JPS5823501A - Rolling method for bar steel - Google Patents

Abstract

PURPOSE:To reduce the original unit of rolls advantageously by considerable decrease in the use of costly caliber rolls by using flat roll passes frequently in reducing of blooms or billets to bar steel, and rolling the bar steel with the caliber roll passes disposed partly. CONSTITUTION:A blank material 8 having a square section is rolled continuously >=2 times with flat rolls 9, 9', 9''. The rolled material 8 is subjected to a process for trimming the sectional shape of the material 8 by a single pass of box type rolls 10 or combined passes of diamond caliber rolls 11 and square caliber rolls 12 repeatedly each time when needed, whereby the section thereof is reduced. In this way, the twists and overturns produced when the material is subjected to continuous passes of 2 times or over with flat rolls are corrected with the caliber roll passes, so that the continuation of the succeeding rolling is made easy. The life of the caliber rolls is remarkably prolonged by the said method and the rolling efficiency for the bar steel is improved considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling long steel.The manufacturing of long steel, that is, square steel and round steel, involves berth rolling performed multiple times using one rolling mill I' as shown in FIG. Or, as shown in Figure 1, a continuous rolling mill, ν, J''
. . . or by combining the methods shown in FIGS. 1 and 2 and performing semi-continuous rolling.

Conventionally, the rolling mills used for these rolling processes include J and J in Figure 1.
As exemplified in It, j, 4 and 7, the hole shape was turned, and the cross section of the passing material was shaped by this hole and the cross section was reduced.

Therefore, the hole shape of each pass is determined by the cross-sectional shape and dimensions of the material before rolling in that pass and the desired cross-sectional shape and dimensions of the material after rolling, so in the case of multi-pass rolling,
Conventional full-hole rolling requires the use of many different types of grooves, and therefore has the following problems:
(2) When grinding and reusing worn rolls,
In the case of hole crushing, uneven wear is large, so the amount of rolling from the start of use until the roll becomes unusable is small, and the amount of cutting is also large, so the number of reuses is small, i.e., the life of the roll is shortened. Since it is short, the shipping cost is high.

(5) Due to the body length of the roll, several companies are limited to 111 holes in turning for one roll, and if many types of holes are required, KFi has a large number of rolls), and the cost is high. I・ (4)! It is necessary to manufacture a ninth gauge to check whether the shape of the hole turned on the roll is the specified shape. (1) IE rolling machine roll with the specified hole. If the rolls are not set, it is necessary to stop the rolling operation and replace the rolls.

(6) In the case of a groove type ■-roll, alignment of opposing groove types of one roll set in the rolling mill and alignment of the ninth guide device and the groove type to correctly guide the rolled material to the groove type. Because it is necessary to be strict.

Long rolling stop time (7) As mentioned in (2) above, when the amount of rolling by one roll or its groove is small, the s& of roll change or groove change becomes high and the rolling stop time is due to this. This invention has developed a particularly advantageous method of rolling long steel by making extensive use of rounding and flat roll passes, and partly arranging double-hole roll passes to eliminate the above-mentioned problems.This invention has the following development results. In other words, the number of passes when rolling round steel and square steel is usually 10 or more passes, but the number of passes for shaping into a predetermined product shape is 2 to 4, and the remaining passes are exclusively rolled. Although the main purpose is to reduce the cross section of the material to be rolled, this invention focuses on the fact that it is not necessary to adjust the shape with the holes 11. In order to solve the above-mentioned problems of J10-KLh rolling, we provide a rolling method for square steel and round steel that makes extensive use of flat roll passes and partially includes perforated rolls. The details of the present invention will be explained with reference to the drawings.
The basic structure of the present invention is as shown in Figure 1, in which a rectangular cross-section pile is continuously flat-rolled more than lt times.
After rolling with a good rolling process, the cross-sectional shape of the material to be rolled can be changed by a single pass of the box-hole type roll IO or a combination of the diamond-hole type U-roll and the square-hole type roll/J. In the flat roll pass, the restraining force of the material by the rolls is small and the material is less stable than in the grooved roll pass, so the process shown in Figure 1 is Like 7?Troll/J.

The material rolled at /J' is twisted as shown by the arrow / reference in the figure, and also collapses as shown by /I in Figure 4, and these tendencies increase synergistically as the number of passes increases. Therefore, in this invention, after performing one or more continuous passes with a flat roll, the twisting and falling are corrected with a groove pass, and the rolling is impossible. This makes it easier to continue rolling.However, there is no advantage to using rolls for each flat roll pass.However, excessive continuous rolling during the flat roll pass may cause damage to the corners of the rolled material. Part 14
As shown in Figure 7, center sharp and aperture, box hole fi.
l/7. /7' or diamond hole M/I /I
When rolling with #, a part of the corner is pressed down and the product is rolled. Therefore, using a general box hole type and diamond hole type, we conducted a trial test on the shape of a part of the corner of the material and the occurrence of denting on an actual rolling mill. As shown in the results, if the roundness radius, that is, the radius of the corner part 14 of the material before rolling, is equal to or larger than the short side dimension, the occurrence of dents will be extremely reduced. If the width of the flat surface of the material becomes narrower than JJ of the short side dimension, the width of the flat surface of the material will become narrower, and subsequent rolling will become unstable. ．． -One!
11 Bo is appropriate.

