JP3521122B2 - Method of manufacturing H-section steel - 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 producing an H-section steel from a rolled material by combining rolling processing using two rolls and bending forming processing.

[0002]

2. Description of the Related Art As shown in FIG. 10, for example, an H-section steel production line comprises a breakdown mill BD (double rolling mill), a rough universal mill UR, an edger mill E, and a finishing universal mill UF in order from the upstream side. Using a breakdown mill BD, the roll gap is adjusted in multiple passes while rolling into a rough shaped steel piece having a web portion and a flange portion, and the rough shaped steel piece is rolled in the rough universal mill UR and the edger mill E. The H-section steel is normally manufactured by one-pass finish rolling in the finish universal mill UF after intermediate finishing rolling in a plurality of passes while adjusting the above.

Each of the universal mills (UR, UF) has a total of four rolling rolls, namely, upper and lower horizontal rolls and left and right vertical rolls in the rolling direction, and the web portion of the material to be rolled is flanged to the upper and lower horizontal rolls. The part is rolled to a predetermined thickness in multiple passes while adjusting the gap between the rolls by the side faces of the left and right vertical rolls and the upper and lower horizontal rolls.

[0004]

However, in this method, the roll wear on the side surfaces of the upper and lower horizontal rolls is severe,
After rolling, scratches and rough skin occur on the inner surface of the flange of the rolled material. (Fig. 13) In particular, in the case of materials such as stainless steel and titanium, which are difficult to machine, that have large seizure with the roll during rolling, the inner surface of the flange is severely scratched and roughened, and it is necessary to remove scratches after rolling. is there.

The cause of the scratches and rough skin is that the roll peripheral speed at which the side surface of the horizontal roll comes into contact with the corner portion of the inner surface of the flange of the material to be rolled and the edge portion of the inner surface of the flange portion greatly differ from each other. This is because the roll moving direction of the roll part that rolls down the inner surface of the part is greatly different.

That is, to explain in detail with reference to the cross-sectional view of the state of rolling by the universal mill shown in FIG. 11, when the material is rolled correctly, the inlet speed of the material to be rolled and the outlet speed of the rolled material are generally roll circumferences. Each is determined by the speed and the amount of reduction in the cross section. The average value V _m of the material velocity at the inlet and the outlet is generally considered to be practically no problem even when viewed as the average value of the material velocity in the roll bite.

As shown in FIG. 11, the universal mill has a horizontal roll composed of an upper roll 15 contacting the upper inner surface of the material to be rolled and a lower roll 16 contacting the lower inner surface of the material to be rolled; Rolling is performed by a total of four vertical rolls including a right roll 17 abutting on the right side flange portion of the rolled material and a left roll 18 abutting on the left side flange portion of the rolled material. So, for example,
Assuming that the average value V _m is equal to the roll peripheral velocity at the roll radius Rm (distance from the roll axis R to the imaginary point G) passing through the virtual point G in FIG. 11, the corner portion of the inner surface of the flange portion is assumed. The roll peripheral speed R1 (distance between the roll axis R and the web portion) is R1 / Rm times, which is faster than the average value (average speed) V _m . On the contrary, the roll peripheral speed R2 (distance between the roll axis R and the inner surface edge portion of the flange portion) at the flange inner surface edge portion becomes R2 / Rm times slower than the average value (average speed) V _m . This means that even if the position of the roll radius Rm changes, a large difference occurs in the roll peripheral velocity at the corner portion or the edge portion of the inner surface of the flange portion or both as compared with the average value (average velocity) Vm.

On the other hand, the rolling direction of each rolling roll is the Y1 direction of the upper roll 15, the Y2 direction of the lower roll 16, the X1 direction of the right roll 17, and the X2 direction of the left roll 18. Figure 1 shows the direction of rolling down the inner surface of the flange.
As described in 2, the roll moving direction is perpendicular to the angle θ of the flange portion with respect to the web portion, and the roll moving direction of the side surface portion of the horizontal roll that rolls down the inner surface of the flange portion is perpendicular to the roll axis. That is, a large difference of 90-θ ° occurs between the rolling direction of the inner surface of the flange portion and the roll moving direction of the roll portion that rolls down the inner surface of the flange portion. for that reason,
The difference between the rolling direction of the inner surface of the flange portion and the roll moving direction of the roll portion that rolls down the inner surface of the flange causes a large slip between the material to be rolled and the roll. Further, due to the difference between the rolling direction of the inner surface of the flange portion and the roll moving direction of the roll portion that rolls down the inner surface of the flange portion, the contact length between the material to be rolled and the roll during rolling is increased, and the material to be rolled and the roll are Promotes slipping.

