JP2020163418A - Web center position correction rolling mill for h-section steel, and h-section steel rolling method - Google Patents

Abstract

To prevent the deterioration of web center position accuracy that is likely to occur in universal rolling and improve the productivity and product quality of rolling shaping in an H-section steel production line using universal rolling.SOLUTION: A web center position correction rolling mill that corrects the plate thickness center of the web portion of a rolled material to the width center position of a flange portion with respect to the rolled material, i.e., an intermediate material in the rolling process of H-section steel, which rolling mill includes a vertically symmetrical horizontal roll pair and a horizontally symmetrical upright roll pair. The horizontal roll pair is provided with a relief portion in the vicinity of the flange tip corresponding to a portion on a side surface of the horizontal roll pair. The upright roll pair is provided with a collar that restrains the flange tip of the rolled material.SELECTED DRAWING: Figure 6

Description

The present invention relates to an apparatus and a method for correcting the web center position of an H-beam produced by rolling. Specifically, the present invention relates to a material to be rolled immediately before finishing universal rolling immediately after intermediate rolling. The present invention relates to a web center position correction rolling mill for correcting the web center position of a material and a rolling method for H-shaped steel.

10 (a) and 10 (b) show an example of a rolling equipment 1 for manufacturing H-section steel by hot rolling on the production line L. In the example of FIG. 10A, first, the rectangular cross-section slab 11 of the material is heated to the temperature required for hot rolling in the heating furnace 3, and the material is engraved on the upper and lower roll pairs of the rough rolling mill 4. Rough rolling is performed by a rectangular row to form a material having an H-shaped rough cross section (hereinafter referred to as an H-shaped rough material 13). Subsequently, the intermediate universal rolling mill 5 is used to reduce the thickness of the web portion 10 and the flange portion 12 of the H-shaped rough material 13 with respect to the H-shaped rough material 13, and the intermediate universal rolling mill 5 is simultaneously used. The first intermediate material 14 is formed by rolling down the width of the flange portion 12 of the H-shaped rough shape member 13 and forging and shaping the end face by an adjacent edger rolling mill 9. Then, the plate thickness of the first intermediate material 14 is lightly reduced by the finishing universal rolling mill 8 to straighten the inclined left and right flange portions 12, and this is straightened perpendicular to the web portion 10. , H-shaped steel product 16 is manufactured.

As shown in FIG. 10B, a skew roll rolling mill 7 (skew roll rolling mill) is arranged between the intermediate universal rolling mill 5, the edger rolling mill 9, and the finishing universal rolling mill 8, and the skew roll rolling mill 7 is arranged. The row roll rolling mill 7 widens and shapes the in-web method (web width dimension indicated by (web height-2 x flange thickness)) of the first intermediate material 14 to a predetermined dimension (hereinafter referred to as in-web method widening rolling). In some cases, the second intermediate material 15 is formed, and rolling is applied to the second intermediate material 15 by a finishing universal rolling mill 8 to manufacture an H-shaped steel product 16.

H-section steel is a steel product with a wide variety of uses and a large number of cross-sectional sizes. Not only the plate thickness of the web part and flange part, but also the in-web method and flange piece width ((flange width-web thickness)) ) / 2 to produce products with various cross-sectional dimensions with different widths and lengths for one side of the flange. The thickness of the web and flange of the H-section steel is the intermediate universal rolling mill 5, the flange width and flange piece width are the edger rolling mill 9, and the in-web method is the oblique roll rolling mill 7 and the variable body width horizontal roll. With the finishing universal rolling mill 8 incorporating the above, the rolling rolls can be manufactured separately without rearranging. In the following, for the sake of explanation, the steel materials on the production line L may be collectively referred to as "rolled materials".

By the way, the edger rolling mill 9 has a function of rolling down the width of the flange portion 12 of the material to be rolled and forging or shaping the end face thereof, as well as the center of the thickness of the web portion 10 of the material to be rolled. It has a so-called web center position correction function that corrects the width center position of the flange portion 12.

FIG. 11 shows a situation in which the web center position of the material to be rolled is corrected by the edger rolling mill 9 incorporating the most basic upper and lower edger roll pairs 9a and 9b that have been used for a long time. FIG. 11A is a cross-sectional view of edger rolling viewed from the side surface (parallel to the roll axis), and the material M to be rolled is traveling from right to left. The cross sections (exit cross sections) OO of the upper and lower edger roll pairs 9a and 9b just below the roll axis are shown in (b), and the cross sections BB on the entry side and the cross sections AA upstream thereof are shown in (c) and (d). ). Before edginger rolling, for example, as shown in (d), the material M to be rolled has a web center bias (deviation of the thickness center of the web portion with respect to the width center position of the flange portion) with respect to the width center position of the flange portion 12. It is assumed that the thickness center of the web portion 10 is shifted upward by s. In this case, as shown in (c), the flange portion 12 of the material M to be rolled is formed by the upper and lower tip portions thereof due to the flange width pressure lower portions 9a-2 and 9b-2 of the upper and lower edger roll pairs 9a and 9b in the cross section BB. Is restrained, and the web restraint portion 9a-1 of the upper roll 9a comes into contact with the web portion 10 of the material M to be rolled before the web restraint portion 9b-1 of the lower roll 9b. Then, as the vertical roll gap closes toward the outlet cross section OO, the flange portion 12 of the material M to be rolled is widened by the flange width compression lower portions 9a-2 and 9b-2 of the vertical edger roll pairs 9a and 9b. As it is rolled down, the web portion 10 is pushed downward by the web restraint portion 9a-1. During this time, the connecting portion between the flange portion 12 and the web portion 10 is sheared by the pushing force Pw, the center of the thickness of the web portion 10 moves toward the center position of the width of the flange portion 12, and the web portion 10 in the outlet cross section OO. The web restraint portion 9b-1 of the lower roll 9b also comes into contact with. Through such a process, the s value becomes 0 and the web center position correction is completed. In edger rolling, as shown in (a), the force of P1 in the downward direction and P2 in the upward direction acts on the flange portion 12 from the edger roll pairs 9a and 9b, and the web. The force of Pw acts downward on the portion 10, and there is a relationship of the following equation (1) from the balance of the forces.
P2-P1 = Pw ... (1)

