JP2007237275A - Method for manufacturing t-steel or angle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture T-steels and angles having proper shape without strain and twist. <P>SOLUTION: Notches N1, N2 which are opposed at approximately the same depth are formed on the upper and lower surfaces of the web 1a of a wide flange shape 1, with a pair of circular cutting edges 50, 51 which are concentrically attached to each of upper and lower horizontal rolls 10, 11 when the wide flange shape 1 is formed by hot-finish-rolling with a universal mill 30. After that, the residual stress of the wide flange shape 1 is reduced by cooling the wide flange shape 1 and applying roller straightening. After that, an uncut part s is cut by a circular cutting edge 80 which is arranged opposite to a cylindrical roller 60 into the notch N1 on the upper surface of the web 1a as supporting the lower surface of the web 1a of the wide flange shape 1 with the cylindrical roller 60. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a so-called cut T-shape obtained by cutting a web from a hot-rolled H-shaped steel (including an I-shaped steel similar to the H-shaped steel; hereinafter the same) or a grooved steel. In the process of manufacturing steel or cut angle steel (hereinafter simply referred to as T-shaped steel or angle-shaped steel), T-shaped steel or angle-shaped steel can be formed into an appropriately shaped T-shaped steel or angle-shaped steel, which deteriorates the transportability. The present invention relates to a method of manufacturing a T-shaped steel or an angle steel that can reduce the amount of bending of the steel, has a good cutting part, and has a small load on the cutting tool and can extend the life of the cutting tool.

  As a method for producing a T-shaped steel or an angle steel by forming a H-shaped steel or a grooved steel by rolling and cutting a web of the H-shaped steel or the grooved steel, Patent Document 1 (Japanese Patent Laid-Open No. 60-60 / 1990). The technology described in Japanese Patent No. 6202) is disclosed.

  According to the above technique, as shown in FIGS. 3 and 4 of Patent Document 1, a symmetrical cross-section steel is formed in an inverted W shape at the hot rolling stage, and the center of the inverted W shape steel is further formed. A V-notch groove is formed on the lower surface of the steel sheet, and after cooling, the corner portion of the web of the inverted W-shaped steel is crushed to cut the V-notch groove portion. Also, in this technique, a reverse W-shaped steel is sandwiched in a hole shape formed by a lower roll recessed in a V shape and an upper roll having a slit knife, and the V notch groove portion is finally cut. ing.

Japanese Patent Laid-Open No. 60-6202

  However, according to the technique described above, a V-notch groove is formed on the lower surface of the center of the inverted W-shaped steel in the hot rolling stage, and at that time, a large force acts on the central web from one side, and the web A large distortion or twist that is asymmetric in the vertical direction occurs. The distortion and twist at this time often have a great influence on the shape of the finally formed angle steel. As described above, with the above-described technology, it is difficult to stably manufacture an angle steel having an appropriate shape without distortion or twist.

  Further, in the above technique, when the inverted W-shaped steel is finally rolled down and cut, for example, as shown in FIG. 6, the lower surface 101 of the web 100a of the shaped steel 100 is lowered with a V-shaped lower roll 101. Since it receives, the cutting | disconnection part 100b of the web 100a hangs down, and the quality of angle irons falls remarkably.

  This invention is made in view of this point, and makes it the 1st objective to manufacture the T-shaped steel or the angle steel of the appropriate shape without a distortion and a twist using a comparatively simple installation. . It is a second object of the present invention to prevent dripping at the cut portion when cutting a T-shaped steel or an angle steel web.

  The present inventor considers that the cutting method using a cutting blade is the simplest and most efficient as a method of manufacturing a T-shaped steel or an angle steel by using H-shaped steel or groove-shaped steel as a raw material. , I studied how to solve the deterioration of quality caused by dripping or twisting of the cutting part, which is a disadvantage of cutting with a cutting blade. In addition, we considered a cutting method that extends the life of the cutting edge, makes the equipment less complicated, and does not generate chips.

