JPS5921404A - Rolling method of wire rod - Google Patents

Abstract

PURPOSE:To prevent the rolling trouble occuring in the looping between stands in a block mill which has a specified gear ratio for each of stands and rolls a wire rod under application of specified tension by disposing alternately flat rolls and round rolls to said mill. CONSTITUTION:Flat rolls and round caliber rolls are alternately disposed and a wire rod is rolled with such rolls in a finishing mill for wire rods which is disposed alternately with the rolls of the respective stands with each 45 deg. deviation to eliminate the need for twisting the steel material, has a specified gear ratio for each of the respective stands on account of mechanical construction, drives each stand with a single driving motor and rolls the steel material under application of slight tension. The ratio (drawing ratio) between the sectional area of the steel material in the inlet of each stand and the sectional area of the steel material in the outlet is maintained at <=13.0 and the forward slip at <=6%. The rolling is thus made possible even if the rolling mill has no caliber rolls specific to product sizes for each of the respective stands.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of rolling a wire rod by alternately arranging L round force ripper rolls.

Shingetsu's finishing rolling mill generally has a high rolling speed (6
0 m/+) and to ensure quality (less surface flaws, good force and dimensional accuracy), each stand roll is placed alternately at 45 degrees to avoid the need for twisting of the copper phase (75 = 75). The block mill has a gear ratio of 1,000,000, and rolls by intentionally applying a small amount of tension.However, the rolling method of each stand of the block mill has conventionally provided width expansion restraint to ensure high elongation and prevent surface defects. ; The production is carried out by the hole rolling method of an oval-round method in which oval caliber rolls and round caliber rolls, which have excellent shapeability during hot processing, are alternately arranged 1".

However, in this block mill groove rolling method, (1) Finishing Because a groove roll (material: WC) specific to the product size is used for each nutand, the number of expensive carbide rolls on hand is large due to roll management, resulting in high costs. It takes.

(2) Rolls must be rearranged every time a product is manufactured, resulting in a significant loss of time during the rolling process.

There is a drawback marked i.

As a result of extensive research to eliminate the drawbacks of conventional methods, the present inventors have
In a block mill that has a fixed gear ratio for each nutand and performs HE rolling by applying a fixed speed, the conventional
By using flat rolls instead of Palcalibur rolls and arranging bar rolls alternately, rolling troubles caused by loops between stands can be prevented, and the quality is equivalent to or higher than that of the conventional method (surface flaws and It has been found that dimensional accuracy can be ensured. As a result, rolling can be performed on an OJ basis without having to have a caliber roll specific to each product size for each nutand as in the conventional method, and the number of rolling noises of expensive carbide rolls can be significantly reduced in terms of roll management. It has been found that changeover time can be reduced to approximately the same amount.

The purpose of the present invention is to provide a method for rolling wire rods in a block mill that can ensure quality equal to or higher than conventional groove rolling, reduce the number of expensive carbide rolls on hand, and shorten the roll change time. This is what we provide. That is, the present invention is a linear phase rolling force method characterized in that flat rolls and round caliber rolls are alternately arranged in a block mill for rolling.

Next, we will explain in detail the following.

The roll arrangement specified in the present invention is generally an interlaced arrangement of maple calibers and round calibers in block mills. By simply using a roll entrance roller guide with the same structure as when rolling, it is possible to prevent the copper a) from falling during finish rolling.
Moreover, it is possible to easily ensure the biting property of steel materials, and furthermore, since the final roll is round, it is very convenient to ensure the dimensional accuracy of the product.

Next, an embodiment of the present invention will be described with reference to FIG.

Figure 1 is a graph with the drawing ratio of Steel I taken on the horizontal axis and the advance ratio taken on the vertical axis. , i: gear speed increasing ratio, V: actual measured value.

In the figure, ★ indicates the occurrence of rolling trouble in the block mill (
5,5φ, 5 Q m/s), ■ indicates the occurrence of a WC roll breakage accident during rolling trouble in a block mill, the roll arrangement is flat roll → round carino 9-〇-roll, ・ is round carino The roll arrangement from f-roll to flat roll is shown.