That is, the greater the distance from the roll radius Rm, the greater the difference between the rolled material speed and the roll speed on the inner surface of the flange portion, and the smaller the angle θ of the flange portion with respect to the web portion, the smaller the rolling direction of the inner surface of the flange portion and the inner surface of the flange portion. There is a large difference in the roll movement direction of the roll part that rolls down the roll, and the length of contact between the material being rolled and the roll during rolling becomes long, so slippage between the material and the roll becomes large and material scratches due to roll wear occur. , Rough skin will occur.

However, in order to reduce the roughness, it is necessary to make the angle θ of the flange portion with respect to the web portion of the material to be rolled in the rough universal mill UR extremely large. However, if this angle θ is too large, the edger mill E There is a risk that the flange will buckle during edging rolling of the flange tip due to
Rolling at F is also difficult. In view of the above conventional problems, the present invention aims to provide a method for producing an H-section steel 10 that does not cause rough skin without using an expensive universal rolling line.

[0011]

SUMMARY OF THE INVENTION The present invention comprises a rolling step of rolling an intermediate rough shaped material of H-section steel by two rolls into an intermediate shaped material,
Then, in the method for producing an H-section steel by performing a forming step of forming the intermediate shape material into an H shape, the rolling roll hole die of the rolling step is such that the web portion of the intermediate rough shape material is the axis of the rolling roll. In addition to having an inclination with respect to the core, the flange portion on one side on one end side and the flange portion on one side on the other end side have an angle at right angles to the axis of the rolling roll. It is a method for manufacturing an H-section steel characterized by rolling. In addition, in the intermediate rough material, the inclination of the web portion with respect to the axis of the rolling roll is 20.
It is effective to set an angle of ° to 45 °.

The angle θ of the flange portion with respect to the web portion of the intermediate rough material and the angle ψ at which the intermediate rough material and the axis of the rolling roll are inclined are applicable in the range of 20 ° to 45 °. Is larger, the difference in peripheral speed between the intermediate rough material and the rolling roll is larger.
Further, if the angles of the respective flange portions with respect to the web portion are the same, the inclinations of the web portions can be made the same during the rolling process alternately performed, so that the shape of the roll roll die can be simplified. Further, if the θ and ψ are too small, the angle γ of the rolled down flange with respect to the roll axis is large, and the effect of preventing scratches and rough skin during rolling is reduced. Since the bending process becomes large, problems such as an increase in the number of bending processes occur in the forming process.

Then, in the rolling step, the other two sides of the intermediate roughened material are rolled by the rolling roll so that the flange portions of the two sides which are perpendicular to the axis of the rolling roll are not in contact with the hole shape of the rolling roll. After performing the rolling process by pressing down the flange portion and the web portion with a rolling roll, and then performing the rolling process by making the inclination of the web portion of the intermediate rough material into an inclination reverse to the axis of the rolling roll, The intermediate rough-formed material is rolled into an intermediate-shaped material having a desired size by rolling while alternately repeating this inclination.

Further, in the intermediate shape member, it is desirable that the sides of the flange portion make the same angle with respect to the web portion. Since the angles are the same, the distance from the roll radius Rm can be made substantially the same over all passes, and stable rolling can be performed. Further, it is desirable that the hole shape of the rolling roll is rolled so that the amount of reduction by the rolling rolls on the inner side and the outer side of the flange portion on the two sides to be rolled is even with respect to the workpiece. This can suppress the generation of a force in the direction of rotation applied to the material to be rolled during rolling, and as a result also prevent the material to be rolled out of the groove. Furthermore, it is desirable that the forming step is performed by bending the intermediate shaped material in a cold / warm temperature range. This is because sufficient lubrication is possible in the cold and warm temperature range, so the coefficient of friction between the work material and the forming roll can be lowered, and since the work material itself has a large hardness, seizure with the forming roll is reduced. Furthermore, it is possible to reduce deterioration of the surface quality due to the scale of the surface of the work material.

