JPH0399703A - Rolling method for u-shaped steel pile - Google Patents

Abstract

PURPOSE:To evade the effective barrel length shortage constraint of a rolling roll by performing the enlarging rolling in order of the specified web width per one caliber forging with the caliber forgings in the specified number up to the final finishing caliber forging, while making the center line length between the caliber forgings at the same value. CONSTITUTION:A U-shaped steel pile is rolled from a rectangular sectional billet 1 by a 2-high roll rolling mill. In that case a web 2 is made in the shape bent in a wavy form till immediately before the caliber forging K-1 of the final finishing C from the rough forging (a) caliber K-9. A claw part is bent by the final finishing caliber forging K-1 to form the web 2 in a straight line shape. Now, the web width in 20mm maximum per caliber forging is rolled with its enlarging in order by 1-4 caliber forgings of until the final finishing caliber forging K-1, while making the center line length l of the web 2 in each caliber forging K-9-K-1 at the same value. The caliber forging width can thus be reduced in a U-shape steel sheet pile rolling.

Description

[Detailed description of the invention] (Industrial field of application) The present invention relates to a method for rolling U-shaped steel sheet piles,
Specifically, the present invention relates to a rolling method for rolling U-shaped steel sheet piles, which avoids the restriction of insufficient effective length of rolling rolls by making the hole width smaller than in conventional methods.

(Prior art) As shown in Fig. 6, the rolling method for U-shaped steel sheet piles is to roll the web 2 from a rectangular slab 1 with 8 to 10 holes with a slight inclination, or to roll the web 2 in a straight line. It is known that rolling is carried out in a shape. The hole width W of the pass in shape rolling by a double roll rolling mill is basically approximately larger than the width of the steel material of the front hole, and the same can be said of the web width B in this case. However, when bending is involved, the hole width W in the case of -1 (bending of the claw portion 12) is -2>K-1 (Japanese Patent Laid-Open No. 54-1284 ft7).
(see issue). In this way, as the rolling progresses, the web width B becomes
Although it is slight, it is increasing, but this trend is the 6th.
Rough modeling (a), intermediate modeling (b), and finishing modeling (
In the order of C), the amount of increase decreases, especially after -4,
During the final finishing step 11, the amount is close to that of the original, or conversely, the next hole shape becomes smaller. Figure 8 shows an example.
FIG. 8(A) shows the steel material after G5, and FIG. 8(B) shows the hole shape of G-4. Fig. 8 (c) ni-5 and ni-4 are superimposed on each other with respect to the center CL of the hole.
The corner portions 7 and 8 of the web of l) are shown in the rolled state. Whether the webs 1liiB are the same and the difference in web width B is zero, the inner side of the web at the hatched portion 18 is stretched by the difference in the thickness of the corner part.

The hole width W is expressed as the web width B plus twice the distance f from the flange to the claw part, but these are the web 2, flange 11, and claw part 12 of the product shown in FIG. , full width W. It is naturally determined by the relationship between the dimensions and shape, the web width B of the front and rear holes, and the distance tall f from the flange to the claw, and the hole width W cannot be changed freely.

(Problems to be Solved by the Invention) These conventional techniques do not pose any manufacturing problems, especially if the equipment specifications are compatible with the product. but,
Among these, the total width of the product W. If the number of roll stands or the effective length of the rolling roll shown in FIG. 10 is insufficient, production becomes impossible. FIG. 10 shows an example in which, in the case of tandem rolling, a -5 hole type (dotted line) is arranged on the roll. When rolling steel sections with a double roll rolling mill, the upper and lower rolls (21, 22) move left and right during rolling! l
Thrust collars 23, which serve as stoppers, are arranged at both ends of the roll so that the thickness deviation of the left and right flanges 11 and claw portions 12 does not exceed a certain level by moving the roll (for example, in the directions of arrows Y+ and Y2). is the basis. In this case, some percentage of the rolling reaction force (usually 3
Since the thrust collar acts in the horizontal direction (said to be approximately 100%), the thrust collar is
The thickness of the thrust collar is required, but if the length of the roll body is insufficient, the thrust collar thickness becomes small as shown in a, and rolling becomes impossible.

In order to avoid this, in order to reduce the web width B, if the web width B is expanded near the final finishing roll,
The more the front hole type is used, the smaller the web width becomes, or the following problems occur. If the expansion of the web width B between the grooves by rolling is increased, (1) the length of the web plate will be elongated, and the web thickness will become partially thinner, making it impossible to obtain a uniform thickness. ■
At the same time, flange 1 of -1 is added to the final finishing hole mold in Figure 6.
1, and the influence of the stretching spreads to the claws 01 to 12, resulting in under-stretching of the claws as shown at 19 in FIG. 9, or imbalance between the left and right claws at 1920.

