JP6743835B2 - Method for rolling shaped steel and method for adjusting leveling amount in rolling shaped steel - Google Patents

Description

The present invention relates to a method for rolling a shaped steel and a method for adjusting a leveling amount in rolling a shaped steel.

Shaped steel typified by a steel sheet pile usually has a predetermined step surface shape by rolling a plurality of hole dies called calibers on rolls of a plurality of rolling mills and rolling the material through the hole dies in order. Rolled into a product. Such a rolling method is also referred to as groove rolling.
In the case of groove rolling of shaped steel, it may be difficult to uniformly reduce the cross-section of the shaped steel perpendicular to the longitudinal direction in the left-right direction within the cross-section. If the reduction is not uniform in the left-right direction in the cross section, the material may bend to the left and right with respect to the longitudinal direction, so-called bending may occur. If the bending remains until the product stage, the product needs to be press-corrected in order to keep the bending amount within the tolerance, and the productivity of the shaped steel decreases. In addition, even in the middle of rolling, if the bending is too large, various defects may occur due to the bending, and misrolls that make it impossible to continue rolling occur, resulting in a significant loss of productivity. There's a problem.

As a method of preventing bending in the rolling of shaped steel, for example, in Patent Document 1, in hot rolling of a steel sheet pile of a roughly U shape, a technique of restraining the upper and lower surfaces of the web and the side surfaces of the flange with a guide and rolling. Is disclosed. Further, Patent Document 1 discloses a technique in which a hat-shaped steel sheet pile having an arm portion 32 is rolled while further restraining the upper and lower surfaces of the arm portion 32 with guides.
Further, in Patent Document 2, for asymmetrical steel, various prediction values are calculated by a rolling deformation prediction model based on various setting data regarding rolling conditions and each measurement data of rolling roll position and guide position, There is disclosed a rolling method in which the bending amount of the shaped steel is obtained from this predicted value, and when the bending amount exceeds the allowable range, the roll gap and the positions of the entrance side guide and the exit side guide are corrected.

Further, in Patent Document 3, at the time of rolling the steel sheet pile, a method of supplying a lubricant to a part of the shaped steel which is a roll or a material to be rolled, on the entrance side of the rolling mill, correction of the hole shape and each rolling pass. The method of adjusting the roll opening degree and the method of making the opening degree difference between the upper and lower rolls are disclosed.
Further, in Patent Document 4, by using the relational expression between the rigidity of the housing post and the roll gap difference obtained based on the mechanical deformation amount of the rolling mill at the time of rolling, the work side during rolling before each rolling pass, Determine the target value for the roll gap difference between the work side and the drive side, which is necessary to make the difference between the output side plate thicknesses on the drive side zero, and based on this roll gap difference target value, the work side and drive side of the rolling mill A method of setting and adjusting each roll gap is disclosed.

JP, 2009-119513, A JP, 2003-39107, A JP, 2003-49422, A Japanese Patent Laid-Open No. 05-169120

By the way, the technique disclosed in Patent Document 1 is intended to restrain the bending caused by rolling with a guide, and thus highly accurate guide setting accuracy is required. In addition, since the guide tries to restrain the bend, there is a problem that the guide causes a flaw in the material. Further, if the guide cannot restrain the bending, there is a problem that the material to be rolled is clogged with the guide.

The technique disclosed in Patent Document 2 requires a highly accurate rolling deformation prediction model, and requires a great deal of labor to construct a model and a system. In addition, even if the system is constructed, the effect of curving becomes insufficient if the system of the prediction model is insufficient.
The technique disclosed in Patent Document 3 discloses that the roll opening is adjusted and the both ends of the roll are opened differently in order to correct the bending. There is no disclosure about whether to adjust the roll opening.

The technique disclosed in Patent Document 4 predicts the amount of mechanical deformation of the rolling mill during rolling and guides the condition that the bending amount of the first rolling becomes 0, but it changes at each rolling timing. There is a problem that errors that occur due to roll cutting accuracy and rolling mill assembly accuracy cannot be corrected.
Therefore, the present invention has been made by paying attention to the above-mentioned problems, and in rolling a shaped steel, in a rolling method of a shaped steel and rolling of a shaped steel that can suppress the occurrence of bending easily and efficiently. It is intended to provide a method for adjusting the leveling amount.