It is extremely important to reduce the web center bias of H-beams and improve the web center position accuracy from both the productivity of rolling molding and the product quality, and to manufacture intermediate materials and products with a small web center bias. , Various edger rolling mills have been devised so far. For example, in Patent Document 1, an eccentric ring is rotatably provided via a bearing on an outer peripheral surface close to the working surface (that is, the lower part of the flange width pressure) of the vertical roll of the edger rolling mill in the axial direction. Disclosed is a configuration of an edger rolling mill in which a web restraint ring roll (that is, a web restraint portion) is rotatably provided on the outer peripheral surface of the eccentric ring via a bearing concentrically with the outer circle of the eccentric ring. In this edger rolling mill, the clearance (difference between the web restraint ring roll gap of the upper and lower rolls and the web thickness of the material to be rolled) can be set to 0 even if the flange piece width of the material to be rolled is different. As a result, the flange width and the flange piece width of the material to be rolled can be made separately with high web center position accuracy without rearranging the upper and lower edger roll pairs.

FIG. 12 shows a situation in which the web center position of the material to be rolled is corrected by the edger rolling mill 9 incorporating the upper and lower edger roll pairs 9a and 9b based on Patent Document 1. The principle of correcting the center position of the web is the same as in FIG. 11, but the flange width rolling lower portions 9a-2 and 9b-2 and the web restraint portions 9a-1 and 9b-1 are not integrated, and the rotation of the eccentric ring (not shown) By adjusting the position, each can move independently, and even if the flange piece width of the material M to be rolled is different, the clearance can be set to 0.

Further, in Patent Document 2, an eccentric ring is provided on the drive shaft, and the outer surface width of the web restraint ring roll (that is, the web restraint portion) is formed to be larger than the flange piece width of the material to be rolled. Avoids the configuration where the inner peripheral surface of the web restraint ring roll and the sliding surface of the eccentric ring are located inside the flange, and prevents scale, cooling water, dust, etc. from entering the gaps between the roll members. The technology to be rolled is disclosed. This Patent Document 2 is an improved invention of the above Patent Document 1.

Further, Patent Document 3 enables fine adjustment of the relative axial position of the edging roll (that is, the lower part of the flange width compression) with respect to the eccentric ring, and the web restraint ring roll (that is, the entire inner surface of the flange portion) is covered. The structure is such that the web restraint portion) and the eccentric ring come into contact with each other to avoid problems such as the material to be rolled floating, making it difficult for the flange portion to buckle, and making the shape of the flange portion (particularly the tip portion). The technology to make it normal is disclosed. This Patent Document 3 is also an improved invention of the above Patent Document 1.

Further, in Patent Document 4, as shown in FIG. 13, the edger rolling mill is a 4-roll universal type, and the principle of correcting the web center position is the same as that of FIG. 11, but the edger is rolled by the vertical roll pairs 9c and 9d. Disclosed is a technique for restraining the outer side of a flange of a material and performing width rolling on the flange in a state where the flange is less likely to buckle.

Further, in Patent Document 5, the edger rolling mill is provided with an upper roll pair and a lower roll pair that are vertically symmetrical with respect to the pitch line, and the upper roll pair is symmetrical with respect to the center of the rolling mill. The lower roll pair consists of a lower left roll and a lower right roll that are symmetrical with respect to the center of the rolling mill, and the roll axes of the upper left roll, the upper right roll, the lower left roll and the lower right roll are A technique is disclosed in which the rolls are inclined by the same angle as the inclination angle of the flange portion of the material to be rolled that the rolls come into contact with during rolling.

Special Fair 5-32128 Gazette Special Fairness 7-41294 Japanese Unexamined Patent Publication No. 63-6008 JP-A-9-108704 Japanese Unexamined Patent Publication No. 2016-144811

However, in the techniques described in Patent Documents 1 to 3, the outer flange portion of the material to be rolled is not constrained, so that the flange portion may buckle when the flange width is reduced. When the flange is buckled, the flange width reduction efficiency of edger rolling decreases (for example, even if the width is reduced, the width returns to the original when the plate thickness reduction is applied in the subsequent universal rolling pass), or the web center position. Accuracy and flange width accuracy are reduced. In particular, since the tail end portion of the material to be rolled is weakly restrained from the surroundings, the flange portion tends to buckle when the tail end is pulled out even if the flange width reduction amount is small, and such a problem is likely to occur. Further, since the outer side portion of the flange is not restrained, the inner surface of the flange portion 12 is from the side surface portion of the web restraint portions 9a-1 and 9b-1 of the upper and lower edger roll pairs 9a and 9b in the outlet cross section OO as shown in FIG. There is a concern that the web portion 10 will bend locally near the boundary without shear deformation at the boundary between the flange portion 12 and the web portion 10 and the web center position correction function will be insufficient.

In addition, the thickness of the flange portion locally increases (bulging occurs) as the width of the flange portion is reduced by edger rolling. If the material to be rolled has a web center bias on the entry side of edger rolling, a difference will occur between the bulging δ1 and δ2 of the upper and lower flange portions on the exit side as shown in FIGS. 11 (b) and 12 (b). The mechanism will be described later.

