), where the web 2 was subjected to the a-roll rolling.
The temperature was about 800°C at the flange 1, and about 850°C at the flange 1.

The cross-sectional shapes of the rolls used are shown in Figures 15(c) and (d) and Table 1. Figure 15(c) is after the improvement (referred to as the new method) and Figure 15(d) is before the improvement. (referred to as the old method).As can be seen from these, the only difference regarding the roll is the shape of the portion 10 in the figure, which is the presence or absence of a taper. In addition, the definition of the dimensions of the material before and after rolling is shown in Figure 15 (a).
, shown in (b). The part 2' in the figure (a) is rolled down with a roll, and the inner surface 1' of the flange l is rolled down as shown in the figure (c).
, (d) The web is widened by pressing and spreading it with the roll side 10.

Regarding the four dimensions shown in Table 2, which show the material dimensions before and after rolling by the new method and the old method, there is almost no difference between the two.
However, there was a clear difference in the occurrence of scratches on the flange surface, and the old method produced scratches caused by the scratches caused by the rolls. The form of the flaw is similar to the results of the plasticine model experiment shown in FIG. 11(a), but the degree of flaw is milder in carbon steel. However, these flaws remain even after the subsequent finish rolling, impairing the commercial value of the product. In contrast, it was confirmed that products rolled using the new method were rolled and had good surface quality.

Table 1 (See Figures 1 and 13) Table 2 Note) See Figure 13 Note) Dimension measurements are cold measured values (effects of the invention) As explained above, the roll of the present invention By using this, scratches on the flange can be prevented and products of good quality can be obtained. In addition, even under the old method, it was found that scratches could be prevented by actively lubricating the rolls with rolling oil, for example, but in this case, gaps between the rolls and the material were likely to occur, and finishing mills were This impairs stable continuous rolling during the rolling process and causes variations in the dimensions of the shape. For both these reasons and from an economic point of view, it is clear that operating under the new method is a much better option.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are explanatory diagrams of the oblique roll method rolling method, FIGS. 1(c) and 1(d) are cross-sectional views of the rolls used in this method, and FIG. 1(d) is the roll of the present invention. Cross-sectional view. FIGS. 2(a) and 2(b) are diagrams showing an example of a conventional rolling equipment row for rolling a section having seven flange, and roll hole shapes corresponding to each rolling mill from rough rolling to shingle rolling. Figures 3(a) and 3(b) show typical examples of conventional H-beam rolling single rows, rough (BD), intermediate (RU-E) and finishing (RU-E).
FU) is a diagram showing the shape of each material cross section rolled by each rolling mill and the definition of terminology. FIG. 4 is a functional explanatory diagram of a universal rolling mill based on the relationship between the rolling rolls and the material to be rolled in the universal rolling method for rolling H-section steel, and FIG. 5 will be explained as an application example of the present invention. A diagram showing cross-sectional changes and definitions of terms in a product series with a constant inner web width. FIG. 6(a) is a plan view and a detailed explanatory diagram of each mill function based on an embodiment of the slanted roll type rolling mill according to the present invention, FIG. 6(b) is a product diagram, and FIG. 7(a) , (b) is a diagram showing an example of a finishing unipersam mill with horizontal roll body width "f" transformation. Figures 8 (a) and (b) are diagrams showing the state of contact between the oblique roll and the material during roll bite. 9 Figures (a) and (b) are plan views showing the relative positions of the roll and material during roll bite. Figures 10 (a) and (b) show the cross-sectional shape of the roll before and after the improvement. Figures 11 (a), (b), and (c) are conceptual diagrams for explaining the occurrence of scratches on rolls before and after improvement. Figures 12 (a) to (d) are suitable roll profiles. Diagram showing the procedure for making a decision. Figure 13: Contour map of the surface perpendicular to the roll axis created based on an automatic three-dimensional measuring machine for Hakamichi material (
A basic example for determining roll shape). Figure 14 is a contour diagram for a plane straight to the roll axis obtained from the anti-grip material when rolled using a roll with a shape determined based on the contour diagram in Figure 13; Figure 15 (a) -(d) are diagrams of cross-sectional shapes of materials and rolls for explaining examples.

Claims (1)

[Claims] In a shape rolling process consisting of a rough rolling process, an intermediate rolling process, and a finish rolling process, in any one or more passes between the intermediate rolling process and the finish rolling process, the axis thereof is in a plane perpendicular to the rolling direction. In contrast, a roll having a predetermined angle θ_H and a tapered surface at an angle γ with respect to a plane perpendicular to the axis is arranged so that the surface maintains contact with the inner surface of the flange of the material while the material passes through. A method for rolling a section having flanges, characterized by expanding the web of material in the width direction.