According to one aspect of the present invention, there is provided a method for rolling a shaped steel, which comprises rolling a plurality of materials continuously by using a plurality of rolling mills and a plurality of hole dies, wherein the first rolling is performed in a first rolling pass. When rolling the material, the bending amount of the first material after rolling by the first rolling pass is measured, and the left and right representative positions of the first material before rolling by the first rolling pass are measured. In the first rolling pass, the thickness deviation after rolling indicating the deviation of the sheet thickness at the representative positions on the left and right after the rolling by the first rolling pass is calculated. By adjusting the leveling amount of the rolling mill corresponding to each rolling pass for at least one of the second rolling pass and the first rolling pass in which rolling is performed immediately before the rolling pass, the thickness deviation before rolling and At least one of the thickness deviations after the rolling is different from that of the first material, the second material is rolled in the second rolling pass and the first rolling pass, and the first rolling pass is performed. The bending amount of the second material after rolling is measured, the thickness deviation before the rolling and the thickness deviation after the rolling are obtained for the second material, and the bending amount in the first material, the rolling amount Using the thickness deviation before rolling and the thickness deviation after rolling, and the bending amount in the second material, the thickness deviation before rolling and the thickness deviation after rolling, the rolling in which the bending amount is within the standard The thickness deviation before rolling and the thickness deviation after rolling are obtained, and based on the thickness deviation before rolling, the thickness deviation after rolling and the bending amount in the first material and the second material, Before the rolling of the material rolled after the third rolling, the target thickness deviation before the rolling and the thickness deviation after the rolling are calculated in the material rolled after the third rolling in which the bending amount is within the standard. The leveling amount of the rolling mill used in at least one of the second rolling pass and the first rolling pass is adjusted so that the thickness deviation of the rolling mill and the thickness deviation of the rolling mill can be targeted. Thus, there is provided a method for rolling a shaped steel, which comprises rolling in the second rolling pass and the first rolling pass.

According to an aspect of the present invention, a method of adjusting the leveling amount in rolling of a shaped steel, when a plurality of materials are continuously rolled using a plurality of rolling mills and a plurality of hole die, When rolling the first material in the first rolling pass, the amount of bending of the first material after the rolling by the first rolling pass is measured, and the first material passes the first rolling pass. The thickness deviation before rolling indicating the deviation of the sheet thickness at the left and right representative positions before rolling is calculated, and the thickness deviation after rolling indicating the deviation of the sheet thickness at the left and right representative positions after rolling by the first rolling pass. For at least one of the second rolling pass and the first rolling pass in which rolling is performed immediately before the first rolling pass, by adjusting the leveling amount of the rolling mill corresponding to each rolling pass, At least one of the thickness deviation before the rolling and the thickness deviation after the rolling is different from the first material under the condition that the second material is rolled in the second rolling pass and the first rolling pass, The bending amount of the second material after the rolling by the first rolling pass is measured, the thickness deviation before the rolling and the thickness deviation after the rolling are obtained for the second material, and the first material is obtained. In the above-mentioned bending amount, the thickness deviation before the rolling and the thickness deviation after the rolling, and the bending amount in the second material, the thickness deviation before the rolling and the thickness deviation after the rolling, the bending amount. The thickness deviation before rolling and the thickness deviation after rolling, which are within the standard, are obtained, and the thickness deviation before rolling, the thickness deviation after rolling, and the bending in the first material and the second material are obtained. Based on the amount, the target thickness deviation before rolling and the target thickness deviation after rolling in the material rolled after the third rolling, in which the bending amount is within the standard, are calculated, and rolling is performed after the third rolling. Rolling used in at least one of the second rolling pass and the first rolling pass so that the thickness deviation of the material to be rolled before the rolling and the thickness deviation of the material after rolling become the target. A method for adjusting the leveling amount in the rolling of shaped steel, which comprises adjusting the leveling amount of a rolling mill. Will be provided.

According to one aspect of the present invention, there is provided a method for rolling a shaped steel capable of simply and efficiently suppressing the occurrence of bending when rolling the shaped steel, and a method for adjusting the leveling amount in rolling the shaped steel.