  As a result, the cutting of the web is divided into two stages, and in the first stage, notches are formed in the web thickness direction by the convex cutting blades facing from both sides of the web with a low cutting resistance. Then, the residual stress is reduced or eliminated by roller straightening. Thereafter, in the second stage, it was found that a T-shaped steel or an angle steel with a small bend can be produced by cutting the uncut portion. In this case, it is not necessary to adopt special equipment or operation methods for curbing. In the second stage, with one side of the web to be cut supported, a cutting blade is inserted into the notch from the other side so as to face the other side, and there is no dripping of the cut part, and other than the uncut part Since almost no external force acts on this part, twisting can be prevented. In such a cutting method, the cutting blade is formed in a convex shape facing the both sides of the web, so that no chip is generated and even if the web plate thickness is large, most of the plate thickness is increased in the first stage. Cutting can be performed with heat with low deformation resistance, and in the second stage after cooling and roller correction, the cutting allowance (uncut portion) is a small amount, so the load on the cutting blade is small and the cutting blade life can be extended. From the above circumstances, the inventors have found basic knowledge and have reached the present invention. That is, the present invention is composed of the following.

  According to the present invention for achieving the objects of the first stage and the second stage, when the H-section steel or the groove-shaped steel is hot rolled by a rolling mill, the H-section steel or the groove-shaped steel is used. The notches facing each other are formed on the upper and lower surfaces of the web along the longitudinal direction of the web at substantially the same depth so that the uncut portions remain, and then the uncut portions are separated by cold to form two strips. A method for producing a T-shaped steel or an angle steel, characterized by producing a T-shaped steel or an angle steel, is provided.

  In order to achieve the purpose of the first stage, the above T-shaped steel or angle steel manufacturing method finish-rolls the H-shaped steel or groove-shaped steel with a rolling mill having a horizontal roll pair, and is concentric with the horizontal roll pair. The notch may be formed by a pair of circular cutting blades that are fixed in step S3 and have the same allowance for the circumferential surface of the horizontal roll pair.

  In addition, after the notch is formed, in order to achieve the purpose of the second stage, the H-shaped steel or the groove-shaped steel is cooled, the roller is straightened to reduce the residual stress, and then the uncut portion is separated. You may do it.

  Further, in order to achieve the object of the second stage, in the method for manufacturing the T-shaped steel or the angle steel, the one surface of the web is supported by the cylindrical roller or the flat plate, and the cylindrical roller or the flat plate is supported. You may make it isolate | separate the said uncut part by inserting the circular cutting blade arrange | positioned facing into the notch of the other surface of the said web, and cut | disconnecting the said uncut part.

  According to the present invention, when a T-shaped steel or a chevron steel is produced by cutting a web of an H-shaped steel or a channel steel, there is no sagging of the cut section of the T-shaped steel or the chevron, and no twisting of the T-shaped steel or the chevron. It was. In addition, the cutting load on the cutting edge is light, the cutting edge life can be extended, the cutting yield is high, and no special equipment or equipment for processing chips is required to improve the transportability.

  Hereinafter, preferred embodiments of a method for producing a T-shaped steel or an angle steel according to the present invention will be described. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  Drawing 1 is an explanatory view for explaining the manufacturing method of the T section steel concerning this embodiment. The manufacturing process of the T-shaped steel according to this embodiment is as follows. First, a finishing universal rolling mill composed of upper and lower horizontal roll pairs 10, 11 and left and right vertical roll pairs 20, 21 as shown in FIG. By 30, the H-section steel 1 is hot-finished and rolled. On the upper horizontal roll 10 and the lower horizontal roll 11, a pair of circular cutting blades 50 and 51 which are concentric with each other and have sharp points are fixed. Simultaneously with the finish forming and rolling, these upper and lower circular cutting blade pairs 50 and 51 bite into the upper and lower surfaces of the web 1a of the H-section steel 1, and notches (notches) N1 and N2 are formed on both upper and lower surfaces of the web 1a. It is formed.