■Wear of the web corner part 17 progresses quickly and the surface quality is poor. etc., the product quality will deteriorate and the problem will not be solved.

(Means for Solving the Problems) The present invention has been made in view of the problems of the prior art, and it is possible to roll and shape a rectangular cross-section steel piece using a double roll rolling mill. In a rolling method in which the web is bent into a wavy shape immediately before the final finishing hole, and the claws are bent and formed into a straight shape in the final finishing hole, the web is formed between each hole. Rolling of U-shaped steel sheet piles, which is characterized by sequentially expanding the web width to a maximum of 20 mm per hole in 1 to 4 holes up to the final finishing hole while keeping the center line length approximately the same. It's a method.

for) The present invention will be explained in detail below.

FIG. 1 shows an example of a mill arrangement for implementing the present invention. In the figure, 3.4 is a rough mill, 3 is a reversible D mill, 4 is a subsequent rough mill, 5 is an intermediate mill, 6 is a finishing mill, and 4 to 6
One-hole, one-pass tandem rolling is performed. Note that the dotted mill indicates an unused mill.

FIG. 2 is an explanatory diagram of the order of rolling of a U-shaped steel sheet pile according to the present invention, in which a rectangular section steel piece No. 1 is used, a forming hole mold is used in which the web is bent in a wave shape, and a rough forming ( a) Noni-9
-8 (BD mill 3), K-7 (second stage rough mill 4), -5 (intermediate mill 5) for intermediate modeling (b), -4 for finishing modeling (C) (production) -1 (finishing mill 6) to produce a product.The hole width W of the finishing hole type Tol is determined from the dimensions and shape of the web 2, flange 11, and claw portion 12 of the product shown in Fig. 7. It is determined by the web width B and the distance f from the flange to the claw part.Among these, the distance f of each hole type before 12 is determined approximately by the mutual relationship between the hole types. K
Bend the hole-shaped web 2 before K-2 into a wave shape: If the plate length fl of the web (hereinafter referred to as the web center line length) is increased and the web width B is made smaller accordingly, then before K-2 It is possible to make the hole width W smaller. For example,
What is the relationship between the web width B in the grooves from to -5? The degree of curvature of the web waveform is increased so that each groove has approximately the same value, and there is no stretching effect on the web centerline length between the grooves.
The hole width B can be made smaller than the conventional one. Naturally, the cumulative amount of this small hole width W is 15>K-4>K-3.
> to -2, so the number of holes that sequentially reduce the web width can be selected depending on how much the web width is desired to be reduced.

FIG. 3 shows the relationship between the web width B and the web centerline length using K-4 and -3 as examples.
Figure 3 (A) shows the hole shape of Ni-4, Figure 3 (B) shows the hole shape of Ni-3, and Figure 3 (C) shows the hole shape of K-4 and Ni-3. It shows the rolled state of corner portions 7 and 8 of the webs in FIGS. In the relationship between -4 and G3, the web width B is -3>K
-4, and the curvature of the web waveform, that is, the height h of the waveform, is set to -3</
If the relationship is set to −4, the state of the corner part of the web after rolling (as shown in
Although the width is expanded, in reality, the larger waveform bending degree of -4 compared to -3 is bent and stretched to the web shape of -3 during the rolling process, and the width is actually increased by the linear length of the web. The hole shape of the previous pass (here -4
) can be reduced by ΔB. However, there is a limit to the reduction amount ΔB of the web width B.

Figure 4 shows the state at the start of biting between the hole molds.
4 and -3 are shown in the example, and 910 is the upper roll and lower roll of -3, respectively.

FIG. 4(a) shows a case where the web width increase ΔB in Ni-3 is relatively large, and the lower roll 10 supports the flange 11 made of K-4 steel with its surface, but the upper roll 9 It is in an unstable state where it is in contact with the upper part 12 at point e.

In this state, the biting point of the upper roll's claw is in contact at one point,
Moreover, when the gap i between the flange portion 11 and the upper roll becomes large, a shift of 130 mm from the center of the toe 4 steel material is likely to occur, and the thickness of the claw portion 12 becomes unbalanced on the left and right sides.
This may result in a product with unbalanced claws as shown in Figure 19.20.

Strategy 4 (b) shows the case where ΔB is close to zero, and the lower roll 10 is supported by surface contact of the flange 11 at point g of the web 2, and the upper roll 9 is supported from the claw part 12 to the flange 1.
1 The lower part is in contact with the large surface, and the K-4 steel material is K-4 steel.
-30-L, it is in a very stable and ideal biting state with no left and right deviations possible. In general, normal rolling is carried out in the range shown in FIG. 4(B) or in a range between FIGS. 4(B) and 4(A). The possible range of this ΔB is Max20 as confirmed by model experiment.
It is possible to go up to 15 mm, but considering stability
The following are desirable. In addition, the reduction of the total web width B by -5 with respect to T1 (expansion margin in rolling)
If it becomes too large, the degree of curvature of the web waveform will increase and local roll wear on the convex parts may occur.
It is desirable that the thickness be less than mm.

