JPH11285703A - Rolling method for H-section steel - Google Patents

Abstract

(57) [Summary] High-precision H with particularly excellent flange thickness uniformity
Manufactures shaped steel. A hot dimension meter 10 performs sampling measurement of a flange in a vertical direction when measuring a flange thickness.
The hot dimension meter calculation device 110 calculates the average value of the sampling data from the foot of the flange to immediately before the corner R of the fillet portion, and uses the average value as the measurement result of the flange thickness. Then, the dimensional control arithmetic unit 100 calculates the deviation between the measurement result and the target dimension to perform dimensional control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling an H-section steel, and more particularly to an improvement in dimensional accuracy of the H-section steel.

[0002]

2. Description of the Related Art FIGS. 5 (a), 5 (b), and 5 (c) are views showing the configuration of a hot manufacturing facility for an H-shaped rope. As shown in these figures, the H-shape hot manufacturing equipment includes a heating furnace 1, a breakdown rolling mill 2, a rough universal pressing machine 3,
3 ', a combination of edger rolling mills 4, 4' and finishing universal rolling mill 5.

FIGS. 6 (a), 6 (b) and 6 (c) are views showing the cross-sectional shapes of H-shaped steel blanks. In the above-described H-shape hot manufacturing equipment, the material such as the slab 51, the bloom 52, the beam blank 53, etc., as shown in these figures, is successively passed through and rolled to obtain a predetermined sectional dimension.
Shaped steel is manufactured.

FIGS. 7 (a) and 7 (b) are views showing the hole shape of the breakdown rolling mill 2 of the above-described H-shape hot manufacturing equipment. As shown in these figures, the breakdown rolling mill 2 is a double rolling mill in which upper and lower rolls each provided with a plurality of open die 54 or closed die 55 are arranged along a roll drum. Here, a rough shaped steel piece 8 having an H-shaped cross section (FIG. 1)
0) is rolled.

FIGS. 8 (a), 8 (b) and 8 (c) are views showing the transition of the cross-sectional shape of the material to be rolled after the rough universal rolling mill of the H-section steel hot manufacturing equipment. As shown in FIG. 8A, in the rough universal rolling mill 3 including the horizontal roll 56 and the vertical roll 57, the rolling of the rough shaped steel slab 8 obtained by the breakdown rolling is further advanced, and In the roll 56, the web is pressed down in the thickness direction, and the horizontal roll 56 and the vertical roll 57 press down the flange in the thickness direction. Then, as shown in FIG. 8B, the flange width is reduced to a predetermined size by the edger roll 58 of the edger rolling mill 4 used in combination with the rough universal rolling mill 3.

In the above rough rolling, the rough universal rolling mill 3 and the edger rolling mill 4 are used until the material to be rolled has a predetermined sectional size.
Is repeated a plurality of times in a group of rough universal rolling mills, and thereafter, as shown in FIG.

FIG. 9 is an explanatory diagram of the dimensions (tolerance) of the H-section steel. H-section steel 6 manufactured by the above-described rolling process
As shown in FIG. 9, the dimensional tolerances such as web thickness t1, four flange thicknesses t21, t22, t23, t24, left and right flange widths B1, B2, and deviation S of the center of the web are defined in FIG. It is important to roll these dimensions with good precision, and when manufacturing H-section steels that require such dimensional precision, if there is a dimensional deviation, the yield decreases and the rolling efficiency is impaired. .

In recent years, the demand for thin-walled H-section steels has been increasing, and from the viewpoint of reducing residual stress or preventing the occurrence of shape defects, a flange portion having a lower cooling rate than a web is hot-rolled. During the process, or after the end of the final stage, water cooling may be performed forcibly. At this time, if the flange thicknesses at the top, bottom, left and right are not uniform, the temperature of the steel material will be uneven,
There were disadvantages such as uneven cooling and shape defects, and it was difficult to perform stable rolling for the following reasons.

In the breakdown rolling mill 2, FIG.
(A), a plurality of hole types 54 and 55 as shown in (b).
However, due to the setting position of the centering guide of the material to be rolled, the rolling bite posture or hole shape, and improper pass schedule or backlash of the rolling mill, etc., the desired left and right vertical symmetry It is difficult to always obtain an appropriate crude steel slab, and a crude steel slab having a non-uniform cross-sectional shape causes a reduction in dimensional accuracy of a final product after the subsequent universal rolling.