Flat rolls and round carino rolls are arranged alternately to make the inlet steel material size 17.5φ and the inlet rolling temperature 900℃.
, maximum speed 60m/! When rolling a size 5.5φ with I, as shown in Figure 1, the stretch ratio of the inlet cross-sectional area to the outlet cross-sectional area is 1.3 or less, and the advance rate is 6 inches or less.
By designing the rolls, it is possible to avoid rolling troubles due to loops between stands and troubles such as breakage of rolls.0 1st person U compared the rolling conditions of the present invention and the conventional method. It is something. As shown in Table 1, in a block mill that uses a UFF machine with a gear ratio of 1'Jjl for each nutand and a tension of 2 to 7q6, as shown in Fig. 1, the gear ratio is 1.35 or more and When the advance rate exceeds 7, rolling troubles occur due to loops between bolts, and when this luzo is excessive, unreasonable pushing force is applied and roll splitting accidents may occur.

In the present invention, since the copper phase inlet shape of a general block mill is circular, it is preferable to alternately distribute flat rolls and round calibers. Figure 2 shows the product size 55φ, (1, soil speed 60 m This is a comparison of the rolling inertia during rolling by /s.Here is a circular cross section of the wire rod with a copper phase shape of 17.5φ at the entrance of the block mill.

When comparing the present invention (indicated by the solid line) with the conventional method (indicated by the dashed-dotted line) such that J<J (in Fig. 2), the reduction in area of the flat roll is smaller and the area reduction rate of the round caliber roll is larger;
On average, it is equivalent to the conventional method.

It can also be seen that the advancement rate is proportional to the area reduction rate.

The biting angle θ in FIG. 2 represents the angle shown in FIG. 3, and in the case of the present invention, it is slightly larger than the conventional method, but the biting property may be approximately the same.

Table 2 Comparison of product quality between the conventional method and the product according to the present invention is Table 2. As shown in Table 2, it can be seen that the present invention can ensure the same quality as the conventional method. Rolling according to the present invention was carried out to a cumulative total of over 8,000 tons (rolling tons), but there were no troubles during rolling.

Table 3 ffi 3 & N block mill 1st of 10 stands
Incorporate the flat roll into the stand and the third nutand with A.
This is a comparison table showing the effects of the present invention and the conventional method when rolling the entire rise of the product, and it can be seen that this contributes to a significant reduction in the interest burden due to roll holding and to a reduction in cost. A comparison of the block mill roll changeover time shows that the present invention can shorten the time by about 30% compared to the conventional method.

As described above, the present invention is based on the flat L1 roll and the round caliber roll being arranged alternately in the professional and kumil.
Since it is a straight rolling method that rolls with a Myoshin ratio of 1.3 or less and a rolling ratio of 6% or less, it eliminates the need for a flat stand and greatly reduces the number of groove rolls on hand compared to the conventional groove rolling method. It is possible to reduce the number of rolls and reduce the value of conuts, and since there is no need to change rolls in a flat stand, it is possible to shorten the time for changing rolls, and the same or better effect can be achieved in terms of quality.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between the drawing ratio and advance rate according to the present invention, Fig. 2 is a comparison diagram of FE drawing characteristic values between the present invention and the conventional method, and Fig. 3 is a diagram showing the biting angle θ. It is. Figure 1, Figure 3, 25-

Claims (2)

[Claims] (1) Each stand roll is arranged alternately by 45 degrees so that twisting of Ml is not necessary, and the mechanical structure has a constant gear ratio for each shoe stand, and is driven by a single drive motor, with a slight tension. 1. A method for forming a wire line, which is characterized in that flat rolls and round caliber rolls are arranged alternately and pressure IJ-rolling is carried out in the line finishing IJ- and rolling process in which two H-rolls are carried out. (2) The entrance to each stand miI old cross section base and exit []
2. The method for rolling a wire rod according to claim 1, wherein the wire rod is rolled at a draw ratio of 1.30 or less, which is a ratio of the cross-sectional area of the steel material, and at a progress rate of 6% or less.