In addition, some webs have a wave-shaped bent shape in groove rolling using a 2m roll rolling mill (Japanese Patent Laid-Open Publication No. 128467/1989, etc.), but this is due to the U This is within the scope of the conventional technology for forming steel sheet piles and is fundamentally different from the present invention.

Figure 5 shows an example of an insert logite for preventing the steel material from shifting laterally with respect to the roll when the expansion margin ΔB during rolling becomes large. In order to reduce the space between the flange 11 and the guide, guide rollers 15 and 16 are installed to prevent the steel material from shifting from side to side. Combination use is recommended.

(Example) Next, the present invention was applied to rolling of a steel sheet pile 100 mm wider than the conventional steel sheet pile using the mill arrangement shown in FIG.
The results of an example carried out by the method shown in FIGS. 3 and 3 will be explained.

The cross-sectional dimensions of the rectangular steel are 520 mm wide x 160 mm high, compared to 470 mm wide x 180 mm high for conventional steel sheet piles.
The web width increment between the grooves from -9 to -5 is based on the conventional technology ΔB, and from K-4 onwards to -1, the grooves with ΔB as shown in Table 1 are used. did. As a result, as shown by the dotted line in FIG. 10, with the hole mold of the prior art, the strength of the thrust collar 23 could not be ensured, but the thrust collar thickness was as thick as u2=λ++25 mm, and no defects occurred due to rolling. The strength was ensured. In addition, in consideration of rolling stability, a severe kite as shown in FIG. 5 was used in combination, and as a result, a good product comparable to conventional products was obtained.

Table 1 (Effects of the invention) According to the present invention, when trying to secure the number of molding holes for the steel sheet pile product to be manufactured, it is possible to arrange a plurality of holes in 10-holes or 10-holes. In the case of arranging one mold per roll, a remarkable effect can be obtained in that it is possible to effectively avoid a situation where the roll body length is insufficient and production becomes impossible.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a rolling line implementing the present invention;
FIG. 2 is an explanatory diagram of the order of rolling U-shaped steel according to the present invention,
Fig. 3 is an enlarged explanatory view of Fig. 2, (A) Hani-4, F port) Hani-3 hole type, (8) shows an example of their superposition, and Fig. 4 ( stomach). (B) is an explanatory diagram of the state at the start of biting between the grooves in Fig. 3, Fig. 5 is an explanatory diagram of the artificial guide for more stable rolling in the present invention, and Fig. 6 is an explanatory diagram of the conventional state. Diagram showing the order of U-shaped steel sheet pile rolling, Figure 7 is the product diagram, Figure 8
Figures ((), (Ill) (8) are enlarged explanatory views of Figure 6, Figure 9 is an explanatory diagram of product defects when trying to avoid the drawbacks of the conventional method, and Figure 10 is the effective length of the roll. 1 is a diagram illustrating the necessity of a thrust collar and its strength. 1... Rectangular cross-section steel plate 2... Web 3...
BD mill 4...Late rough mill 5...Intermediate mill 6...Finishing mill 7.8...Corner part of web 910...K-3 upper roll 11...Flange 12... Claw part 1314・
... Entrance guide 1516 ... Guide roller 17 ... Corner wear 18 ... Stretching of the inside of the web 1920 ... Unbalance of the claw 2122 ... K-5 upper and lower rolls 23 ... Thrust Color a... Rough forming b... Intermediate forming C... Finish forming B... Hole web width f... Width from flange to claw W... Hole width ℃... Center line length of the web h...Height of the web waveform ΔB...Amount of web width expansion between the holes e...Contact point between the upper roll and the steel material g...Contact point between the lower roll and the steel material i... ...Gap between the upper roll and the preparation flange L...Effective length of the roll A, u2...Thickness of the thrust collar 7-6th

Claims (1)

[Claims] 1. When rolling and shaping a rectangular cross-section steel piece using a double roll rolling mill, the web is bent into a wavy shape from the rough forming hole mold to just before the final finishing hole mold, and the claw part is bent and formed in the final finishing hole mold. At the same time, in the rolling method of forming the web into a straight line, the length of the center line of the web between each groove is approximately the same, and the length of the web from 1 to 4 up to the final finishing groove is
A method for rolling U-shaped steel sheet piles, which is characterized by sequentially expanding the web width to a maximum of 20 mm per hole in several holes.