It is an explanatory view showing rolling equipment concerning one embodiment to the present invention. It is sectional drawing which shows the shape of a steel sheet pile, (A) is sectional drawing which shows a hat-shaped steel sheet pile, (B) is sectional drawing which shows a U-shaped steel sheet pile. It is a plane part which shows a finish rolling mill. It is a partial front view which shows the rolling roll of a finish rolling mill. It is a front view showing the state where the upper roll of the rolling roll was inclined with respect to the lower roll. It is a schematic diagram which shows the bending amount of a steel sheet pile. 7 is a graph showing the relationship between rolling reaction force P _R and Δ _R. It is explanatory drawing which shows the calculation method of the size of the space|gap of an upper roll and a lower roll. 6 is a graph showing a method of adjusting the leveling amount. 9 is a graph showing a modified example of the method of adjusting the leveling amount. It is a graph which shows the change of the amount of bending by difference of thickness deviation before and behind rolling. It is a graph which shows the thickness deviation before and behind rolling in an example. It is a graph which shows the thickness deviation before and behind rolling in a comparative example.

In the following detailed description, in order to provide a thorough understanding of the invention, embodiments of the invention are illustrated and numerous specific details are described. However, it will be apparent that one or more implementations may be practiced without the details of such specific details. Also, the drawings show well-known structures and devices in a schematic representation for the sake of brevity.

<Rolling method for shaped steel>
A rolling method for a shaped steel according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. In the rolling in the present embodiment, the steel sheet pile 3 is manufactured by rolling the material heated in the heating furnace in the rolling equipment 1 shown in FIG. In the present embodiment, the steel sheet pile 3 is a hat-shaped steel sheet pile having a hat-shaped cross-sectional shape orthogonal to the longitudinal direction shown in FIG. The hat-shaped steel sheet pile has a web 30 extending in the left-right direction at the center, flanges 31 extending obliquely from both ends of the web 30, arm portions 32 extending in the left-right direction from the flange 31, and joint portions connected to the arm portions 32. 33 and. The shaped steel in the present invention may be a U-shaped steel sheet pile having a web 30, a flange 31, and a joint portion 33, as shown in FIG. 2(B).

The rolling facility 1 includes a heating furnace 10, a rough rolling mill 11, an intermediate rolling mill 12, and a finish rolling mill 13. In such a rolling facility 1, after the slab or the like as the material to be rolled is heated in the heating furnace 10, the rough rolling mill (BD) 11, the intermediate rolling mill (SR) 12 and the finish rolling mill (SF) 13 are processed. The steel sheet pile having a predetermined shape is manufactured by sequentially rolling the steel sheet pile. At least one hole type (also referred to as “caliber”) is provided on the rolling rolls of the rough rolling machine 11, the intermediate rolling machine 12, and the finish rolling machine 13, and at least one hole type provided on each of these rolling machines is provided. The material to be rolled is rolled by passing it once. The number of times the material to be rolled passes through each rolling mill for rolling is called a pass. Further, rolling by the rough rolling mill 11 is called rough rolling, rolling by the intermediate rolling mill 12 is called intermediate rolling, and rolling by the finish rolling mill 13 is called finish rolling.

In the present embodiment, in the finish rolling by the finish rolling mill 13, the section steel is rolled using the rolling method described below. As shown in FIG. 3, the finish rolling mill 13 includes a rolling roll 130, a pair of rolling down devices 131, two pairs of side guides 132A and 132B, a plate thickness measuring instrument 133, a bending gauge 134, and a computing device 135. Have and. Further, around the finish rolling mill 13, a plurality of transport rolls 14 arranged in the transport direction of the material 2 (the left-right direction in FIG. 3) with the rolling roll 130 interposed therebetween are provided.

As shown in FIG. 4, the rolling roll 130 includes an upper roll 130A and a lower roll 130B arranged side by side in the vertical direction (vertical direction in FIG. 4). Further, two kinds of hole types are provided side by side in the longitudinal direction of the rolling rolls 130 (the left-right direction in FIG. 4). The left hole type in FIG. 4 is referred to as K1 caliber, and the right hole type is referred to as K2 caliber. In the rolling roll 130, the final thickness reduction of the material 2 is performed by rolling with the K2 caliber before the final rolling, and then the joint portion 33 is bent and formed by rolling with the K1 caliber as the final rolling. The steel sheet pile 3 is manufactured. In the rolling with the K2 caliber, the material 2 finally passes through the K2 caliber while moving from the left side to the right side in the left-right direction of FIG. 3, and the rolling under the thickness reduction is completed.