  FIG. 2 is an enlarged cross-sectional view of the vicinity of the web 1a of the H-section steel 1 when the notches N1 and N2 are formed. When the notches N1 and N2 are formed, as shown in FIG. 2, the upper horizontal roll 10 and the lower horizontal roll 11 are in contact with the upper and lower surfaces of the web 1a, and the web 1a is restrained to stabilize the posture of the H-section steel 1. Let In this state, the circular cutting blade 50 fixed concentrically with the upper horizontal roll 10 forms a notch N1 on the upper surface of the web 1a, and at the same time, the circular cutting blade 51 fixed concentrically with the lower horizontal roll 11 , A notch N2 is formed on the lower surface of the web 1a. These notches N1 and N2 are formed along the longitudinal direction of the web 1a.

  At this time, the depth δ1 of the notch N1 by the circular cutting edge 50 is equal to the protrusion of the circular cutting edge 50 with respect to the circumferential surface of the upper horizontal roll 10, and the depth δ2 of the notch N2 by the circular cutting edge 51 is It becomes equal to the allowance of the circular cutting edge 51 with respect to the circumferential surface of the horizontal roll 11. The protrusion of the circular cutting edge 50 and the protrusion of the circular cutting edge 51 are set to be approximately equal, and the depth δ1 of the notch N1 and the depth δ2 of the notch N2 are substantially equal. This is because the vertical force acting on the web 1a is balanced by preventing the web 1a from being deformed by causing the pair of circular cutting blades 50 and 51 to bite into the web 1a almost simultaneously. Further, when the thickness of the web 1a is tw, the relation of tw> δ1 + δ2 is satisfied, and the web 1a is not completely separated at the formation stage of the notches N1 and N2, and the uncut portion s is left.

  In this example, the universal rolling mill 30 is used as a finishing mill so as to be able to cope with various plate thicknesses of the H-section steel 1. The horizontal roll pairs 10 and 11 are divided into left and right first rolls 10a and second rolls 10b, first rolls 11a and second rolls 11b, respectively. 1 uses a so-called trunk width variable horizontal roll that can cope with changes in various web inner methods w (shown in FIG. 1A). This body width variable horizontal roll is disclosed in, for example, Japanese Patent Laid-Open Nos. 7-39913, 7-80514, 7-80515, and 7-80516. However, the rolling mill used in the present invention is not limited to this type of rolling mill, and may be another rolling mill having a horizontal roll pair.

  After the notches N1 and N2 of the web 1a are formed by the universal rolling mill 30, the H-section steel 1 is then cooled, and the H-section steel 1 is bent and warped by the straightening by the roller straightener during the cold. Stress is reduced.

  Thereafter, as shown in FIG. 1B, the lower surface of the web 1 a of the H-section steel 1 is supported by the cylindrical roller 60, and the periphery of the notch N <b> 2 on the lower surface of the web 1 a is pressed by the cylindrical roller 60. Further, the entire H-section steel 1 is fixed by a pair of rollers 70 and 71 arranged on the left and right so as not to be displaced during cutting. In this state, as shown in FIG. 3, a circular cutting edge 80 disposed facing the cylindrical roller 60 is inserted into the notch N1 on the upper surface of the web 1a, and the uncut portion s is cut. The biting allowance δ3 of the circular cutting edge 80 at this time is set to be deeper than the depth δ1 of the notch N1, and is set to be shallower than the web plate thickness tw in order to avoid contact with the cylindrical roller 60. Yes. By cutting the uncut portion s of the web 1a, two T-shaped steels 2 as shown in FIG. 1B are formed.

  In this example, when the uncut portion s of the web 1a is cut, the lower surface of the web 1a is supported by the cylindrical roller 60. However, instead of the cylindrical roller 60, the web 1a may be supported by a flat plate. Good. Alternatively, the cylindrical roller 60 may support the upper surface of the web 1a and cut the uncut portion s with the circular cutting edge 80 from the lower surface side of the web 1a.