When a material to be rolled with a bulging difference between the upper and lower flanges is subjected to plate thickness reduction in the subsequent universal rolling pass, the vertical difference in the vertical component of the frictional force received by the inner side surface of the flange from the horizontal roll side surface causes the vertical difference. The flange portion moves in the vertical direction, which reduces the accuracy of the web center position. This situation will be described with reference to FIG. FIG. 15 shows a state in which the material M (first intermediate material 14 or second intermediate material 15) to be rolled is rolled by the finishing universal rolling mill 8 to form an H-shaped steel product 16. FIG. 15A is a cross-sectional view of the finished universal rolling viewed from the side surface (parallel to the horizontal roll axis), and the material M to be rolled is traveling from right to left. The exit cross section OO of FIG. 15 (a) is shown in (b), and the cross section BB on the entrance side and the cross section AA upstream of the cross section BB are shown in (c) and (d). As shown in (d), it is assumed that the upper flange of the material M to be rolled has bulging δ1 and the lower flange has bulging δ2, and δ1 <δ2. In the cross section BB, as shown in (c), the left and right vertical roll pairs 64 and 65 press the outer portion of the flange portion 12 of the material M to be rolled and are between the horizontal rolls 60a, 60b, 61a and 61b. The thickness rolling starts at. When the thickness of the flange portion 12 is reduced, a reaction force acts on the roll surface. Therefore, as shown in FIG. 15A, a frictional force from the side surface portions of the horizontal rolls 60a, 60b, 61a, 61b in the circumferential direction of the side surface portions. Ft and Fb act. Ft is a frictional force acting diagonally downward from the upper rolls 60a and 60b to the inner portion of the flange portion 12 of the material M to be rolled, and Fb is an inner portion from the lower rolls 61a and 61b to the flange portion 12 of the material M to be rolled. It is a frictional force that acts diagonally upward. Since δ1 <δ2, Ft <Fb, and the vertical components Fty and Fby of Ft and Fb also have a relationship of Fty <Fby. Therefore, the flange portion 12 moves upward toward the outlet cross section OO, and in the outlet cross section OO, the width center position of the flange portion 12 is higher than the plate thickness center of the web portion as shown in FIG. 15 (b). It comes to be located in, and the web center bias s occurs.

Next, if the technique described in Patent Document 4 is applied, buckling of the flange portion and local bending of the web portion are less likely to occur due to the support of the vertical roll with respect to the outer side portion of the flange. However, since the vicinity of the tip of the flange portion is not constrained in the plate thickness direction, bulging occurs at the tip of the flange portion as the flange width is reduced by edger rolling. If the material to be rolled has a web center bias, a difference will occur between the bulging of the upper and lower flanges as described above, and a web center bias will occur when plate thickness rolling is applied in the subsequent universal rolling pass.

Here, with reference to FIG. 11, if the material to be rolled has a web center bias on the entry side of edger rolling, a mechanism in which a difference occurs between the bulging of the upper and lower flange portions will be described (the same description will be given in FIGS. Is possible). As shown in FIG. 11A, the radius of the flange width pressure lower portions 9a-2 and 9b-2 of the vertical horizontal roll pairs 9a and 9b is r, the radius of the web restraint portion 9a-1 is R, and the flange width pressure lower portion 9a. Let Δh1 be the flange width reduction amount due to -2, and Δh2 be the flange width reduction amount due to the flange width pressure lower portion 9b-2. Further, the load acting on the flange portion 12 from the flange width pressure lower portion 9a-2 acts on P1, the load acting on the flange portion 12 from the flange width pressure lower portion 9b-2 acts on P2, and the load acting on the web restraint portion 9a-1 acts on the web portion 10. Let Pw be the load to be applied. It is considered that P1 and P2 are proportional to the projected contact arc lengths ld1 and ld2 under the flange width reduction shown in FIG. 11A, respectively, and the following equations (2) and (3) are established.
P1 ∝ ld1 ≒ (2rΔh1) ^1/2 ... (2)
P2∝ld2≈ (2rΔh2) ^1/2 ... (3)
Further, Pw is considered to be proportional to the projected contact arc length ld of the web restraint portion 9a-1 with respect to the web surface shown in FIG. 11A, and the web portion 10 is covered on the entry side before reaching the exit cross section OO. Since the rolled material M receives a pressure equal to the web center bias s, the following equation (4) holds.
Pw∝ld ≒ (2Rs) ^1/2 ... (4)
Considering the above equation (1) in the above equations (2), (3), and (4), it can be seen that the following equation (5) holds.
(Δh2) ^1/2 − (Δh1) ^1/2
∝ (s ・ R / r) ^1/2・ ・ ・ (5)

On the other hand, the bulging δ1 and δ2 shown in FIG. 11B are considered to be proportional to the flange width reduction amounts Δh1 and Δh2, respectively, and the following equations (6) and (7) hold.
δ1∝Δh1 ・ ・ ・ (6)
δ2∝Δh2 ・ ・ ・ (7)
That is, from the above equations (5), (6), and (7), the following equation (8) holds.
(Δ2) ^1/2 − (δ1) ^1/2
∝ (s ・ R / r) ^1/2・ ・ ・ (8)
From the above formula (8), if the material M to be rolled has a web center bias s on the entry side of edger rolling, a difference occurs between the bulgings δ1 and δ2 of the upper and lower flange portions. Therefore, with respect to the techniques disclosed in Patent Documents 1 to 4, it is unavoidable that a bulging difference occurs between the flange portions due to the correction of the web center position of the material to be rolled.

Next, the technique of Patent Document 5 is a cantilever 4-roll type in which the hole-shaped roll shape is made into a bag shape and the roll shaft is inclined by the same angle as the inclination angle of the flange-corresponding portion of the material to be rolled. The entire flange portion of the rolled material is wrapped so that the flange portion does not bulge. This solved the problem of creating a bulging difference between the flanges. However, since the bulging of the flange portion due to the reduction of the flange width is restrained by the roll surface of the bag hole, the roll surface receives a strong internal pressure from the inner and outer portions of the flange. Since the roll shaft is inclined by the same angle as the inclination angle of the flange corresponding portion, the roll surface moves in the tangential direction of the flange surface to be restrained, so that the flange portion of the material to be rolled seizes on the roll surface and causes scratches. There is a problem that it is easy to occur.

It is extremely important to improve the productivity and product quality of rolling molding of H-shaped steel, and in view of the above circumstances, the object of the present invention is to focus on the web of the intermediate material with respect to the intermediate material in the rolling process of H-shaped steel. It is an object of the present invention to provide a web center position correction rolling mill and a rolling method for H-beams for correcting the position.

In order to achieve the above object, according to the present invention, with respect to the material to be rolled, which is an intermediate material in the rolling process of H-shaped steel, the center of the thickness of the web portion of the material to be rolled is positioned at the center of the width of the flange portion. It is a web center position correction rolling mill that corrects to, and is provided with a vertically symmetrical horizontal roll pair and a left-right symmetrical vertical roll pair, and the horizontal roll pair corresponds to the flange tip of the side surface portion of the horizontal roll pair. A web center position correction rolling mill is provided in which a relief portion is provided in the vicinity of the portion, and a flange for restraining a flange tip portion of a material to be rolled is provided in the vertical roll pair.