The pair of reduction devices 131 are provided on both ends of the upper roll 130A in the longitudinal direction (vertical direction in FIG. 3) and support the upper roll 130A. Further, the pair of rolling down devices 131 has a lifting mechanism such as a cylinder, and adjusts the vertical height of the upper roll 130A, that is, the gap between the upper roll 130A and the lower roll 130B. The lifting operation of the pair of rolling down devices 131 is performed based on a command output from the computing device 135. Further, the pair of rolling down devices 131 are individually controlled, and as shown in FIG. 5, can be controlled even when the axis of the upper roll 130A is inclined with respect to the horizontal direction. Although not shown, also in the intermediate rolling mill 12, as in the finish rolling mill 13, rolling can be performed with the upper roll inclined with respect to the lower roll.

The two pairs of side guides 132A and 132B guide the material 2 into the hole shape of the rolling roll 130. The pair of side guides 132A are provided on the upstream side of the rolling roll 130 so as to face each other so as to sandwich the passing material 2 in the width direction (vertical direction in FIG. 3). The pair of side guides 132</b>B are provided on the downstream side of the rolling roll 130 so as to face each other so as to sandwich the passing material 2 in the width direction. In the present embodiment, the material 2 is assumed to move from the right side to the left side in the left-right direction of FIG. 3, and the left side of FIG. 3 is the upstream side and the right side is the downstream side.

The plate thickness measuring device 133 is a device that measures the plate thickness of the arm portions 32 on both sides of the material 2 before rolling, which has a cross-sectional shape close to the final shape of FIG. As the plate thickness measuring device 133, a γ-ray plate thickness gauge arranged above both the arm portions 32 of the material 2 can be used. In addition to this, as the plate thickness measuring device 133, a distance meter arranged above and below both the arm portions 32 of the material 2 can be used. Further, the plate thickness measuring device 133 is arranged on the upstream side of the rolling roll 130, continuously measures the plate thickness of both the arm portions 32 of the steel material S to be conveyed in the longitudinal direction, and the measured plate thickness is averaged. The thickness data is transmitted to the arithmetic unit 135.

The bend meter 134 is a device that measures the bend shape of the material 2 after finish rolling. The bending in the steel sheet pile 3 refers to a state in which the steel sheet pile 3 is deformed in the left-right direction (the protruding direction of the joint portion 33) with respect to the longitudinal direction, as shown in FIG. Further, the bending amount δ is defined as the maximum deviation from the reference straight line connecting both ends in the longitudinal direction of the joint portion between the web 30 of the steel sheet pile 3 and the flange 31. Further, in the case of simply measuring the bending amount δ, the bending amount in a predetermined length shorter than the length of the entire length of the steel sheet pile 3 in the longitudinal direction is measured, and the bending amount in the entire length of the steel sheet pile 3 is measured from this bending amount. The quantity δ may be calculated. The bending meter 134 measures the bending amount δ of the rolled steel sheet pile 3 and transmits the measurement result to the arithmetic unit 135. The bend gauges 134 are, for example, three or more laser rangefinders that are arranged at the same height in line in the transport direction of the material 2. The bending amount 134 measures the bending amount in the installation interval of three or more laser rangefinders, and further calculates the bending amount δ in the entire length of the steel sheet pile 3 from the bending amount and the total length of the steel sheet pile 3. Further, the bending meter 134 transmits the measurement result of the bending amount δ as rolling performance data to the arithmetic device 135.

Based on the thickness data acquired from the plate thickness measuring instrument 133 and the rolling performance data acquired from the bending gauge 134, the arithmetic unit 135 performs the reduction of the material 2 to be rolled next by the rolling roll 130, by the method described later. A set amount is calculated, and the rolling roll 130 is controlled so that the calculated reduction set amount is obtained. Further, the arithmetic device 135 can also adjust the reduction setting amount in the intermediate rolling mill 12.

A method for calculating the set reduction amount by the computing device 135 and a method for rolling the steel sheet pile 3 by the rolling facility 1 will be described in detail. In the present embodiment, the plurality of materials 2 to be rolled are continuously sent to the finish rolling mill 13 and finish rolled in order.
First, the material 2 to be rolled first is rolled with a K2 caliber (S100). At this time, before rolling, the plate thickness measuring device 133 measures the plate thickness of the left and right arm portions 32, and after rolling, the bending amount 134 measures the bending amount δ. In the first rolling, the rolling reduction amount of the rolling roll 130 is preferably set such that the central axis of the upper roll 130A is not inclined with respect to the lower roll, that is, the state is parallel to the horizontal direction. It may be performed in a state where the central axis of is inclined to some extent with respect to the lower roll.