As described above, the rolling process in which the shaft center of the rolling roll and the web portion of the intermediate rough material are inclined at an angle ψ,
By alternately repeating the rolling process which is inclined at an angle opposite to the axis of the rolling roll, the intermediate shaped material having a predetermined size can be obtained. In the rolling to the intermediate rough material, the angle between the axial center of the rolling roll and the web portion of the intermediate rough material is set so that the distance from the rolling roll radius Rm, the rolling direction of the inner surface of the flange portion and the inner surface of the flange portion. There is an advantage that the difference in the roll movement direction of the rolling roll part that reduces Therefore, slippage between the intermediate rough material and the rolling roll is reduced, and scratches and rough skin during rolling can be prevented.
Further, the center of inclination of the axial center of the rolling roll and the web portion of the intermediate rough material is preferably the web portion center where the distance from the roll radius Rm of the flange portion and the web portion on the two sides to be rolled down is the smallest. . As a result, surface defects that are likely to occur on the flange portion can be suppressed.

Further, as a rolling material for rolling into an intermediate rough material, a plastically deformable metal such as stainless steel, heat resistant steel, structural steel, ordinary steel, aluminum, titanium, etc. may be used. it can. Especially in the case of difficult-to-machine materials such as stainless steel, heat-resistant steel, and titanium, the deformability is low,
Since the rough skin is likely to occur during rolling, the effect of the present invention is further exerted. Further, in the above H-section steel, the length of the web portion and the width of the flange portion are the same as those of the web portion length <flange portion width, web portion length> flange portion width. It can also be applied to the manufacture of H-section steel. Further, it can be applied when the thickness of the web portion and the thickness of the flange portion are the same or different.

Further, in order to prevent the rolling roll hole die and the intermediate rough material from contacting each other during rolling, the hole portion through which the flanges of the two sides pass has a sufficient width, and the inner surface of the hole portion has a roll modification. For cutting, it is desirable to have an angle α of about 2 to 8 °. (Fig. 9) This is because if the angle α is too small, the cutting allowance during roll cutting becomes large and it becomes uneconomical in operation, and if it is too large, the root of the flange part that does not contact the roll swells and the next rolling process occurs. It will cause defects. By molding this intermediate rough shape material with four side flanges in the cold and warm temperature range,
It is possible to obtain an H-shaped steel shape.

Further, the rolling process and the forming process can be carried out at any temperature of hot, warm and cold. The rolling process is preferably performed by hot rolling at 800 ° to 1250 °. As a result, it is possible to easily and quickly perform intermediate rough forming with high productivity. Further, it is preferable that the above-mentioned forming process is performed in a cold-warm process at room temperature to 600 °. As a result, the surface texture of the final shape can be improved. Furthermore, the forming process is not limited to roll forming,
It can also be performed by press molding.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for producing an H-section steel from a rolled material by combining rolling processing by two rolls and forming processing by bending, wherein the rolling material is formed into a flange portion and a web portion. H consisting of a rolling step of rolling from an intersecting portion of the flange portion to an intermediate rough material having a shape with an angle θ, and a molding step of forming the intermediate rough material into an H shape having an angle θ of 0 ° It is a method for manufacturing a shaped steel.

(Embodiment 1) A method for manufacturing an H-section steel according to an embodiment of the present invention will be described with reference to FIGS.
The H-section steel to be manufactured in this example is, as shown in FIG. 8, composed of flange portions 102 and 103 and a web portion 101, and has an H-shaped steel section having a right-angled root portion 104 with which the flange portion and the web portion abut. It is 10. Above H-section steel 1
In manufacturing 0, as shown in FIGS.
The roughing step of rolling or pressing the rolled material 1 into the X-shaped intermediate rough material 3, the rolling step of rolling from the intermediate rough material 3 to the intermediate shaped material 5, and the intermediate shaped material 5 being H
It comprises a forming step of cold forming into shape 10.

This will be described below. First, in the embodiment of the present invention, as shown in FIGS. 1 to 4, in the intermediate step, from the billet-shaped rolling material 1 using stainless steel to the first intermediate body 2, the intermediate rough shape material 3, and the second intermediate body. 4 is rolled and the X-shaped intermediate shaped material 5 is formed by hot rolling as shown in FIG. Further, the rolling from the rolling material 1 to the intermediate coarse material 3 is carried out by ordinary groove rolling without inclining the groove shape, and from the intermediate rough material 3 to the X-shaped intermediate shape material 5, the axis of the rolling roll is Rolling was performed by alternately inclining the hole shape while keeping the core horizontal. In the hot rolling process, for example, when processing the intermediate shape material, a pair of rolling rolls of an upper roll 150 and a lower roll 160 were used like the rolling rolls shown in FIG. 7.

