JP4284918B2 - Method of manufacturing base material for drawing - Google Patents

Description

【００１９】
Ｎｏ．１〜４の発明例では、製品（引き抜き加工製品１４）の上下表面、左右表面ともに滑らかな表面肌をしており、更に、図４に示した目標寸法に対して寸法精度の良い製品が得られた。また、４ロール圧延機により母材を製造するにあたっても１回の圧延により製造が可能であった。
これに対して、Ｎｏ．５の比較例では、母材の縦寸法が製品の縦寸法に対して大き過ぎるため、１回の引き抜き加工では目標の製品形状に仕上げられなかった。
【００２０】
また、Ｎｏ．６の比較例では、縦横寸法減少率差が大きすぎる、すなわち、横寸法の寸法減少率が、縦寸法の寸法減少率に対して小さすぎるため、製品の左右表面に表面荒れが認められた。
さらに、Ｎｏ．７の比較例では、母材の縦寸法が製品の縦寸法に対して小さ過ぎるため、製品の寸法精度が著しく劣っていた。また、上下表面に表面荒れが認められた。
【００２１】
また、Ｎｏ．８の比較例では、母材の横寸法が製品の横寸法に対して大き過ぎるため、１回の引き抜き加工では目標の製品形状に仕上げられなかった。
【００２２】
【発明の効果】
以上説明したように、本発明の請求項１記載の引き抜き加工用母材の製造方法によると、１回の引き抜き加工により異形断面の鋼材を製造する際の母材の製造方法であって、前記鋼材の縦寸法に対する前記母材の縦寸法の比率、および、前記鋼材の横寸法に対する前記母材の横寸法の比率の両者が、それぞれ１０２％〜１２０％とするとともに、前記母材に対する前記鋼材の縦寸法の寸法減少率と、前記母材に対する前記鋼材の横寸法の寸法減少率との差を６％以内であるため、引き抜き加工を複数回行ったり、引き抜き加工パス間で熱処理を行ったりすることがないので、引き抜き加工を高能率、且つ低コストで実施できる。また、高い寸法精度、高品質での引き抜き加工鋼材を製造できる。
【００２３】
さらに、本発明の請求項２記載の引き抜き加工用母材の製造方法によると、４ロール圧延機を用いて母材の圧延を行うため、縦横寸法を同時に高精度に調整した母村の製造が可能となり、引き抜き加工鋼材の縦寸法に対する母材の縦寸法の比率、および、引き抜き加工鋼材の横寸法に対する母材の横寸法の比率の両者を１０２％〜１２０％にすることが可能となり、高能率、高い寸法精度、高品質の引き抜き加工が低コストで行える母材の製造が可能となる。
【図面の簡単な説明】
【図１】本発明に係る引き抜き加工用母材の圧延方法を示す図である。
【図２】引き抜き加工用母材を４ロール圧延機により製造する方法を概略的に示した図である。
【図３】引き抜き加工用母材の断面形状及び寸法を示す図である。
【図４】引き抜き加工後の鋼材の断面形状及び寸法を示す図である。
【符号の説明】
２ ４ロール圧延機
４，６ 水平ロール
８，１０ 垂直ロール
１２ 被圧延材（母材）
１４ 引き抜き加工鋼材（引き抜き加工製品）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a base material when manufacturing a wire / bar with a deformed cross section.
[0002]
[Problems to be solved by the invention]
In general, a steel material having a complicated cross-sectional shape is manufactured by drawing. In this drawing process, a base material having a round or square cross section is drawn into a deformed cross-section steel material. If there is a large difference between the cross-sectional shape of the base material and the cross-sectional shape after the drawing process, 2-4. A number of times of drawing is performed, and heat treatment for softening the steel is performed between passes of the drawing.
[0003]
On the other hand, many rolling methods using a two-roll rolling mill are used for the production of wire rods and steel bars used as a base material for drawing. In the rolling method using this two-roll mill, the size and shape of the surface that is not constrained by the roll cannot be controlled with high accuracy, and there is a limit to the dimensional accuracy of the rolled material.