Next, the computing device 135 acquires the thickness data and the rolling performance data for the first rolled material 2, and calculates the reduction setting amount of the rolling roll 130 for the second rolled material 2. Yes (S102). At this time, the arithmetic unit 135 first calculates the thickness deviation d _t before and after rolling. The thickness deviation d _t is a value calculated by the following equation (1) using the left and right thicknesses of the arm 32. In the formula (1), t _L is the thickness (mm) of the arm 32 on the left side (left side in FIG. 2) of the material 2, and t _R is the arm 32 on the right side (right side in FIG. 2) of the material 2. Is the thickness (mm).
d _t =ln(t _L /t _R )... (1)

The thickness deviation d _t before rolling can be calculated from the thickness data acquired from the plate thickness measuring device 133. Further, the thickness deviation d _t after rolling can be calculated and obtained from the roll position of the rolling roll 130 and the actual result of the rolling load. In the case of rolling by the K2 caliber, the deformation amount Δ _R at the right side reduction shaft position can be calculated from the rolling reaction force P _{R applied} to the right side reduction screw (screw). This can be calculated using the following equation (2). Note that in (2), K _R is a mill stiffness coefficient of the right side, as shown in FIG. 7, the relationship between the deformation amount delta _R with pressure axis position of the right reduction shaft rolling reaction force P _R and the right Is the slope of the straight line portion of the graph. FIG. 7 shows the relationship between the rolling reaction force and the amount of deformation. At low loads, it becomes non-linear due to the influence of the gap between the roll and chock and between the chock and housing, and each gap decreases as the load increases, and approaches a linear shape. E _R is a coefficient indicating a nonlinear deformation amount under low load, as shown in FIG. 7, intersects the graph extending the linear portion of the graph obtained from the relationship between the deformation amount delta _R with the rolling reaction force P _R It is the value on the horizontal axis. Further, the amount of deformation Δ _L at the left rolling shaft position of the rolling roll 130 can also be calculated in the same manner as the right side.
Δ _R =P _R /K _R +E _R (2)

Further, when obtaining the thickness deviation d _t after rolling, the roll position, that is, the gap between the upper roll 130A and the lower roll 130B in the left and right arm portions 32 of the material 2 is obtained. Since the roll diameter of the rolling roll 130 for rolling the shaped steel changes in the axial direction, it is necessary to consider the flexural deformation in consideration of this. Specifically, as shown in FIG. 8, the gap can be obtained by adding the reference gap, the leveling amount, the amount of deformation at the axial compression position, the amount of deflection, and the amount of flat deformation of the roll. it can. The reference gap indicates the size of the gap between the upper roll 130A and the lower roll 130B when the upper roll 130A is arranged so that the central axis is parallel to the lower roll 130B. The leveling amount indicates the amount of change in the size of the void due to the tilt when the upper roll 130A is tilted with respect to the lower roll 130B. The amount of deformation at the axial reduction position indicates the amount of change in the reduction axial position caused by the left and right rolling reaction forces. The amount of deflection is the amount of deflection obtained from the deflection shape of the roll shaft center, which is calculated by using Castiliano's theorem, assuming that a concentrated load is applied to several representative points of the K2 caliber during rolling. The flat deformation amount of the roll can be calculated using the Foppl equation.

The thickness deviation d _t after rolling can be calculated from the gap thus calculated for each roll axis direction.
After calculating the thickness deviation d _t before and after rolling, the computing device 135 determines whether the thickness deviation d _t before finish rolling of the second material 2 is positive or negative from the thickness deviation d _t before the first rolling. The rolling reduction amount in the intermediate rolling mill 12 is changed so as to be reversed, and the intermediate rolling is performed (S104). At this time, in the intermediate rolling mill 12, the inclination of the central axis of the upper roll with respect to the central axis of the lower roll is adjusted so that the amount of reduction of the left and right arm portions 32 of the material 2 is changed. The leveling amount, which is the amount of this inclination, can be appropriately set within a range in which the thickness of the steel sheet pile 3 after rolling does not cause a quality problem.