[0010] In the rolling in the rough universal rolling mill group, various rolling factors affect the deformation of the web and the four flanges, and the deformations affect each other. It is difficult to make the thickness and the leg length uniform, that is, it is difficult to set the flange thickness deviation, the center deviation of the web, and the left and right flange width deviation to “0”.

Next, the reason why it is difficult to make the flange thickness uniform will be described with reference to FIGS.
FIG. 10 is an explanatory diagram showing the cross-sectional shape of the crude steel slab after the breakdown rolling, and FIG. 11 is an explanatory diagram showing the displacement of the coarse steel slab, the vertical roll, and the horizontal roll.

The first reason why it is difficult to make the flange thickness uniform is that when the sectional shape of the crude steel slab 8 after breakdown rolling is not symmetrical in the vertical and horizontal directions as shown in FIG. Is that the distance between the pair of horizontal rolls is made appropriate, and even if all four distances between the horizontal roll 56 and the vertical roll 57 are equally set properly and rolled, the flange of the rough steel piece 8 to be rolled is Since the thickness of each part corresponding to the above is different, the rolling reaction force at each of the four flanges is different. As shown in FIG. 11, if only the vertical roll 57 elastically supported by the difference in the rolling reaction force, However, since the horizontal roll 58 is also displaced in the roll axis direction, the thickness of each part of the flanges 45 and 46 after the universal rolling is not uniform.

[0013] The second reason is that even if the cross-sectional shape of the crude steel slab after the breakdown rolling is good and symmetrical in the vertical and horizontal directions, the horizontal roll pair and the vertical roll pair are preliminarily rolled before rolling in the universal rolling. It is extremely difficult to set the desired interval with high accuracy and confirm it at present because there is no play in the rolling mill or an effective roll interval detector, and if the roll interval of a certain pass is inappropriate, The material to be rolled becomes a rolled material having a non-uniform thickness with respect to the next pass and thereafter after the pass rolling, and as described above, this causes a reduction in dimensional accuracy of the final product.

Various studies have been made on the dimensional control of the flange thickness in the H-section steel rolling. JP-A-6-15327 discloses a technique for making the thickness of four flanges uniform.
9 dimensions required for H-shaped steel (web thickness, flange thickness 4 places, flange leg length 4 places)
There is a technique proposed in Japanese Patent Application Laid-Open No. 9-103814 (Japanese Patent Application No. 7-260384) as a technique for controlling all of the above-described methods. ) Can be expressed as in the following equations (1) to (4) (see the explanatory diagram of the gauge meter type in FIG. 4), and at a position close to the upstream side of the universal rolling mill during the course of coarse universal rolling. The dimensions of each of the four flange thicknesses and other parts of the H-section steel 9 are measured, and deviations from the respective target dimensions are calculated based on the measurement results. The position of each actuator (rolling roll, etc.) is calculated based on the calculation results. And a method of rolling an H-section steel rolled in one or more passes.

Tf1out = (PV1 + PV2) / MV + (PV1-PV3) / Mhs + SV1 + SF + (Sh / 2 + PL) * tan (θ) + (PV1-PV2) / MVD + offset2 ... (1) tf2out = (PV2 + PV1) / MV + ( PV2-PV4) / Mhs + SV1-SF + (Sh / 2-PL) * tan (.theta.) + (PV2-PV1) / MVD + offset3 ... (2) tf3out = (PV3 + PV4) / MV + (PV3-PV1) / Mhs + SV2 −SF + (Sh / 2 + PL) * tan (θ) + (PV3-PV4) / MVD + offset 4 (3) tf4out = (PV4 + PV3) / MV + (PV4-PV2) / Mhs + SV2 + SF + (Sh / 2 + PL) * tan (θ) ) + (PV4−PV3) / MVD + offset 5 (4)

Where, tf1out: upper flange thickness on the drive side after universal rolling of the corresponding pass tf2out: lower flange thickness on the drive side after universal rolling of the corresponding pass tf3out: upper flange thickness on the free side of the corresponding pass after universal rolling tf4out: applicable Thickness of the lower flange on the free side after universal rolling of the pass PVl: Rolling reaction force on the upper flange portion on the drive side of the corresponding pass PV2: Rolling reaction force on the lower flange portion of the drive side on the corresponding pass PV3: Rolling reaction force PV4: Rolling reaction force of the lower flange portion on the free side of the corresponding pass Sh: Horizontal roll opening PL: Horizontal roll pass line SV1: Drive vertical roll opening SV2: Free vertical roll opening SF: Horizontal roll shift θ: Vertical roll taper angle MV: Mill constant of vertical rolling Mbs: Horizontal roll taper angle Mill constant in thrust direction MVD: Mill constant for vertical load difference in vertical rolling

On the other hand, the H-section steel 9 in the course of rough universal rolling is used.
As a technique for measuring the flange thickness, Japanese Patent Application No. 8-29
There is a technique using a scanning type laser distance meter proposed in Japanese Patent No. 3226.