In addition, when rolling using a two-roll rolling mill, a hole having a predetermined size and shape is processed in the circumferential direction of the roll, and rolled with a roll having a hole shape close to the shape after drawing. It is possible to reduce the number of drawing processes and omit the heat treatment by manufacturing the base material by reducing the processing rate during the drawing process. However, when carrying out small lot production, it is necessary to prepare a roll having a dedicated hole shape for each base material, and the roll cost is greatly increased. On the contrary, even when large-lot production is performed, roll wear occurs early and the shape of the hole shape is likely to change. Therefore, it is necessary to frequently change rolls, which tends to increase manufacturing costs.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and even when a drawing process into a deformed cross section (complex cross-sectional shape) is performed, a drawing base material capable of suppressing manufacturing costs and equipment costs, and It aims at providing the manufacturing method.
[0005]
[Means for Solving the Problems]
The present inventors can control the size every 90 ° in the circumferential direction of the cross section of the base material in rolling by a 4-roll rolling mill, and rolling by a 4-roll rolling mill as compared with a rolling method by a 2-roll rolling mill. It was noted that the method can control the cross-sectional dimensions of the entire circumference of the base material more finely.
[0006]
[Means for Solving the Problems]
The present invention has been completed on the basis of the above knowledge, and the method for producing a base material for drawing according to claim 1 of the present invention is a method for producing a steel material having an irregular cross-section by a single drawing process. It is a manufacturing method of a base material, Comprising: Both the ratio of the vertical dimension of the said base material with respect to the vertical dimension of the said steel material, and the ratio of the horizontal dimension of the said base material with respect to the horizontal dimension of the said steel material are 102%-120%, respectively. to together, the size reduction rate of the vertical dimension of the steel relative to the base material, as within 6% of the difference between the size reduction rate of the lateral dimension of the steel relative to the base material, be produced by rolling the base material and It is characterized by.
[0007]
Moreover, the manufacturing method of the base material for drawing of Claim 2 of this invention is a manufacturing method of the base material at the time of manufacturing the steel material of an irregular cross section by one drawing, Comprising: With respect to the vertical dimension of the said steel material Both the ratio of the vertical dimension of the base material and the ratio of the horizontal dimension of the base material to the horizontal dimension of the steel material are 102% to 120%, respectively, and the dimension of the vertical dimension of the steel material to the base material The difference between the reduction rate and the dimensional reduction rate of the transverse dimension of the steel material relative to the base material is within 6%, and the base material is rolled and manufactured by a four-roll rolling mill.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a drawing base material and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
FIG. 1 shows a four-roll rolling mill 2 suitable for manufacturing a base material for drawing according to the present invention. The four-roll rolling mill 2 includes a pair of horizontal rolls 4 and 6 and a pair of vertical rolls. Rolls 8 and 10 are provided. The horizontal rolls 4 and 6 and the vertical rolls 8 and 10 are 90 ° different from each other in the rolling direction.
[0009]
And in this embodiment, as shown in FIG. 2, the to-be-rolled material 12 which has progressed toward the 4-roll rolling mill 2 is rolled into a quadrangular cross section such as a steel bar in the rolling process by the 4-roll rolling mill 2. The base material for drawing is manufactured by this rolling.
Here, with respect to the longitudinal dimension target value A1 and the lateral dimension target value B1 of the deformed cross-section steel material after the drawing, the base material, that is, the longitudinal dimension A0 and the lateral dimension B0 after rolling by a four-roll rolling mill are as follows. It is set so as to satisfy the expressions (1) and (2).
[0010]
1.02 × A1 ≦ A0 ≦ 1.20 × A1 (1)
1.02 × B1 ≦ B0 ≦ 1.20 × B1 (2)
Furthermore, the difference S between the dimension reduction rate of the vertical dimension of the modified cross-section steel material relative to the base material defined by the following formula (3) and the dimension reduction rate of the horizontal dimension of the irregular cross-section steel material relative to the base material is 6% or less. The vertical dimension A0 and the horizontal dimension B0 are set so that
[0011]
S = | [(A0−A1) / A0− (B0−B1) / B0] × 100 | (3)
In a 4-roll rolling mill, rolling is performed while simultaneously restraining the longitudinal direction and the transverse direction of the cross section of the material to be rolled during rolling, so that rolling that satisfies both the above formulas (1) and (2) is accurate. Can be implemented well.