In this embodiment, as shown in FIG.
(Flange portions 62, 63, 64 of the intermediate shape member 5,
65) = ψ (angle formed by the rolling roll and the web portion 61) = γ (angle formed by the flanges 62, 64 not having a right angle with the axis R, R'of the rolling roll) =
It was carried out at 30 ° so that the height of the web and the width of the flange in the H shape were equal. The height of the web portion here is H shown in FIG. 8, and the width of the flange portion is W shown in FIG.

Further, in order to equalize the height of the web portion and the width of the flange portion, the widths of the flange portions 62, 64 on the two sides that come into contact with the rolling roll during rolling and the flange portions 63 on the two sides that do not come into contact with the rolling roll during rolling, The width shrinkage and thickness shrinkage of 65 are derived from many experiments and reflected in the hole type design.

Next, in the forming step, the angle θ of the flange portions 62, 63, 64, 65 of the intermediate shape member 5 is set to θ.
= 0 °, that is, to change from the X shape to the H shape,
Bending with a forming roll was performed in the cold. In this embodiment, the flange portions 62, 63, 64 of the intermediate shape member 5 are
Bending was performed twice in order to change the angle θ of 65 from 30 ° to 0 °. In order to adjust the width of the flange portion between the first pass and the second pass, a reduction was applied to the edge portion of the flange portion in a direction substantially perpendicular to the web portion. As a result, the H-section steel 10 having the desired shape and dimensions and excellent surface properties can be obtained. Further, if necessary, a heat treatment may be carried out in order to adjust the internal quality of the cold-bent portion.

Next, the present invention will be described in more detail. First, in the rolling step, as described above, the intermediate shaped material 5 is rolled by a normal rolling mill having two rolls in the upper and lower sides without using the universal mill having the rolls in the four upper, lower, left and right directions at the same position. As can be obtained, as the rolling condition for the intermediate shaped material, the same angle ψ as the angle θ of the flange portion with respect to the orthogonal direction of the web portion in the intermediate shaped material was inclined. (Fig. 6)

In the rolling process for the intermediate rough-formed material, by tilting the angle ψ, the flange portions 63 and 65 on the two sides of the flange portions 62 to 65 on the four sides are perpendicular to the axis of the rolling roll. Become. The flange portions 63, 65 on the two sides perpendicular to the axis of the rolling roll do not come into contact with the rolling roll during rolling, that is, are not rolled.
In consideration of shrinking the thickness during rolling, the hole shape of the rolling roll has a sufficient width with respect to the thickness of the flange portion of the intermediate rough material. In addition, the flange portions 62, 64 on the other two sides
The angle γ with the axis of the rolling roll becomes equal to θ and ψ by inclining the hole shape of the rolling roll by an angle ψ, which is more than the angle (90 ° −θ) of the axis of the rolling roll before the inclination. The angle θ is small in the range of 20 to 45 °. By reducing the angle γ, the distance from the roll radius Rm and the difference between the rolling direction of the inner surface of the flange portion and the rolling movement direction of the rolling roll portion that rolls down the inner surface portion of the flange become smaller. The flange portions 62 and 64 on the two sides and the web portion 61 are pressed down by a rolling roll.

In the next pass, the groove shape of the rolling roll is tilted at an angle of −ψ (−2ψ for the previous pass), so that the flange portions 62 and 64 on the two sides, which have been pressed down in the previous pass, have axes of the rolling roll. It is perpendicular to the core. As with the previous pass, these two sides should not come into contact with the rolling rolls. The flange portions 63 and 65 on the other two sides form an angle γ with the axis of the rolling roll.
Is equal to −θ, −ψ, and the distance from the roll radius Rm is almost the same as the previous pass. In this previous pass, the flange portions 63 and 65 and the web portion 61 on the two sides which are not in contact with the rolls are pressed down by the rolling rolls.