  According to the above embodiment, since the equivalent notches N1 and N2 are formed on the upper and lower surfaces of the web 1a of the H-section steel 1 during hot rolling, an asymmetrical force is generated when the notches N1 and N2 are formed. It does not act on the section steel 1, and when the H section steel 1 is finally cut, no dripping or twisting occurs at the cut portion of the H section steel 1. In addition, since the notches N1 and N2 are formed and the roller is cold-corrected to reduce bending and residual stress, and then the final cutting is performed, the bending of the T-shaped steel 2 after cutting is small. As a result, the T-section steel 2 is excellent in transportability, and the T-section steel 2 can be finally corrected with a press or the like and shipped. Further, since the bending of the T-section steel 2 during the manufacturing process can be suppressed, it is possible to relatively simplify the subsequent manufacturing equipment for the T-section steel 2.

  In addition, according to the present embodiment, since most of the web 1a in the thickness direction of the web 1a is cut hot, and the uncut portion s that is cut cold is relatively small, the circular cutting blade The load with respect to 50, 51, 80 is small, and the lifetime of these cutting blades 50, 51, 80 can be lengthened. Also, according to this cutting method, no chips are generated.

  In addition, since it is not necessary to form the shaped steel into a complicated inverted W shape as in the prior art, there is no need for a special and large rolling equipment, and the equipment cost can be reduced. Further, since the circular cutting edges 50 and 51 are cut down from both the upper and lower surfaces of the web 1a, the vertical position of the web 1a can be maintained near the center of the circular cutting edges 50 and 51. As a result, even if the thickness of the web 1a varies, the upper and lower notches N1, N2 and the uncut portion s can be stably formed.

  In the above embodiment, when the uncut portion s of the web 1a is cut, the lower surface side of the web 1a opposite to the circular cutting blade 80 is pressed by the cylindrical roller 60. The reaction force when inserted into the cutting part s can be received by the cylindrical roller 60. For this reason, the T-section steel 2 having a very good quality can be obtained without causing the drooping of the cut portion of the T-section steel as shown in FIG. 6 and the twisting of the T-section steel.

  Although the manufacturing method of the T-section steel 2 has been described in the above embodiment, the same applies to the case where the material to be cut is a groove-shaped steel and two angle irons are manufactured from the groove-shaped steel. For example, as shown in FIG. 4 (a), the grooved steel 3 is hot finish-rolled by the universal rolling mill 30, and at the same time, the circular cutting blades 50 and 51 are used to center the upper and lower surfaces of the web 3a of the grooved steel 3. Notches N1 and N2 are formed. After that, the channel steel 3 is cooled, and bending and warping are reduced by a straightening roll in the cold, and the residual stress is reduced. Thereafter, as shown in FIG. 4 (b), the lower surface side of the web 3a of the channel steel 3 is supported by the cylindrical roller 60, and in this state, the circular cutting edge 80 on the upper surface side of the web 3a is used to remove the web 3a. The cut portion s is cut, and the two angle steel 4 is manufactured.

  Even in this case, the final cut portion of the angle steel 4 does not sag and the angle steel 4 is not twisted, as in the method of manufacturing the T-shaped steel 2 described above. Further, the formed angle steel 4 has a small bend and is excellent in transportability. Furthermore, the load on the circular cutting edges 50, 51, 80 is small, and the life of these cutting edges 50, 51, 80 can be extended. Further, when the web 3a of the channel steel 3 is cut, the web surface on the opposite side of the circular cutting edge 80 is pressed by the cylindrical roller 60. This also causes the drooping of the cut portion of the angle steel 4 and the angle steel 4 Thus, the angle steel 4 having an extremely good quality can be obtained.