The horizontal roll pair is configured by dividing both the upper roll and the lower roll into left and right pairs.
The distance between the left and right pairs may be freely changed.

The vertical roll pair is configured by dividing both the left roll and the right roll into upper and lower pairs.
The distance between the upper and lower pairs may be freely changed.

Further, according to the present invention from another viewpoint, the web center position correction rolling mill described above is arranged in front of the finishing rolling mill, and is formed from the material through rough rolling, intermediate universal rolling, and edger rolling. After the intermediate material or the intermediate material formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling is passed through the roll gap of the web center position correction rolling mill to correct the web center position. Provided is a method for rolling an H-shaped steel, which comprises performing universal rolling for finishing to produce an H-shaped steel product.

Further, according to the present invention, the web center position correction rolling mill described above is arranged in front of the finishing rolling mill, and an intermediate material formed from the material through rough rolling, intermediate universal rolling, and edger rolling, or an intermediate material, or With respect to intermediate materials formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling, the left and right pairs of the upper roll and lower roll of the horizontal roll pair correspond to the in-web dimensions of the intermediate material. The roll gap of the horizontal roll pair and the peripheral portion of the side surface portion of the horizontal roll pair and the circumferential portion of the vertical roll pair are adjusted according to the thickness dimensions of the web portion and the flange portion of the intermediate material. By adjusting the gap, the intermediate material is passed through the web center position correction rolling mill under the condition that the in-web method of the cross section of the intermediate material and the rolling reduction of the flange width and the flange thickness are 1% or less. Provided is a method for rolling H-shaped steel, which comprises performing universal rolling for finishing after correcting the position to produce an H-shaped steel product.

Further, according to the present invention, the web center position correction rolling mill described above is arranged in front of the finishing rolling mill, and an intermediate material formed from the material through rough rolling, intermediate universal rolling, and edger rolling, or an intermediate material, or With respect to the intermediate material formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling, the upper and lower left rolls and right rolls of the vertical roll pair correspond to the flange width dimension of the cross section of the intermediate material. By adjusting the distance between the pairs, the roll gap of the horizontal roll pair and the peripheral portion of the side surface portion of the horizontal roll pair and the circumferential portion of the vertical roll pair are adjusted according to the thickness dimensions of the web portion and the flange portion of the intermediate material. The intermediate material is passed through the web center position correction rolling mill under the condition that the in-web method of the cross section of the intermediate material and the rolling reduction of the flange width and the flange thickness are 1% or less. Provided is a method for rolling an H-shaped steel, which comprises correcting the center position and then performing a universal finish rolling to produce an H-shaped steel product.

The taper angle of the side surface portion of the horizontal roll pair that abuts on the inner side of the flange of the intermediate material and the taper angle of the circumferential portion of the vertical roll pair that abuts on the outer side of the flange of the intermediate material are determined by the intermediate material. It may be set smaller than the flange inclination angle, and the web center position of the intermediate material may be corrected while reducing the inclination angle of the flange portion of the intermediate material.

According to the present invention, the web center bias that is difficult to avoid in universal rolling of H-section steel, that is, the deviation of the flange portion at the center of the plate thickness of the web portion of the material to be rolled from the width center portion of the H-section steel is corrected. It is possible to improve the productivity and product quality of rolling molding.

