JPH04288903A - Method for rough rolling z shaped steel sheet pile - Google Patents

Abstract

PURPOSE:To roll the rough steel billet for Z shaped steel sheet pile. CONSTITUTION:The H shaped cast billet 41 of the continuous casting is used as a stock, the forming is executed by filling the calibar with reduction being followed with the width expansion with the cabilars 1, 1a that the inner side of one side top end part 42b of one hand flange 42 of this H shaped cast billet 41 is made to the shary slope, the inner side of one hand top end part 43b of the other flange 43 is made to the gentle slope, and the inner side of other side top end part 42a of the above one hand flange 42 is made to the gentle slope, and the inner side of other side top end part 43a of the other hand flange 43 made to the shary slope. The turn of the rolled stock is becomed needless, the number of rolling passes and the protrusion of lateral direction are reduced, the re-heating and the repair are becomed needless, so tha rolling efficiency and the yield of steel billet are improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of rolling Z-shaped steel sheet piles manufactured from continuous cast slabs.

0002

[Prior Art] Conventionally, in the rolling manufacturing method of Z-shaped steel sheet piles, a steel ingot heated in a soaking furnace or the like is subjected to about 10 passes of blooming in a blooming mill 11 of a rolling mill row shown in FIG. The shaped square steel piece 21 (see FIG. 3) with a rectangular cross section is rolled by each roll hole mold 23 to 32 (FIG. 3(B) to (K)), and the final roll hole mold 33 (FIG. 3(L)) is rolled. )) by Z
A shaped steel sheet pile 34 is obtained. The dotted line in FIG. 3(A) indicates the groove 23 before rolling. The shaped square steel piece 21 is rolled to a predetermined thickness by repeating rolling several times in a groove 23 shown by dotted lines in FIG. In this rolling, an overhang occurs between the upper and lower holes due to the reduction of the rolled material, so if two or three passes of reduction in the thickness direction are performed, it is necessary to rotate the rolled material by 90 degrees and perform an edging pass.

After this edging rolling, the rolled material is
Rotate once to return to the position before edging rolling, and then roll again. In this manner, rolling in the thickness direction and edging rolling are repeated in the groove 23, and a predetermined shape is obtained by a total of 10 to 20 passes. Next, rolling is carried out using the groove 24 shown in FIG.
With this hole mold 24, a rough-shaped steel piece 25 for Z-shaped steel sheet piles is obtained. The rough-shaped steel billet 25 has a final cross-sectional shape in the blooming mill 11, and this rough-shaped steel billet 25 requires cleaning of the steel ingot and defects generated during blooming, and is then processed as shown in FIG. It is reheated in a heating furnace 12 and sent to a group of shape steel rolling mills. The section steel rolling mill group includes a rough rolling mill 13, an intermediate rolling mill 14, and a finishing mill 15. A Z-shaped steel sheet pile 34 is formed by passing the rolled material through each of the roll holes 26 to 33 using the rolling mill group.

As mentioned above, there are cases where the material is a steel ingot with a rectangular cross section, and cases where the material is a continuously cast H-shaped slab. In the rolling method using this H-shaped slab as a raw material, as shown in FIG. 1
Hole shapes 50, 50a (see FIG. 5) of No. 1 form cavities 40, 40a between the web 43 and the flange 42.
At the same time, both flanges 42 are expanded to form a rolled material 52 with a curved surface 51 formed on the outside of the flanges 42 while performing thin-wall rolling only on the tip end.

Thereafter, as shown in FIG. 6, this rolled material 52
, the protruding portion 53 on the outer surface of the flange 42 is reduced in area by light rolling with the upper and lower flat rolls 54 and 54a, the curved surface 51 is flattened, and the width of the flange 42 is widened. This increases the tip of ΔB by ΔB. (Special Publication No. 59-19765)

[
0006

[Problems to be Solved by the Invention] However, among the methods for rolling the Z-shaped steel sheet piles 34 as described above, there are various rolling methods for obtaining the rough-shaped steel slabs 25 from the steel ingot by blooming rolling. There's a problem. (a) During blooming rolling, the shaping pass, edging pass, and rotating work of the shaped square steel billet 21 have a large load, and the rolling efficiency is low. (b) During blooming rolling, the rolling reduction from the shaped square steel piece 21 is large and the degree of deformation is also large, so that the material is likely to be twisted or bent during rolling, and misrolls may also occur. (c) During blooming rolling, the degree of deformation is large, so many flaws occur, and the rough shaped steel pieces need to be maintained. (d) It is necessary to heat the steel again before rolling it in the section steel rolling mill groups 13, 14, and 15. (e) In relation to the above problems, the yield from steel ingots is low.