[0018]

By the way, in the H-shaped steel 6 as the final product, the definition of the four flange thicknesses t21, t22, t23 and t24 as shown in FIG. 9 is almost at the center of the leg length. A point (B
The thickness of the flange portion is determined by JIS and other standards.

According to the above-mentioned prior art, in order to make the thickness of the four flanges uniform, H during the rough universal rolling is used.
At least four flange thicknesses of the section steel 9 are measured (for example, using a scanning type laser distance meter disclosed in Japanese Patent Application No. 8-293226), and dimensional control is performed based on the measurement results.

However, the flange thickness of the H-section steel 9 in the course of the rough universal rolling is not uniform in the flange width direction, and the degree of unevenness is different between the upper, lower, left, and right sides.
Moreover, the actual situation is different for each rolling size and each rolling pass (see FIGS. 12A and 12B). The causes are the cross-sectional shape of the crude steel slab 8 after the breakdown rolling, the inclination caused by the backlash of the vertical roll 57 due to the rolling reaction force (see FIG. 13), and the bulging 60 by the edger rolling (FIG. 8B). It is presumed that mutual influences are formed in a complicated relationship. FIG. 13 is an explanatory view showing the inclination of the rolls. The solid line shows the state before rolling, and the wavy line shows the state during rolling.

Therefore, the flange thickness at the four locations of the H-section steel 9 in the course of rough universal rolling is determined by which position in the width direction is measured.
There was a possibility that the thickness was almost 10% different from the thickness of the point.

Further, the flange thickness at the point of B / 4 is accurately measured, and the B thickness of the H-section steel 9 in the course of rough universal rolling is measured at four places.
Even if the flange thickness at the / 4 point is controlled to be uniform, the distribution pattern of the thickness in the flange width direction is different between the top, bottom, left and right and each rolling pass, and is not an accurate representative flange thickness. The model formula does not match the actual rolling process (eg, the offset amount of the gauge meter formula is not stable, etc.), and the flange thickness at four B / 4 points of the H-section steel 9 in the course of rough universal rolling is completely uniform. It was difficult to control.

It is also assumed that H during rough universal rolling is
Even if the flange thickness at four B / 4 points of the shape steel 9 becomes uniform, the flange thicknesses t21 and t of the four portions of the H-shaped steel 6 of the final product having a substantially flat flange portion are provided.
22, t23 and t24 were not always uniform.

The present invention has been made in order to solve such a problem, and an H-shape steel which is capable of manufacturing a high-precision H-shape particularly excellent in flange thickness uniformity is provided. An object is to provide a rolling method.

[0025]

A method for rolling an H-section steel according to the present invention measures the dimensions of an H-section steel after forming and rolling, calculates a deviation from each target dimension based on the measurement result, and calculates the deviation. In the method of rolling an H-section steel by changing the position of each actuator based on the calculation result, in measuring the flange thickness, the flange is sampled in the vertical direction, and the flange is measured from the foot to a point immediately before the corner R of the fillet portion. The average value of the sampling data is obtained, the average value is used as the measurement result of the flange thickness, and the deviation from the target dimension is calculated to perform the dimension control.

For example, when a rough steel slab having an H-shaped cross section obtained by performing a breakdown rolling is subjected to a plurality of passes of hot rolling using a rough universal rolling mill and an edger rolling mill, a universal rolling mill is used. The flange thickness of the H-section steel after forming and rolling at four locations is measured at a position close to the upstream side (downstream when the universal rolling mill is downstream of the edger rolling mill). When measuring the flange thickness, the flange is sampled in the vertical direction, the average value of the sampling data from the foot to the corner R of the fillet portion is obtained, and the average value is used as the flange thickness measurement result. Dimension control is performed by calculating a deviation from the dimension and changing the position of each actuator (rolling roll or the like) according to the deviation.