It is explanatory drawing which shows two examples of (a) and (b) about the manufacturing line of H-shaped steel which concerns on the implementation of the technique of this invention. It is explanatory drawing which shows the web center position correction process of the material to be rolled by the web center position correction rolling mill which concerns on the practice of this invention, (a) is from the side surface of the web center position correction rolling mill (parallel to a horizontal roll axis. ) It is a cross-sectional view seen, (b) shows an exit cross section OO, (c) shows a cross section BB on the entrance side, and (d) shows a cross section AA upstream thereof. It is explanatory drawing which shows the web center position correction process of the material to be rolled by the web center position correction rolling mill which accompanies the change of the flange angle which concerns on the implementation of the present invention, (a) is from the side of the web center position correction rolling mill. It is a cross-sectional view (parallel to the horizontal roll axis), (b) is an exit cross section OO, (c) is a cross section BB on the entry side, and (d) is an upstream cross section AA. Shown. It is explanatory drawing which shows the exit cross section of the web center position correction rolling mill when the web center position of the material to be rolled which has a different flange width is corrected, (a) is (b) when the flange width of the material to be rolled is wide. Indicates when the flange width of the material to be rolled is narrow. It is explanatory drawing which shows the outlet cross section of the web center position correction rolling mill at the time of correcting the web center position of the material to be rolled which the flange width and the web height are different, and (a) is the web with a wide flange width of the material to be rolled. When the height is small, (b) is when the flange width of the material to be rolled is narrow and the web height is small, and (c) is when the flange width of the material to be rolled is wide and the web height is large (d). Indicates when the flange width of the material to be rolled is narrow and the web height is large. It is explanatory drawing which shows the roll (vertical horizontal roll pair and left and right vertical roll pair) of the web center position correction rolling mill which concerns on the practice of this invention, (a) is the roll of the basic shape, (b) is the vertical roll up and down. The split type, (c) shows a vertical roll divided into upper and lower parts and a horizontal roll divided into left and right types. The right half of the material to be rolled indicates that the process of correcting the web center position of the material to be rolled by the web center position correction rolling mill according to the implementation of the present invention proceeds in the order of (a), (b), and (c). It is explanatory drawing which shows the cross section of (a), (a) is the sectional view which the flange part of the material to be rolled is introduced into the space between the upper and lower flanges of a vertical roll, (b) is the upper and lower tip part of a flange part. It is a cross-sectional view at the moment when they are in contact with and restrained by the upper and lower flanges, respectively, and (c) shows a cross section (exit cross section) just below the roll axis of the web center position correction rolling mill. It is explanatory drawing which shows one of the defects in the process of correcting the web center position of the material to be rolled by the web center position correction rolling mill which concerns on the practice of this invention, and the upper and lower tip portions of the flange part are equal to the upper and lower flanges of a vertical roll. It shows the situation where it collapses and is introduced without being restrained by. This data is the basis for obtaining the appropriate range of conditions for the in-web legal reduction rate, flange width reduction rate, and flange thickness reduction rate based on the web center position correction test related to the implementation of the technique of the present invention. Under (a) being 0%, (b) being 1.0%, and (c) being 1.5%, the stability of web center position correction when the flange width reduction rate and the flange thickness reduction rate are changed. It is explanatory drawing which shows. It is explanatory drawing which shows two examples of (a) and (b) about the conventional H-section steel production line. It is explanatory drawing which shows the web center position correction process of the material to be rolled by the edger rolling mill of the conventional H-section steel, and (a) is the cross-sectional view seen from the side surface of edger rolling (parallel to the horizontal roll axis). (B) shows the exit cross section OO, (c) shows the cross section BB on the entrance side, and (d) shows the upstream cross section AA. The process of correcting the web center position of the material to be rolled by an H-shaped steel edger rolling mill in which the web restraint portion of the horizontal roll and the lower part of the flange width compression are moved independently by adjusting the rotation position of the eccentric ring. (A) is a cross-sectional view seen from the side surface of edger rolling (parallel to the horizontal roll axis), (b) is an exit cross section OO, and (c) is a cross section on the entry side. BB and (d) show the cross sections AA upstream of the BB. It is explanatory drawing which shows the process of correcting the web center position of the material to be rolled by the edger rolling mill of the H-section steel which arranged the vertical roll in the past, and (a) is seen from the side surface of edger rolling (parallel to the horizontal roll axis). It is a cross-sectional view, (b) is an exit cross section OO, (c) is a cross section BB on the entrance side, and (d) is an upstream cross section AA. It is explanatory drawing which shows the local bending of the web part which occurs when the web center position of the material to be rolled is corrected by the edger rolling mill of H-section steel which does not arrange a vertical roll. It is explanatory drawing which shows the process that the web center bias s occurs when there is a bulging difference between the upper and lower flange portions, and the bulging δ2 of the lower flange portion is larger than the bulging δ1 of the upper flange portion, and (a) is a side surface of edger rolling. It is a cross-sectional view seen from (parallel to the horizontal roll axis), (b) is an exit cross section OO, (c) is a cross section BB on the entrance side, and (d) is an upstream cross section AA. Is shown. It is explanatory drawing which shows the state of edger rolling when the flange width pressure lower part of the horizontal roll of an edger rolling mill has a huge diameter. It is explanatory drawing which shows that when the flange inclination angle of the material to be rolled (intermediate material) which bites into a finish rolling mill is large, the biting posture of a material to be rolled collapses, and (a) is the flange inclination angle of a material to be rolled. When it is small, (b) indicates when the flange inclination angle of the material to be rolled is large.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals to omit duplicate description.

FIG. 1 is an explanatory diagram of an H-section steel production line L including the rolling equipment 1 according to the present embodiment. Regarding FIG. 1A, in order from the upstream side, the heating furnace 3, the rough rolling mill 4, the intermediate universal rolling mill 5, the edger rolling mill 9 and the web center are close to the intermediate universal rolling mill 5 in the production line L. The position correction rolling mill 19 and the finishing universal rolling mill 8 are arranged. Further, in FIG. 1B, in-web widening rolling is performed by the oblique roll rolling mill 7 between the edger rolling mill 9 and the web center position correction rolling mill 19.

In the following, the rolling of the material to be rolled in each rolling mill shown in FIG. 1 will be described with reference to the drawings. The heating furnace 3, the rough rolling mill 4, the intermediate universal rolling mill 5, the edger rolling mill 9, the diagonal roll rolling mill 7, and the finishing universal rolling mill 8 are the same as those conventionally used for manufacturing shaped steel. Since the configuration is known, the description thereof is omitted in the present specification.

FIG. 6 is an explanatory view showing the rolls (vertical horizontal roll pairs 19a, 19b and left and right vertical roll pairs 19c, 19d) of the web center position correction rolling mill 19 according to the implementation of the technique of the present invention, and FIG. 6A is an explanatory view of a basic shape. Rolls, (b) shows a vertical roll divided into upper and lower parts, and (c) shows a vertical roll divided into upper and lower parts and a horizontal roll divided into left and right types. Regarding (a), the first intermediate material 14 formed by the intermediate universal rolling mill 5-edger rolling mill 9 or the second intermediate material 15 formed by the oblique roll rolling mill 7 is used as the rolled material. The rolled material is introduced into the H-shaped roll gap formed by the horizontal roll pairs 19a and 19b and the left and right vertical roll pairs 19c and 19d. In (b), the left and right vertical roll pairs 19c and 19d of the left roll 19c and the right roll 19d are divided into upper and lower pairs 19c1 and 19c2 and upper and lower pairs 19d1 and 19d2, respectively, and the spacing between the upper and lower pairs can be changed freely. This makes it possible to handle materials to be rolled with different flange widths. In addition to this, in (c), the upper and lower horizontal roll pairs 19a and 19b are divided into left and right pairs 19a1, 19a2 and left and right pairs 19b1 and 19b2, respectively, and the distance between the left and right pairs can be changed freely. It is configured so that it can handle materials to be rolled with different flange widths and web heights.