The present invention has been made in view of the above circumstances, and it improves rolling efficiency and steel ingot yield, and also eliminates the need for maintenance of steel slabs and reheating of rough shaped steel slabs.
The purpose of the present invention is to provide a method for rough rolling sheet piles.

[0008]

[Means and operations for solving the problem] The rough rolling method for Z-shaped steel sheet piles according to the present invention uses continuously cast H-shaped slabs as raw materials,
The inside tip of one side of one flange of this H-shaped slab forms a steep slope, the inside tip of one side of the other flange forms a gentle slope, and the inside tip of the other side of the one flange forms a steep slope. H
One side of one flange of the cast piece is rolled down so that pressure is applied in the width direction from the inside of its tip, and the inside of the other flange is rolled down so that the thickness increases inside the tip. Further, the other side of one flange is rolled down so as to increase the thickness inside its tip, and the other side of the other flange is rolled down so that pressure is applied from the inside of its tip in the width direction. Therefore, metal flows in opposite width directions occur on the mutually opposing surfaces of the web, and deformation into an asymmetrical steel piece 44 close to a Z shape progresses smoothly.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail with reference to the accompanying drawings. The method of rough rolling a rough-shaped steel slab for Z-shaped steel sheet piles according to the present invention uses an H-shaped slab continuously cast as a raw material, 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.
The pair of flanges 42 and 43 are connected to form an H shape. 1 and 1a are hole shapes cut into the upper and lower rolls, respectively.

[0010] The hole shape 1 is steeply inclined toward the inside of one end portion 43a of one flange 43 of the H-shaped slab 41;
Similarly, the H-shaped slab 41 has grooves 2 and 3 that are gently sloped toward the inside of the tip 42a on one side of the other flange 42. Further, the hole shape 1a forms a gentle slope with respect to the inner side of the other side tip 43b of one flange 43 of the H-shaped slab 41, and is also formed on the inside of the other side tip 42b of the other flange 42 of the H-shaped slab 41. The groove 2a has a shape that is steeply sloped against the groove 2a.
, 3a.

Due to such holes 1 and 1a, one side tip 43a of one flange 43 of the H-shaped slab 41 is pressed down from the inside in the width direction, and one side of the other flange 42 is pressed down from inside. The tip portion 42a is rolled down so that the thickness increases on the inside thereof. Also, the other side tip portion 43b of one flange 43
is rolled down so as to increase its thickness on the inside thereof, and the other side tip 42b of the other flange 42 is rolled down so that pressure is applied from the inside in the width direction.

[0012] Therefore, metal flows in opposite width directions are generated on the mutually opposing surfaces of the web 44, and forming rolling is performed to fill the holes as the rolling progresses (Fig. 1(B)). ). As a result, the deformation into the asymmetrical steel piece 45 close to the Z shape progresses smoothly, and defects such as lap flaws and protrusion do not occur.

Asymmetrical steel piece 4 obtained as described above
5 is rolled in the next groove 5, 5a to obtain a steel billet 46 as shown in FIG.
), a steel piece 47 having a shape closer to that of a finished product is obtained. Here, the rough rolling is completed, and after that, Z-shaped steel sheet piles are obtained by passing from an intermediate rolling mill to a finishing rolling mill in the same manner as in the conventional method.

[0014]

[Effects of the Invention] According to the present invention, preforming such as thinning rolling of the flange end of the H-shaped slab, turning of the rolled material, and edging rolling at the initial stage of rolling is unnecessary, and the number of rolling passes is reduced. The deformation into the Z-shape progresses smoothly, and the cycle time until the end of care rolling of the steel billet during rolling can be shortened, so reheating is not necessary, and rolling efficiency and steel ingot yield are improved.

[Brief explanation of the drawing]

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 the arrangement of rolling mills.

FIG. 3 is an explanatory diagram showing a hole shape and a steel billet formed by a conventional rolling method.

FIG. 4 is an end view showing an H-shaped slab to be rolled.

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

FIG. 6 is a sectional view showing a state of flange extension rolling by conventional light reduction.

[Explanation of symbols]

1, 1a Hole mold 2, 3, 2a, 3a Groove portions 35, 35a of the hole mold Gap between the H-shaped slab and the hole mold 41 H
Shaped slabs 42, 43 Flanges 42a, 43a, 42b, 43b Tip portion 44 of H-shaped slab Web 45 Web of H-shaped slab

Claims (1)

[Claims] [Claim 1] A continuously cast H-shaped slab is used as a material, and this H-shaped slab is used as a raw material.
The inside tip of one side of one flange of the shaped slab forms a steep slope, the inside tip of one side of the other flange forms a gentle slope, and the inside tip of the other side of the one flange forms a gentle slope. A method for rough rolling a Z-shaped steel sheet pile, characterized in that the inside of the other end of the other flange forms a steeply sloped hole, and the hole is filled by rolling with width expansion.