In the present invention, the reason why the range of the measurement data for obtaining the flange thickness is limited from the foot of the flange to immediately before the corner R59 of the fillet portion (see FIG. 14) is that the range of the measurement data is limited. The shape of the horizontal roll 59 is determined by the shape of the horizontal roll, and when the vertical roll opening is changed (change in the rolling reduction of the flange portion), the change rate of the rolling reaction force of the corner R portion 59 is smaller than that of the other flange portions. That's why. FIG. 14 is an explanatory view of the measurement range of the flange thickness of the H-section steel during the course of the rough universal rolling. In the figure, the region marked with * indicates the measurement range of the flange thickness or the range of the data to be used. The solid line shows the shape of the H-section steel after the vertical roll is strongly reduced in the pass with the coarse universal, and the wavy line shows the shape of the H-section steel after the normal reduction of the vertical roll in the pass with the coarse universal. It is.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a configuration of a rolling facility to which an H-section steel rolling method according to an embodiment of the present invention is applied. This rolling equipment includes a heating furnace 1, a breakdown rolling mill 2, a rough universal rolling mill 3, an edger rolling mill 4, 4 ', a finishing universal rolling mill 5, a bite adjusting device 7, a hot dimension gauge 10, and a dimension control. It comprises an arithmetic unit 100 and a hot dimension meter arithmetic unit 110.

FIG. 2 is a front view of the hot dimension meter 10 of FIG. The hot dimension meter 10 includes a C-shaped frame 14 provided with wheels 12 and 13 that roll on rails 11. Elevating racks 16 and 17 are attached to the base and the front of the upper frame 15 of the C-shaped frame 14 so as to be able to move up and down. Each of the elevating pedestals 16 and 17 is provided with a laser distance meter 18 of a lightwave distance measuring type and a scanning type.
20, 21 to 23 are fixedly attached in a predetermined direction. In addition, spot-type laser distance meters 25 and 26 of a light-wave distance measuring type are provided above and below the passing line of the H-section steel 9. Further, below the laser distance meters 18 to 20, 21 to 23, scanning distance type laser distance meters 39, 40 which are of a light wave distance measuring type are arranged.

The H-shaped steel 9 is conveyed on a roller conveyor 41, and the lower frame 31 and the upper frame 15 of the C-shaped frame 14 are arranged at intermediate positions thereof so that the H-shaped steel 9 passes with a sufficient gap. I have. The control device 10a is mounted on the C-shaped frame 14, and the hot dimension meter 1
0 operation is controlled. In addition, the scanning type laser distance meter 18 (19 to 23, 39, 4
The same applies to 0), in which the laser beam to be irradiated is scanned, and the distance is measured based on the phase difference between the laser light applied to the measurement location and the laser light reflected from the measurement location.

FIG. 3 is an explanatory diagram showing a laser distance meter extracted from FIG. 2 and showing a relative position with respect to an H-section steel. As shown in FIG. 3, when the shape and thickness of the upper half of the flange 45 among the flanges 45 and 46 of the H-section steel 9 in the course of rough universal rolling are to be measured, the laser distance meter 21 The surface coordinates inside the upper half of the flange 45 are measured, and the surface coordinates outside the upper half of the flange 45 are measured by the laser distance meter 19. Similarly, when the shape and thickness of the lower half of the flange 45 are to be measured, the laser rangefinder 2 is used.
When using 0,40 and measuring the shape and thickness of the upper half of the flange 46, use the laser rangefinders 18,22.
When the shape and thickness of the lower half of the flange 46 are to be measured using the laser distance meters 39 and 23, the measurement is performed. When the thickness of the web 47 of the H-section steel 9 is to be measured, a spot-type light-wave distance-type laser distance meter 25, which is disposed above and below the H-section steel 9,
26 will be measured.

The hot dimension meter arithmetic unit 110 takes in measurement data of several hundred points of the flange thickness from the foot of the flange to the intersection with the web, measured as described above, and outputs the data of the corner R59 of the fillet portion. It is obtained by averaging after excluding the data. The average value is assumed to be 4 points of the representative flange thickness of one section, 1 point of web thickness, 2 points of flange width,
It is transmitted to the dimension control arithmetic unit 100 as hot-section dimension information of nine points along with two points of center deviation.