[0028]

According to the present invention, the rolling step of rolling the rolling material from the intermediate rough shape material to the intermediate shape material and the forming step of forming the intermediate shape material into H-section steel are performed in this order, and In order to manufacture steel, the X-shaped intermediate shape material 5 can be formed by forming the material to be rolled into a hole shape that is inclined with respect to the axis of the rolling roll during the rolling step. At this time, the rolled portion of the material to be rolled is smaller in distance from the radius Rm of the rolling roll than in the case where the rolling material is not inclined, so that the slip generated between the material to be rolled and the rolling roll is small and the rough surface is not generated. rare. Therefore, even in the rolling process for difficult-to-process materials such as stainless steel and titanium, the occurrence of case hardening and scratches can be reduced, and as a result, the surface skin can be improved significantly.

According to the manufacturing method of the present invention,
It is possible to perform the rolling process of forming the intermediate shape material with the rolling machine consisting of the upper and lower rolls without using the universal mill, which is an expensive dedicated equipment with rolling rolls arranged on the top, bottom, left and right, and is rolled by the universal mill. The H-section steel produced according to the present invention is excellent in surface texture as compared with the above.

[Brief description of drawings]

FIG. 1 is a sectional view of a rolling material according to an embodiment of the present invention.

FIG. 2 is a sectional view of a first intermediate body according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of an intermediate rough material according to an embodiment of the present invention.

FIG. 4 is a sectional view of a second intermediate body according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of an intermediate shaped material according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of an intermediate shape material for explaining the relationship between the intermediate shape material and the axis of the rolling roll according to the embodiment of the present invention.

FIG. 7 is a perspective view illustrating a relationship between an intermediate shaped material and upper and lower rolling rolls according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view of the H-section steel after the forming process according to the example of the present invention.

FIG. 9 is a cross-sectional view illustrating the relationship between the hole shape of the rolling roll immediately after the rolling process of the intermediate shape material and the intermediate shape material according to the example of the present invention.

FIG. 10 is an explanatory diagram of a conventional H-section steel production line.

FIG. 11 is a cross-sectional view illustrating a roll peripheral speed during rolling by a conventional universal mill.

FIG. 12 is a cross-sectional view illustrating roll reduction during rolling by a conventional universal mill.

FIG. 13 is an explanatory diagram of a surface flaw state of a rolled H-section steel according to a conventional technique.

[Explanation of symbols]

1: Rolled material, 2: the first intermediate, 3: Intermediate rough material, 4: second intermediate, 5: Intermediate shape material, 10: H-shaped steel, 61: Web part, 62, 63, 64, 65: flange portion, 101: Web part, 103: flange part, 104: root part 150: upper roll, 160: lower roll

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21B 1/00-1/46 B21B 27/02

Claims (6)

(57) [Claims] 1. An H-section steel is obtained by performing a rolling step of rolling an intermediate rough-section material of H-section steel with two rolls to form an intermediate-shape material, and then a forming step of forming the intermediate-shape material into an H-shape. In the method for producing, the rolling roll hole die of the rolling step, the web portion of the intermediate rough material has an inclination with respect to the axis of the rolling roll,
A flange portion on one side on one end side and a flange portion on one side on the other end side have an angle at right angles to the axis of the rolling roll, and rolling is performed by this. Shaped steel manufacturing method. 2. The rolling step according to claim 1,
Rolling is performed by rolling down the flange portion and the web portion of the other two sides of the intermediate rough material by the rolling roll so that each flange portion that is perpendicular to the axis of the rolling roll does not contact the hole shape of the rolling roll. After that, the inclination of the web portion of the intermediate rough shape material is reversely inclined with respect to the axis of the rolling roll to perform the rolling, and the intermediate rough forming is performed by repeating the inclination alternately. A method for producing an H-section steel, wherein the material is an intermediate shape material having a desired size. 3. The intermediate rough-shaped material according to claim 1, wherein a web portion of the intermediate rough-shaped material is 20 ° with respect to an axis of a rolling roll.
A method for producing an H-section steel, characterized in that the H-section steel is rolled while having an angle of ~ 45 °. 4. The method according to claim 1, wherein
The method for producing an H-section steel, wherein the intermediate rough-formed material is rolled such that the angles formed by the respective sides of the flange portion with respect to the web portion are the same. 5. The method according to any one of claims 1 to 4,
The hole shape of the rolling roll is characterized in that the material to be processed is rolled so that the amount of reduction by the inner and outer rolling rolls of the flanges on the two sides is even.
Shaped steel manufacturing method. 6. The method according to any one of claims 1 to 5,
In the forming step, a method for manufacturing an H-section steel is characterized in that the intermediate-shape material is bent in a cold and warm temperature range to form an H-section steel.