In FIGS. 6A, 6B and 6C, the horizontal roll pairs 19a (or 19a1, 19a2) and 19b (or 19b1, 19b2) are released to the vicinity of the flange tip corresponding portion of the side surface portion of the horizontal roll pair. Sections 19-1 are provided, and the vertical roll pairs 19c (or 19c1, 19c2) and 19d (or 19d1, 19d2) are provided with flanges 19-2 at both ends in the axial direction of the vertical roll. The flange 19-2 of the vertical roll pair is for contacting and restraining the flange tip portion of the material to be rolled and fixing the material to be rolled in the vertical direction, and is a relief portion of the side surface portion of the horizontal roll pair. Reference numeral 19-1 is provided so that the flange 19-2 of the vertical roll pair and the side surface portion of the horizontal roll pair do not interfere with each other. Due to this relief portion 19-1, the horizontal roll side surface portion does not come into contact with the vicinity of the tip portion of the inner flange portion of the material to be rolled. Further, the vertical roll pairs 19c (or 19c1, 19c2) and 19d (or 19d1, 19d2) have a circumferential portion that abuts on the outer side of the flange of the material to be rolled and restrains the portion other than the flange 19-2. 19-4 is provided, and the horizontal roll pairs 19a (or 19a1, 19a2) and 19b (or 19b1, 19b2) have a circumferential portion 19 that abuts and restrains the entire or part of the web surface of the material to be rolled. -3 is provided.

Next, a rolling method using the web center position correction rolling mill will be described with reference to FIG. FIG. 2 is an explanatory view showing a web center position correction process of the material M to be rolled by the web center position correction rolling mill 19, and (a) is a side view of the web center position correction rolling mill 19 (parallel to the horizontal roll axis). It is a cross-sectional view as seen, (b) is an exit cross section OO, (c) is a cross section BB on the entrance side, and (d) is an upstream cross section AA. As shown in (d), the material to be rolled (the intermediate material) M has a web center bias s on the entry side, and in the figure, the plate thickness center of the web portion 10 is s above the width center position of the flange portion 12. It is in. Further, the flange portion 12 is inclined by α with respect to the vertical direction (hereinafter, referred to as a flange inclination angle). As the roll gap closes toward the exit cross section OO, the tip of the flange portion 12 of the material to be rolled M is moved up and down by the vertical roll pair 19c and 19d flange 19-2 as shown in FIG. 2C. Be bound by. Immediately after that, the upper horizontal roll 19a contacts the upper surface of the web portion 10 of the material M to be rolled and pushes down the web portion 10 downward to correct the web center position. Then, in the exit cross section OO, as shown in FIG. 2B, the entire outer portion of the flange is supported by the vertical roll pairs 19c and 19d, and the horizontal roll pairs 19a and 19b are the circles at the same time. The web portion 10 of the material M to be rolled is shaped from above and below by the peripheral portion 19-3. In such a rolling process, the entire outer side of the flange portion 12 of the material M to be rolled is restrained by the vertical roll pair 19c and the circumferential portion 19-4 of 19d, so that the flange portion 12 is less likely to buckle, and FIG. Such local bending of the web portion does not occur, shear deformation occurs at the boundary between the flange portion 12 and the web portion 10, and the web center position is efficiently corrected.

On the other hand, since the side surface portions of the horizontal roll pairs 19a and 19b do not come into contact with the vicinity of the tip end portion of the flange inner portion of the material M to be rolled, it is inevitable that bulging occurs at the tip end portion of the flange portion 12. However, the bulging δ1 of the upper flange and the bulging δ2 of the lower flange can be suppressed to be small, and the difference between the two δ2-δ1 can also be reduced. The reason will be described below.

The reason why the bulging δ1 and the bulging δ2 can be suppressed to be small is that the radius of curvature of the pressing surface of the vertical roll pair 19c and 19d that restrains the flange tip portion of the material M to be rolled is very large. That is, the value of r on the right side of the above equation (8) is very large and r >> R. In that case, the value of the right side of the above equation (8) is small, and therefore the bulging difference δ2-δ1 between the upper and lower flange portions. The value is small. When a horizontal roll pair of a conventional edger rolling mill as shown in FIG. 11 is used to correct the web center position, the value of δ2-δ1 becomes large because r <R. When r is large, as shown in FIG. 16, the contact arc lengths ld1 and ld2 under the flange width pressure due to the upper and lower flange width pressure lower parts increase, and the loads P1 and P2 applied to the tip of the flange portion 12 increase, so that the reduction amount Δh1 , Δh2 cannot be increased. Therefore, the web center position correction rolling mill 19 of the present invention does not positively reduce the flange width, so that the bulging values δ1 and δ2 are small. Therefore, the web center bias due to the mechanism already described with reference to FIG. 15 hardly occurs. The reduction rate of the flange width is 1% or less, and in order to stabilize the process of correcting the center position of the web, it is not preferable to buckle the web significantly, and the reduction rate of the in-web method is also 1% or less. Further, the reduction of the flange thickness is also a light reduction of 1% or less in order to adjust the shape. The grounds for this will be explained below.

The web center position correction process of the material M to be rolled by the web center position correction rolling mill proceeds in the order of (a), (b), and (c) of FIG. FIG. 7 shows a cross section of the right half of the material to be rolled M for simplicity. (A) is a cross-sectional view in which the flange portion 12 of the material M to be rolled is introduced into the space between the upper and lower flanges 19-2 of the vertical roll, and (b) is the upper and lower tip portions of the flange portion 12 respectively. It is a cross-sectional view at the moment of contacting and restraining the flange of the above, and (c) shows a cross section (exit cross section) just below the roll axis of the web center position correction rolling mill.

On the entry side, as shown in FIG. 7A, the dimensions of the material M to be rolled are the in-web method Hi, the flange width Fit + Fib (because there is a web center bias s, the upper flange width Fit and the lower flange width Fib are generally Different), flange thickness hfi. As shown in FIG. 7 (b), the upper and lower tips of the flange portion 12 of the material M to be rolled are restrained by the upper and lower flanges 19-2 of the vertical roll 19d to stop the vertical movement, and then the roll gap is closed. As it goes, the in-web method, flange width and flange thickness are reduced, and as shown in FIG. 7C, the cross section (exit cross section) just below the roll axis of the web center position correction rolling mill shows the in-web method Ho, flange width Fo, and flange. The thickness is hfo, and the bias toward the center of the web is eliminated. Ho is equal to the body width of the upper and lower pairs 19a and 19b of the horizontal roll. At this time, the in-web method, the flange width, and the reduction rate of the flange thickness are defined by the following equations (9), (10), and (11), respectively.
In-web reduction rate = (Hi-Ho) / Hi × 100 (%) ・ ・ ・ (9)
Flange width reduction rate = (Fit + Fib-Fo) / (Fit + Fib) x 100 (%) ... (10)
Flange thickness reduction rate = (hfi-hfo) / hfi × 100 (%) ・ ・ ・ (11)

The magnitudes of the in-web reduction rate, the flange width reduction rate, and the flange thickness reduction rate defined by the above formulas (9), (10), and (11) are shown in FIGS. 7 (a), (b), and (c). It greatly affects the stability of the deformation process as described above, and all of them are more stable as they are closer to 0. In particular, the negative value defined by the above equation (9) is more stable for the in-web reduction rate.