The arithmetic unit 100 for dimension control calculates the deviation from the target value of each dimension and the information on the hot cross-section dimensions from the hot dimension meter arithmetic unit 110, and calculates the deviation from the relational expression obtained in advance. The correction amount of each roll interval and biting position to be corrected and the dimensional change amount of the material to be rolled are calculated. The relational expression used in this calculation is as disclosed in Japanese Patent Application Laid-Open No. 9-103814. In particular, the relational expression relating to the flange thickness is obtained by the above-described expressions (1) to (4). Is used. Then, all roll positions are adjusted based on the result of adding the roll gap correction amount to the set roll gap value. By performing such a process at least once, the uniformity of the flange thickness of the four portions of the H-section steel 6 of the final product, the uniformity of the length of the flange legs of the four portions, that is, the center deviation of the web and the lateral flange width deviation occur. In addition, the absolute values of the web thickness, the flange thickness, and the flange width can be finished to desired dimensions. For this reason, even in a rolled material immediately after the start of rolling of a certain size, the desired dimensions do not deviate, and the reduction in yield due to the deviated dimensions can be eliminated, thereby improving the rolling efficiency.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Using the rolling equipment shown in FIG. 1, hot rolling of an H-section steel having a web height of 450 mm and a flange width of 300 mm was performed, and the present invention was applied and the present invention was not applied. Each dimension of the product in the prior art was investigated.

Table 1 shows the results of a survey on the web thickness, the flange thickness at four places, and the flange leg length at four places, in comparison with the case where the present invention is not applied (prior art). As is clear from Table 1, according to the present invention, it was confirmed that the uniformity of the flange thickness was remarkably improved without affecting the web thickness, the flange width, and the center deviation.

[0036]

[Table 1]

[0037]

As described above, according to the present invention, the flange is sampled in the vertical direction, the average value of the sampled data from the toe to immediately before the corner R of the fillet portion is obtained, and the average value is obtained. Since the dimensional control is performed by calculating the deviation from the target dimension based on the measurement result of the flange thickness, a high-precision H that is particularly excellent in the uniformity of the flange thickness.
The section steel can be rolled, and the yield can be improved and the rolling efficiency can be improved by preventing dimensional deviation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a rolling facility to which an H-beam rolling method according to an embodiment of the present invention is applied.

FIG. 2 is a front view of the hot dimension meter of FIG.

FIG. 3 is an explanatory diagram showing a laser distance meter extracted from FIG. 2 and showing a relative position to an H-beam.

FIG. 4 is an explanatory diagram of a gauge meter type.

FIG. 5 is a diagram showing a configuration of an H-shape hot manufacturing facility.

FIG. 6 is a view showing a cross-sectional shape of a material for an H-section steel.

FIG. 7 is a view showing a groove shape of a breakdown rolling mill.

8A and 8B are diagrams showing a change in the cross-sectional shape of the material to be rolled in the H-section steel hot manufacturing equipment, FIG. 8A is a diagram showing the cross-sectional shape of the material to be rolled in rough rolling, and FIG. FIG. 3C is a diagram illustrating a cross-sectional shape of a material to be rolled in edger rolling, and FIG. 4C is a diagram illustrating a cross-sectional shape of a material to be rolled in finish rolling.

FIG. 9 is an explanatory diagram of dimensions (tolerance) of an H-section steel.

FIG. 10 is an explanatory diagram showing a cross-sectional shape of a crude steel slab after breakdown rolling.

FIG. 11 is an explanatory diagram showing displacement of a coarse rope, a vertical roll, and a horizontal roll.

FIG. 12 is an example of a measurement result of a flashing thickness in the width direction of an H-section steel in the course of rough universal rolling.

FIG. 13 is an explanatory diagram showing the inclination of a vertical roll.

FIG. 14 is an explanatory diagram of a measurement range of a flange thickness of an H-section steel in the course of rough universal rolling.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 heating furnace 2 breakdown rolling mill 3 coarse universal rolling mill 4 edger rolling mill 5 finishing universal rolling mill 6 H-section steel (product) 7 bite adjusting device 8 coarse section 9 H-section steel in the course of coarse universal rolling 10 heat Distance dimension meter 18 to 23, 39, 40 Scanning type laser distance meter 25, 26 Spot type laser distance meter 45, 46 Flange 47 Web 59 Corner R section 60 Bulging 100 Calculator for dimension control 110 Calculator for hot dimension gauge 110

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tatsuro Udagawa 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd.

Claims (1)

[Claims] 1. A method for measuring the dimensions of an H-beam after shaping and rolling, calculating a deviation from each target dimension based on the measurement result, and changing the position of each actuator based on the calculation result. In the method of rolling, when measuring the flange thickness, the flange is sampled in the vertical direction, the average value of the sampling data from the toe to just before the corner R of the fillet portion is obtained, and the average value is calculated as the flange thickness. A method for rolling an H-section steel, wherein a dimension difference is controlled by calculating a deviation from a target dimension as a measurement result.