Here, the lower limit values of the vertical dimension A0 and the horizontal dimension B0 of the base material are set to 1.02 times the vertical dimension target value A1 and the horizontal dimension target value B1 of the modified cross-section steel material, respectively. In such a case, not only the processing by the drawing process becomes insufficient, the surface surface of the steel material after processing does not become smooth, but also the metal flow sufficiently occurs at the corner of the steel material after the drawing process. In addition, it does not exhibit a square cross section.
[0012]
In addition, the upper limit values of the vertical dimension A0 and the horizontal dimension B0 of the base material are 1.20 times the vertical dimension target value A1 and the horizontal dimension target value B1 of the modified cross-section steel material, respectively. It becomes difficult to produce a drawn steel material by a single drawing process, the number of drawing processes increases, and a heat treatment needs to be performed between the drawing passes.
[0013]
Further, if the difference S between the vertical dimension reduction ratio and the horizontal dimension reduction ratio defined by the above equation (3) exceeds 6%, the surface with the smaller dimension reduction ratio (vertical or horizontal) is sufficient. The problem of shape defect and rough surface occurs.
An example of the shape and dimensions of the base material 12 and the steel material 14 after drawing will be described with specific numerical values. The base material 12 shown in FIG. 3 has a longitudinal dimension of 33.0 mm and a lateral dimension of 37.5 mm. It has a rectangular cross section. FIG. 4 shows the shape and dimensions of the steel material 14 after the drawing process. The steel material 14 has a quadrangular cross section, the vertical target dimension maximum value is 30.0 mm, the vertical target dimension minimum value is 28.2 mm, The average value of the dimensions is 29.1 mm, the horizontal target dimension is 34.5 mm, and the upper surface has a curved surface shape with a curvature radius of 83 mm.
[0014]
Therefore, the vertical dimension (33.0 mm) of the base material 12 is 1.134 times the average vertical dimension value of the steel material 14 after the drawing process (hereinafter referred to as the drawn product 14), and the maximum vertical dimension value (30.0 mm). ) And 1.173 times the minimum vertical dimension of the drawn product 14, and the lateral dimension (37.5 mm) of the base material 12 is the lateral dimension (34. It is 1.100 times that of 5 mm). Further, the vertical dimension reduction rate of the drawn product 14 relative to the base material 12 is a minimum of 8.0% and a maximum of 14.6%. Further, the dimensional reduction rate of the lateral dimension of the drawn product 14 with respect to the base material 12 is 9.1%. Therefore, the difference between the vertical dimension reduction ratio and the horizontal dimension reduction ratio is 1.1% at the minimum and 5.5% at the maximum. In the cross-sectional shape and size of the base material 12 and the cross-sectional shape and size of the drawn product 14 described above, the above formulas (1) and (2) are satisfied, and the length of the deformed cross-section steel material relative to the base material is vertical. Since the difference S between the dimension reduction rate of the dimension and the dimension reduction rate of the transverse dimension of the deformed cross-section steel with respect to the base material is 6% or less, the drawn product 14 has a smooth surface on both the upper and lower surfaces and the left and right surfaces. In addition, the metal flow sufficiently occurs in the corner portion and becomes highly accurate with respect to the target shape.
[0015]
In the present embodiment, the shape of the drawn product 14 has a substantially rectangular cross section with the curved upper surface. However, the gist of the present invention is not limited to this, and the cross section has a trapezoidal shape, for example. The same effect can be achieved even with a polygonal drawn steel material or a polygonal drawn steel material with grooves.
[0016]
【Example】
In producing the drawn material having the cross-sectional shape and cross-sectional dimensions shown in FIG. 4, the base material was produced by rolling to a vertical dimension and a horizontal dimension shown in Table 1 using a 4-roll rolling mill. Table 1 shows the percentage of the base material dimension after drawing (product dimension): the value of base material dimension / product dimension × 100, and the dimension reduction rate due to drawing: (base material dimension−product dimension) / The value of base material size × 100 is also shown for each of the vertical and horizontal dimensions.
[0017]
In addition, the vertical / horizontal dimension reduction rate difference is also shown. Regarding the vertical dimension, the maximum value of the vertical dimension after drawing is 30 mm, and the minimum value is 28.2 mm. Therefore, the value of the base material dimension / product dimension xl00 and the dimension reduction rate are the maximum value. The minimum value was shown.