As shown in FIG. 7B, the upper and lower tip portions of the flange portion 12 of the material M to be rolled are constrained by the upper and lower flanges 19-2 of the vertical roll 19d to stop the movement in the vertical direction with the roll surface. There are gaps A, B, and C between them. The larger these gaps are, the more unstable the deformation process is, and the larger the in-web reduction rate, the flange width reduction rate, and the flange thickness reduction rate are, the larger these gaps are. If the gap is large, the flange portion 12 will fall and the web will bend, as shown in FIG. 8, for example. In this state, the outer portion of the flange portion 12 cannot be uniformly restrained in the flange width direction by the circumferential portion 19-4 of the vertical roll 19d in the exit cross section, which hinders the correction of the web center position. ..

Therefore, the present inventors conducted a web center position correction test in which the in-web reduction rate, the flange width reduction rate, and the flange thickness reduction rate were changed for H-shaped steels of several sizes, and the flange portion as shown in FIG. We decided to find a condition to prevent the 12 or the web part 10 from falling or deforming. The test materials were H900 x 300 x 16/28 (web height 900 mm, web inner method 844 mm, web thickness 16 mm, flange thickness 28 mm), H600 x 200 x 11/17 (web height 600 mm, web inner method 566 mm). A hot rolling experiment was carried out using a steel material having a web thickness of 11 mm and a flange thickness of 17 mm) immediately before finish rolling, and therefore a flange inclination angle of 6 degrees. At this time, a material was produced in which the web center bias s was 2 mm and the center of the web plate thickness was shifted upward by 2 mm with respect to the center position of the flange width.

The results of the above test are shown in FIG. In FIG. 9 (a), the in-web rolling rolling ratio was set to 0%, (b) was 1.0%, and (c) was 1.5%, and the test was performed by changing the flange width rolling ratio and the flange thickness rolling reduction. It was divided into the case where the defect as shown in FIG. 8 did not occur in the material to be rolled (○, ●) and the case where the defect occurred (Δ, ▲). From FIG. 9, when the in-web reduction rate is 1.0% or less, the flange width reduction rate is 1.0% or less, and the flange thickness reduction rate is 1.0% or less, the web center position correction is almost stable. You can see that you can do it. Therefore, regarding the correction of the center position of the web, in order to perform it stably, the reduction rate of the plate thickness and the plate width should be reduced extremely lightly at 1.0% or less, or the conditions should be such that the reduction is hardly performed. It can be said that.

As described above, in the manufacturing technique of the H-shaped steel using the web center position correction rolling mill 19 described with reference to FIGS. 1, 2 and 6, the intermediate material (first intermediate material 14) in the rolling process of the H-shaped steel Alternatively, it is possible to efficiently correct the bias of the center of the web with respect to the second intermediate material 15), and improve the productivity and product quality of rolling molding of H-shaped steel.

Although an example of the embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the ideas described in the claims, and these also naturally belong to the technical scope of the present invention. It is understood as a thing.

Other embodiments of the present invention will be described with reference to FIG. As shown in FIG. 3D, the material to be rolled (the intermediate material) M has a web center bias s on the entry side, and the flange portion 12 is inclined by α with respect to the vertical direction in FIG. Is similar to. The differences are the taper angles of the side surface portions of the horizontal roll pairs 19a and 19b that abut the inner flange portion of the material M to be rolled, and the circumferences of the vertical roll pairs 19c and 19d that abut the outer flange portion of the material M to be rolled. The taper angle of the portion 19-4 is set to β (<α) smaller than the flange inclination angle of the material M to be rolled, and the intermediate material is reduced to β while reducing the inclination angle of the flange portion of the material M to be rolled. This is a point of correcting the center position of the web, and this technique also falls within the scope of the technique of the present invention.

According to the form shown in FIG. 3, the material to be rolled (intermediate material) M is engaged with the finishing universal rolling mill 8 by reducing the flange inclination angle to obtain the accuracy of the web center position in the finishing universal rolling. The decrease can be suppressed. FIG. 17 compares (a) when the flange inclination angle of the material M to be rolled is small and (b) when the flange inclination angle is large. When the flange inclination angle of the material M to be rolled is large (b), the vertical roll pairs 64 and 65 start pressing the outer side of the flange at a position farther upstream from the outlet cross section than in (a) where the flange inclination angle is small. .. Therefore, since the gap gh between the vertical pairs 60a, 61a, 60b, and 61b of the horizontal roll at that time is large, the material to be rolled M is loosely restrained in the vertical direction with respect to the web portion 10, and the material to be rolled is as shown in (b). The biting posture of M collapses, and the risk of web center bias occurring again in finish universal rolling increases. In finish universal rolling, it is desirable to suppress the reduction of the flange inclination angle as much as possible, and in that sense, the reduction of the flange inclination angle by the web center position correction rolling mill 19 is effective.

Further, the web center position correction rolling mill 19 can be made size-free, and as shown in FIG. 4, the vertical rolls are vertically divided into upper and lower pairs, and the distance c between the upper and lower pairs is changed. Therefore, it is possible to handle materials to be rolled with different flange widths. Further, as shown in FIG. 5, the horizontal roll is also divided into left and right to form a left and right pair, and by changing the distance d between the left and right pairs, it is possible to cope with the material to be rolled with different web heights. These also belong to the technical scope of the present invention.

The present invention relates to an apparatus and a method for correcting the web center position of an H-beam produced by rolling. Specifically, the present invention relates to a material to be rolled immediately before finishing universal rolling immediately after intermediate rolling. It can be applied to a modified rolling mill for modifying the web center position of a material and a rolling method for H-beams.