In addition, when using a box hole type, 4&=-
When using a square hole type or diamond hole type to obtain a predetermined rounded part in a part, first give a rounded part to the corner part using a diamond hole mold, then pass the finished product through the square hole mold with an O0 turn. Coco? Give IIK are.

If the corner radius of the material is already small, such as the bloom on the continuous casting side, start with a grooved roll pass, and then apply 2 at or 1 continuous flat roll pass according to Jin's invention. All you have to do is repeat the combination with the hole-shaped roll pass more than once. By using an a-ru pass), you can also have the effect of training a part of the corner of the material.

★In the case of large square steel products, the box hole type pass of this invention can be finished using the square hole type pass as the final stage, but in the case of round copper products, the forming pass is performed following the hole type cool pass of the present invention. Figure 10 shows an example using a semi-continuous mill. ◎210 In order to manufacture a round steel product from a bloom with a square cross section, At the first rough mill l de /70 tyh hanging angle cross section 1 at the first rough mill J0 at tzgmm cross section, and finishing continuous mill J/,
JJ, Jj, JJ1. JJ, roll to a 0 mm diameter cross section.

Figure 1 shows the cross-sectional shape and roll shape of the material for each pulse. The first rough ζ rule/f is reverse rolling with one pass, and the first pass is rolled on the flat roll surface/F'. The next 1st pass is rolled with a box hole die to adjust the cross-sectional shape and round the corners.
Although the rit Ruco 0 has an lHm ascending angle cross section with an l pass, all are 7 rat p-ru passes. Next, finishing step 1 (Le Jl
The diamond hole W■-Luco/' and the finishing of the square hole m roll of the second mill n are JJ"t'/21, and the subsequent finishing is full J-wM4!! Ru JJ.

JIE, Ko! , J4 oval hole type roll JJ', J
j' hole l1c1-le J411, JJ1
A product of 20 cross sections was continuously rolled in 9 forming passes by alternating with fKII
In the cross section of XI6111ull, the radius of a part of the corner was approximately lawn and the short side dimension of the material was O#7-. A part of the corner radius of the material with the /jOs+s angle cross section before being rolled in the diamond ridge hole IIJl of the first round is approximately /
1%, it was about 1011 of the short side dimension of the material, but when moving from the diamond hole IIJl# to the square hole 1IJJ', the material should be turned f00. There is no indentation during rolling of any of the holes, and a product with no surface flaws can be rolled.

As described above, in this invention, rolling with a flat roll is carried out in one continuous pass or in multiple passes with ζ. By rolling with a caliber sail placed between flat roll passes to correct the cross section to a normal rectangle, and continuing stable 7-rat rolling, the above-mentioned drawbacks of the conventional method can be advantageously solved. However, there is a limit to the continuation of a flat roll pass, that is, a reference line for transitioning to a grooved roll pass, and in actual operation, there is a limit to the continuation of the flat roll pass, which is the reference line for transitioning to a grooved roll pass.

(2) The value of the radius of a part of the corner of the material to be rolled should be set to the back side, and the pass stage that exceeds the allowable range should be selected. A general allowable limit is 3 mm as a percentage of the length of the short side of the rolled material, and it is desirable to determine the pass schedule so that both such limits are maintained throughout the entire rolling process.Thus, according to the present invention, By drastically reducing the number of expensive hole rolls used, it is possible to advantageously reduce the per-unit consumption of rolls and significantly improve the rolling efficiency due to electric stretching with a remarkable roll life.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams showing a conventional example of a rolling mill arrangement for square steel and round steel, Figure 3 is an explanatory diagram of the hole shape, and Figure 3 is an example of the rolling process according to the present invention. Figures 1 and 4 are explanatory diagrams showing the twisting and falling conditions associated with operation in a flat roll bath. Figure IIIE7 and TST diagram show the effect of excessive passes by flat rolls on product quality. Explanatory diagram, Figure 2 is a graph showing the relationship of partial corner radius on the surface flaw occurrence rate of IIi products. It is a sectional view showing trends. Patent Applicant: Kawasaki Steel Co., Ltd. Fig. 1 Fig. 2 Fig. 8 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9
#! Rinsashi 41! Side dimensions are shown in Figure 1θ Figure 11

Claims (1)

[Scope of Claims] 1. Area reduction processing from plume or billet to square steel, round steel, and long bar steel by continuous arc rolling machine Tangjiusha semi-continuous rolling mill is mainly performed by flat cooling, except for the product OIl shape stage. For one pass or more consecutive flat cool passes,
A method for rolling a long steel, which includes a step of correcting the irregular cross-sectional shape of the material to be rolled, which is accumulated by a flat roll pass in order to combine I~copass holes [0-ru pass. 2. The method according to claim s1, in which the hole-shaped roll pass is a box caliber h/babasu - The method of claim s1, in which the hole-type roll pass is one pass with a diamond yoi river and a square caliper. . 4. The hole 111a path is located in the =- part of the material to be rolled,
The claimed scope of the invention is to round off the radius of the J-Jj length of the a side. 3* or the method of writing the number.