JP2512240B2 - Rough rolling method for Z-shaped steel sheet pile - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling a Z-shaped steel sheet pile manufactured from a slab by continuous casting.

[0002]

2. Description of the Related Art Conventionally, in a Z-shaped steel sheet pile rolling manufacturing method, a steel ingot heated in a soaking furnace or the like is bloomed for about 10 passes by a slab mill 11 in a rolling mill train shown in FIG. Using the shaped rectangular steel slab 21 (see FIG. 3) having a rectangular cross-section, rolled by the roll dies 23 to 32 (FIGS. 3B to 3K), the final roll dies 33 (FIG. )) By Z
The shaped steel sheet pile 34 is obtained. The dotted line in FIG. 3 (A) shows the die 23 before rolling. The shaped square steel piece 21 is subjected to rolling for several passes to reduce the gap between the upper and lower rolls in the hole die 23 shown by a dotted line in FIG. In this rolling, since the rolled material is bitten between the upper and lower mold cavities due to the rolling reduction, if the rolling in the thickness direction is performed for 2 to 3 passes, it is necessary to rotate the rolled material by 90 degrees to perform the edging pass.

After this edging rolling, the rolled material is 270
Rotate once to return to the posture before edging rolling, and perform rolling again. In this way, in the hole die 23, rolling in the thickness direction and edging rolling are repeated, and a predetermined shape is obtained by a total of 10 to 20 passes. Then, rolling is performed by the hole die 24 shown in FIG. 3 (C). In the hole die 24, a predetermined shape is usually formed by 3 to 5 passes.
With this hole die 24, a rough shaped steel piece 25 for a Z-shaped steel sheet pile is obtained. The rough shaped steel piece 25 is the final cross-sectional shape in the slab mill 11, and the rough shaped steel piece 25 requires care of the steel ingot and the flaws generated during the slab rolling, and then shown in FIG. It is reheated in the heating furnace 12 and sent to the shaped steel rolling mill group. The section rolling mill group includes a rough rolling mill 13, an intermediate rolling mill 14, and a finish rolling mill 15. The Z-shaped steel sheet pile 34 is formed by passing the rolled material through each of the roll die 26 to 33 by the rolling mill group.

As described above, there are cases where a steel ingot having a rectangular cross section is used as a material, and where continuous casting H-shaped slab is used as a material.
As shown in FIG. 4, the rolling method using this H-shaped slab as a raw material is as follows. First, as shown in FIG. 4, an H-shaped slab 41 in which a pair of parallelly arranged flanges 42 are integrally connected by a web 22 is a slab mill. 1
1 has a hole shape 50, 50a (see FIG. 5), a cavity 40, 40a is formed between the hole 43 and the web 43, and a flange 42 is formed.
Simultaneously with thin-wall rolling of only the tip portion, both flanges 42 are expanded to form a rolled material 52 in which a curved surface 51 is formed on the outside of the flange 42.

After that, as shown in FIG.
Is turned around, and the protruding portion 53 on the outer side surface of the flange 42 is reduced by lightly reducing the upper and lower flat rolls 54, 54a to flatten the curved surface 51, and the width of the flange 42 is extended. The leading end of is increased by ΔB. (Japanese Patent Publication No. 59-19765)

[0006]

However, among the rolling methods for the Z-shaped steel sheet pile 34 as described above, there are various rolling methods for obtaining the rough shaped steel slab 25 from the ingot by slab rolling as follows. There's a problem. (B) Modeling pass during slabbing, the shaping pass of the square billet 21, the edging pass, and the rotating work of the billet are heavy, and the rolling efficiency is low. (B) During the slabbing, since the rolling from the shaped rectangular steel slab 21 is large and the degree of deformation is large, the material is likely to be twisted and bent during rolling, and misrolls are also generated. (C) During slabbing, since the degree of deformation is large, many defects occur, and it is necessary to care for rough steel billets. (D) It is necessary to reheat before rolling by the shaped steel rolling mill groups 13, 14, and 15. (E) The yield from the steel ingot is low in relation to the above problems.

The present invention has been made in view of the above circumstances. The rolling efficiency and the ingot yield are improved, and there is no need to care for the slab and reheating of the rough slab is unnecessary.
An object of the present invention is to provide a rough rolling method for shaped steel sheet piles.