1 ... Rolling equipment 3 ... Heating furnace 4 ... Rough rolling mill 5 ... Intermediate universal rolling mill 7 ... Diagonal roll rolling mill 8 ... Finishing universal rolling mill 9 ... Edger rolling mill 9a, 9b ... Top and bottom pairs of horizontal rolls of edger rolling mill 9a-1, 9b-1 ... Upper and lower pairs of web restraints on the horizontal roll of the edger rolling mill 9a-2, 9b-2 ... Upper and lower pairs of flange width pressure lower part of the horizontal roll of the edger rolling mill 9c, 9d ... Edger rolling mill Left and right pair of vertical rolls 10 ... Web part of H-shaped cross section 11 ... Rectangular cross-section slab 12 ... Flange part of H-shaped cross section 13 ... H-shaped rough-shaped material 14 ... First intermediate material (intermediate universal rolling mill and edger rolling mill) Immediately after rolling and modeling)
15 ... Second intermediate material (immediately after widening the in-web method with a diagonal roll rolling mill)
16 ... H-shaped steel product 17 ... Third intermediate material (immediately after the web center position of the material to be rolled is corrected by the web center position correction rolling mill)
19 ... Web center position correction rolling mill 19a, 19b ... Web center position correction rolling machine horizontal roll top and bottom pair 19a1, 19a2 ... Web center position correction rolling machine top horizontal roll left and right pair 19b1, 19b2 ... Web center position correction rolling machine Left and right of the lower horizontal roll of the machine 19c, 19d ... Left and right of the vertical roll of the web center position correction rolling mill 19c1, 19c2 ... Up and down of the left vertical roll of the web center position correction rolling mill 19d1, 19d2 ... Web center position correction rolling Vertical roll of the right vertical roll of the machine 19-1 ... Relief part of the horizontal roll of the web center position correction rolling mill 19-2 ... Vertical roll collar of the web center position correction rolling mill 19-3 ... Web center position correction rolling mill Horizontal roll circumference 19-4 ... Web center position correction Roller circumference 60, 61 ... Top and bottom of the horizontal roll of the finishing universal rolling mill 60a, 60b ... Top horizontal roll of the finishing universal rolling mill Left and right pairs 61a, 61b ... Left and right pairs of lower horizontal rolls of the finishing universal rolling mill 64, 65 ... Left and right pairs of vertical rolls of the finishing universal rolling mill L ... Production line M ... Material to be rolled

Claims (7)

A web center position correction rolling mill that corrects the thickness center of the web portion of the material to be rolled to the center width of the flange portion with respect to the material to be rolled, which is an intermediate material in the rolling process of H-section steel.
It has a vertically symmetrical horizontal roll pair and a symmetrical vertical roll pair.
The horizontal roll pair is provided with a relief portion in the vicinity of the flange tip corresponding portion on the side surface portion of the horizontal roll pair.
A web center position correction rolling mill characterized in that the vertical roll pair is provided with a flange for restraining a flange tip portion of a material to be rolled. The horizontal roll pair is configured by dividing both the upper roll and the lower roll into left and right pairs.
The web center position correction rolling mill according to claim 1, wherein the distance between the left and right pairs is freely changeable. The vertical roll pair is configured by dividing both the left roll and the right roll into upper and lower pairs.
The web center position correction rolling mill according to claim 1 or 2, wherein the distance between the upper and lower pairs is freely changeable. The web center position correction rolling mill according to any one of claims 1 to 3 is arranged in front of the finishing rolling mill.
The web is an intermediate material formed from a material through rough rolling, intermediate universal rolling, and edger rolling, or an intermediate material formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling. Center position correction A method for rolling H-shaped steel, which comprises correcting the center position of the web through a roll gap of a rolling mill and then performing universal finishing rolling to manufacture an H-shaped steel product. The web center position correction rolling mill according to claim 2 is arranged in front of the finishing rolling mill.
Regarding intermediate materials formed from raw materials through rough rolling, intermediate universal rolling, and edger rolling, or intermediate materials formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling.
The distance between the left and right pairs of the upper roll and the lower roll of the horizontal roll pair is adjusted according to the in-web dimension of the intermediate material, and the horizontal is corresponding to the thickness dimension of the web portion and the flange portion of the intermediate material. By adjusting the roll gap of the roll pair and the gap between the side surface portion of the horizontal roll pair and the circumferential portion of the vertical roll pair, the in-web method of the cross section of the intermediate material, the flange width, and the rolling reduction ratio of the flange thickness can be adjusted. Under the condition of 1% or less, the intermediate material is passed through the web center position correction rolling mill to correct the web center position, and then finish universal rolling is performed to manufacture an H-section steel product. Rolling method of shaped steel. The web center position correction rolling mill according to claim 3 is arranged in front of the finishing rolling mill.
Regarding intermediate materials formed from raw materials through rough rolling, intermediate universal rolling, and edger rolling, or intermediate materials formed by rough rolling, intermediate universal rolling, edger rolling, and in-web widening rolling.
The distance between the upper and lower pairs of the left roll and the right roll of the vertical roll pair is adjusted according to the flange width dimension of the cross section of the intermediate material, and the thickness dimension of the web portion and the flange portion of the intermediate material is adjusted. By adjusting the roll gap of the horizontal roll pair and the gap between the side surface portion of the horizontal roll pair and the circumferential portion of the vertical roll pair, the rolling ratio of the cross section of the intermediate material, the flange width and the flange thickness are reduced. The intermediate material is passed through the web center position correction rolling mill to correct the web center position under the condition that the amount is 1% or less, and then the finish universal rolling is performed to manufacture an H-shaped steel product. Rolling method of H-beam. The taper angle of the side surface portion of the horizontal roll pair that abuts on the inner side of the flange of the intermediate material and the taper angle of the circumferential portion of the vertical roll pair that abuts on the outer side of the flange of the intermediate material are determined by the intermediate material. The invention according to any one of claims 4 to 6, wherein the angle is set smaller than the flange inclination angle, and the web center position of the intermediate member is corrected while reducing the inclination angle of the flange portion of the intermediate member. Rolling method of H-section steel.

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