[0018]
[Table 1]

[0019]
No. In the invention examples 1 to 4, the upper and lower surfaces and the left and right surfaces of the product (drawn product 14) have smooth surface skins, and a product with good dimensional accuracy with respect to the target dimension shown in FIG. 4 is obtained. It was. Further, when the base material was manufactured with a four-roll rolling mill, it could be manufactured by one rolling.
In contrast, no. In Comparative Example 5, the vertical dimension of the base material was too large with respect to the vertical dimension of the product, so that the target product shape could not be finished by one drawing process.
[0020]
No. In Comparative Example 6, the vertical and horizontal dimension reduction rate difference was too large, that is, the horizontal dimension reduction rate was too small with respect to the vertical dimension reduction rate, and surface roughness was observed on the left and right surfaces of the product.
Furthermore, no. In Comparative Example 7, the dimensional accuracy of the product was extremely inferior because the vertical dimension of the base material was too small relative to the vertical dimension of the product. Moreover, surface roughness was recognized on the upper and lower surfaces.
[0021]
No. In Comparative Example 8, the horizontal dimension of the base material was too large with respect to the horizontal dimension of the product, so that the target product shape could not be finished by one drawing process.
[0022]
【The invention's effect】
As described above, according to the manufacturing method of the drawing process for the base material according to the first aspect of the present invention, there is provided a method for producing a base material in the production of steel of modified cross-section by drawing in one, the Both the ratio of the vertical dimension of the base material to the vertical dimension of the steel material and the ratio of the horizontal dimension of the base material to the horizontal dimension of the steel material are 102% to 120%, respectively, and the steel material to the base material a size reduction rate vertical dimension of, for the is within 6% difference between the size reduction rate of the lateral dimension of the steel for the base material, and go and go several times drawing, a heat treatment between drawing path Therefore, the drawing process can be performed with high efficiency and at a low cost. Moreover, it is possible to manufacture a drawn steel material with high dimensional accuracy and high quality.
[0023]
Furthermore, according to the method for manufacturing a base material for drawing according to claim 2 of the present invention, since the base material is rolled using a four-roll rolling mill , the manufacturing of the base village in which the vertical and horizontal dimensions are simultaneously adjusted with high accuracy can be performed. The ratio of the vertical dimension of the base material to the vertical dimension of the drawn steel material and the ratio of the horizontal dimension of the base material to the horizontal dimension of the drawn steel material can both be 102% to 120%. It is possible to manufacture a base material that can perform drawing with high efficiency, high dimensional accuracy, and high quality at low cost.
[Brief description of the drawings]
FIG. 1 is a view showing a rolling method of a base material for drawing according to the present invention.
FIG. 2 is a view schematically showing a method of manufacturing a base material for drawing using a four-roll rolling mill.
FIG. 3 is a diagram showing a cross-sectional shape and dimensions of a drawing base material.
FIG. 4 is a diagram showing a cross-sectional shape and dimensions of a steel material after drawing.
[Explanation of symbols]
2 4 Rolling mills 4, 6 Horizontal rolls 8, 10 Vertical rolls 12 Rolled material (base material)
14 Drawing steel (drawing products)

Claims (2)

A manufacturing method of a base material when manufacturing a steel material having an irregular cross-section by a single drawing process,
The ratio of the longitudinal dimension of the base material with respect to the longitudinal dimension of the steel, and, both the ratio of the transverse dimension of the base material with respect to the lateral dimensions of the steel product, as well as 102% to 120%, respectively,
A size reduction ratio of the longitudinal dimension of the steel relative to the base material, as within 6% of the difference between the size reduction rate of the lateral dimension of the steel relative to the base material, characterized in that produced by rolling the base material A method of manufacturing a base material for drawing. A manufacturing method of a base material when manufacturing a steel material having an irregular cross-section by a single drawing process,
Both the ratio of the vertical dimension of the base material to the vertical dimension of the steel material, and the ratio of the horizontal dimension of the base material to the horizontal dimension of the steel material are 102% to 120%, respectively.
Manufactured by rolling the base material with a 4-roll rolling mill with a difference between the vertical dimension reduction rate of the steel material relative to the base material and the horizontal dimension reduction rate of the steel material relative to the base material within 6%. A method for producing a base material for drawing, characterized in that:

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