[0008]

A rough rolling method for a Z-shaped steel sheet pile according to the present invention uses a continuously cast H-shaped slab as a raw material,
The inside of one end of one flange of the H-shaped slab is steeply inclined, the inside of one end of the other flange is gently inclined, and the inside of the other end of the one flange is Since the inside of the other end of the other flange has a gentle inclination, the inside of the tip of the other side is steeply inclined, and is characterized in that the hole is filled under pressure with widening.
One side of one of the flanges of the shaped slab is pressed so that pressure is applied from the inside of its tip in the width direction, and the inside of the other flange is pressed so as to increase the thickness of the inside of its tip. Further, the other side of one flange is pressed down so as to increase the thickness inside the tip portion, and the other side of the other flange is pressed down so as to be pressed in the width direction from the inside of the tip portion. Therefore, on the surface sides of the web facing each other, metal flows in the width directions opposite to each other are generated, and the deformation into the asymmetric steel piece 44 close to the Z shape smoothly progresses.

[0009]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. The rough rolling method of the rough-shaped billet for Z-shaped steel sheet piles which concerns on this invention uses the H-shaped billet continuously cast as shown in FIG. In FIG. 1, 41 is an H-shaped slab, 42 and 43 are flanges of the H-shaped slab, and 44 is a web, and the pair of flanges 42 and 43 are connected to form an H-shape. Numerals 1 and 1a are hole-types turned into upper and lower rolls, respectively.

The hole shape 1 has a steep inclination with respect to the inside of the one end 43a of the flange 43 of the H-shaped cast piece 41,
Similarly, the H-shaped slab 41 has grooves 2 and 3 of a shape that is gently inclined with respect to the inner side of the one end portion 42a of the other flange 42. Further, the hole shape 1a is gently inclined with respect to the inner side of the other side tip portion 43b of one flange 43 of the H-shaped cast piece 41, and the other side tip portion 42b of the other flange 42 of the H-shaped cast piece 41 is also inside. Groove 2 with a steep slope
a and 3a.

With such a hole die 1, 1a, one end 43a of one flange 43 of the H-shaped cast piece 41 is pressed down from the inside so as to be pressed in the width direction, and one side of the other flange 42 is pressed. The tip portion 42a is pressed down so as to increase the thickness thereof. In addition, the other side tip portion 43b of one flange 43
Is pressed so as to increase the thickness inside thereof, and the other end portion 42b of the other flange 42 is pressed so as to be pressed in the width direction from the inside thereof.

Therefore, on the surface sides of the web 44 which face each other, metal flows which are directed in the width directions opposite to each other are generated, and the forming rolling is performed to fill the cavities with the progress of reduction (FIG. 1 (B)). ). As a result, the deformation of the asymmetric steel piece 45 close to the Z shape smoothly progresses, and defects such as lap flaws and biting do not occur.

The asymmetric steel strip 4 obtained as described above
5 is rolled by the next die 5, 5a to obtain a steel slab 46 as shown in FIG.
As shown in (D), a steel piece 47 having a product shape close to that of the product is obtained. Here, the rough rolling is completed, and thereafter, the Z-shaped steel sheet pile is obtained from the intermediate rolling mill through the finishing rolling mill in the same manner as in the conventional method.

[0014]

According to the present invention, the turning of the thin rolled or rolled material of the flange tip portion of the H-shaped cast piece in the rolling initial, preformed becomes unnecessary such edging rolling, less number of passes of rolling, also Z Deformation progresses smoothly, and the cycle time from the maintenance of the billet in the middle of rolling to the end of rolling can be shortened, so reheating is not necessary and rolling efficiency and steel ingot yield are improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a rolling method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an arrangement of rolling mills.

FIG. 3 is an explanatory diagram showing a hole die and a steel slab by a conventional rolling method.

FIG. 4 is an end view showing an H-shaped slab as a rolling material.

FIG. 5 is a cross-sectional view showing a state of rough rolling of a conventional H-shaped slab.

FIG. 6 is a cross-sectional view showing a conventional flange width-rolling rolling by light reduction.

[Explanation of symbols]

 1, 1a Hole type 2, 3, 2a, 3a Hole type groove 35, 35a Gap between H type cast piece and hole type 41 H type cast piece 42, 43 Flange 42a, 43a, 42b, 43b H type cast piece Tip part 44 Web 45 H type slab web

Claims (1)

(57) [Claims] 1. A continuously cast H-shaped slab is used as a raw material, and the inside of one end of one flange of the H-shaped slab is steeply inclined and the inside of one end of the other flange is gently inclined. In addition, the inside of the tip of the other side of the one flange has a gentle inclination, and the inside of the tip of the other side of the other flange has a steep inclination, so that the hole type is filled under pressure with widening. A rough rolling method for a Z-shaped steel sheet pile, which is characterized by forming.