  The preferred embodiment of the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to such an example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the spirit described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  An embodiment is shown in FIG. The H-section steel 1 having a web height A = 600 mm, a web thickness tw = 9 mm, a flange width B = 200 mm, and a flange thickness tf = 12 mm is finish-formed and rolled by the universal rolling mill 30. Notches N1 and N2 having a depth δ1 = 3.5 mm, δ2 = 3.5 mm, and an uncut portion s = 2.0 mm were formed. Thereafter, bending stress was repeatedly applied to the H-section steel 1 by a roller straightening machine 90 having eight rollers to remove bending and residual stress. Thereafter, the cylindrical roller 60 installed immediately after the roller straightening machine 90 supports the lower surface of the web 1a of the H-section steel 1 while supporting the lower surface of the web with the circular cutting edge 80 disposed facing the cylindrical roller 60. A two-section T-section steel 2 was produced by cutting at the center of the width of 1a. Thereafter, the T-section 2 was finally corrected with a press to obtain a product of good quality. The biting allowance δ3 of the circular cutting edge 80 was 6.0 mm.

  The manufactured T-shaped steel 2 did not sag at the cut portion, and had some outward bending but no twist. Conveyance of the T-shaped steel 2 after cutting was good, and no special equipment for stabilizing the posture was required. Regarding the life of the cutting edge, for example, when the web is cut from one side with a single cutting edge as in the prior art, the total cutting length is about 8 km when cutting a 9 mm thick web, and the cutting edge is worn down to the cutting surface. Shape failure started to occur and the lifetime was almost exhausted, but in the present invention, a good cut shape could be maintained even after cutting about 20 km. Moreover, there was no generation of chips and the cutting yield was good.

  The present invention is useful when manufacturing a T-shaped steel or an angle steel having an appropriate shape without distortion or twisting.

(A) is a longitudinal cross-sectional view of H-section steel in a rolling mill which shows a mode that a notch is formed in the web of H-section steel. (B) is a longitudinal cross-sectional view of H-section steel which shows a mode that the web of H-section steel is cut | disconnected. It is an expanded sectional view of the cutting position vicinity of the web at the time of forming a notch in the web of H-section steel. It is an expanded sectional view of the cutting position vicinity of the web at the time of cut | disconnecting the web of H-section steel. (A) is a longitudinal cross-sectional view of the channel steel in the rolling mill which shows a mode that a notch is formed in the web of channel steel. (B) is a longitudinal cross-sectional view of the channel steel showing a state of cutting the web of channel steel. It is explanatory drawing explaining the Example which manufactures T-section steel from H-section steel based on this invention. It is explanatory drawing which shows the conventional web cutting part.

Explanation of symbols

1 H-section steel 1a Web 2 T-section steel 10, 11 Horizontal roll 50, 51 Circular cutting edge 60 Cylindrical roller 80 Circular cutting edge N1, N2 Notch s Uncut part

Claims (4)

When the H-shaped steel or channel steel is hot rolled by a rolling mill, notches facing each other are formed on the upper and lower surfaces of the H-shaped steel or channel steel so that uncut portions remain. T-shaped steel or chevron, characterized in that it is formed along the longitudinal direction of the web at an equal depth, and then the uncut portion is separated in the cold to produce two-strand T-shaped steel or angle steel Steel manufacturing method. The above H-shaped steel or grooved steel is finish-rolled by a rolling mill having a horizontal roll pair,
2. The T-section steel according to claim 1, wherein the notch is formed by a pair of circular cutting blades fixed concentrically to the horizontal roll pair and having substantially the same allowance relative to the circumferential surface of the horizontal roll pair. Or the manufacturing method of angle iron. 3. The method according to claim 1, wherein after the notch is formed, the H-shaped steel or the groove-shaped steel is cooled, subjected to roller correction to reduce residual stress, and then the uncut portion is separated. A method for producing the T-shaped steel or the angle steel described. While supporting one surface of the web with a cylindrical roller or flat plate, a circular cutting blade disposed opposite to the cylindrical roller or flat plate is inserted into the notch on the other surface of the web to insert the uncut portion. The method for producing a T-shaped steel or an angle steel according to any one of claims 1 to 3, wherein the uncut portion is separated by cutting.

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