After step S104, finish rolling is performed such that the thickness deviation d _t of the second material 2 after the finish rolling with the K2 caliber is opposite to that of the first deviation from the thickness deviation d _t after the first rolling. The reduction amount set by the machine 13 is changed, and finish rolling is performed by the K2 caliber (S106). At this time, the computing device 135 changes the leveling amount of the rolling roll 130 and determines the reduction setting amount so that the thickness deviation d _t after finish rolling with the K2 caliber is opposite in sign to the first. That is, in the step S106, and the first run, the thickness deviation d _t after rolling thickness before deviation d _t and rolling, rolling is performed finish under conditions positive and negative respectively reversed. In step S106, similarly to the first measurement, the plate thickness measuring device 133 measures the plate thickness of the left and right arm portions 32 and the bend meter 134 measures the bending amount δ.

Further, the arithmetic device 135 acquires the thickness data and the rolling performance data for the material 2 rolled for the second rolling, and calculates the reduction setting amount of the rolling roll 130 for the material 2 rolled for the next third rolling. (S108). At this time, the arithmetic device 135 first calculates the thickness deviation d _t of the second material 2 before and after rolling, as in the first material.
Then, the arithmetic unit 135, the first run of the thickness deviation d _t and the amount of bend of the before and after rolling [delta], as well as from the thickness deviation d _t and curve amount [delta] of the rolling before and after the two eyes, the condition curve amount [delta] becomes 0 Determine the reduction setting amount. The thickness deviation before rolling on the horizontal axis d _t, is plotted thickness deviation d _t after rolling on the vertical axis, the first run and two second result of the material 2 is as shown in the graph of FIG. In step S108, a straight line connecting the first plot and the second plot is obtained for this graph, and the third material 2 on this straight line is calculated from the weighted average of the bending amounts of the first and second plots. The thickness deviation d _t between before and after rolling is determined. Specifically, it is as follows.
A straight line passing through the first and second plots in FIG. 9 is given by the following equation (3), where the horizontal axis is the x-axis and the vertical axis is the y-axis. In the formula (3), t _n ′ is the thickness deviation of the nth roll before rolling, and t _n is the thickness deviation of the nth roll after rolling.

Further, in this straight line, the value of the thickness deviation dt before and after rolling in the third material 2 obtained from the weighted average of the bending amounts between the two plots, that is, the coordinates in FIG. can get. In the equation (4), a is the first bending amount δ, and b is the second bending amount δ. This bending amount is shown by dividing the right bending and the left bending into positive and negative. For example, the right turn may be a positive value and the left turn may be a negative value.

Then, the arithmetic unit 135 determines the reduction setting amounts in the intermediate rolling mill 12 and the finish rolling mill 13 so that the condition of the target 1 plot in FIG. At this time, the thickness deviation d _t after rolling is obtained by changing the leveling amount and obtaining the thickness of the left and right arm portions 32 after rolling from the position of the rolling roll, as in the method described in step S102. You can That is, in step S108, the target value of the thickness deviation _dt before and after the finish rolling is obtained, and the leveling amounts of the intermediate rolling mill 12 and the finish rolling mill 13 that are the target values are determined.

After step S108, intermediate rolling in the intermediate rolling mill 12 and finish rolling in the finishing rolling mill 13 are performed on the material to be rolled third by the determined reduction set amount (S110). Further, the material 2 rolled after the fourth rolling is also rolled at the same set reduction amount as the third rolling. Regarding the material 2 rolled after the fourth rolling, bending may newly occur as the rolling progresses. This is because the wear and thermal expansion of the roll progresses or the surface condition of the roll changes as the rolling progresses. For this reason, when a bend that exceeds the standard is generated, the rolling in which the bend has occurred may be treated in the same manner as the above-described first rolling, and the same processing as in step S104 and subsequent steps may be performed. This makes it possible to prevent the subsequent bending.

<Modification>
Although the present invention has been described above with reference to particular embodiments, it is not intended to limit the invention by these descriptions. Other embodiments of the invention, including various modifications to the disclosed embodiments, will be apparent to persons skilled in the art upon reference to the description of the invention. Therefore, it should be understood that the embodiments of the invention described in the claims include the embodiments including these modifications described alone or in combination.

For example, in the above embodiment, the bending amount δ is the bending amount in the entire length of the material 2, but the present invention is not limited to this example. For example, a reference length in the longitudinal direction of the material 2 may be set, and the bending amount δ may be used to control the bending amount in this reference length. When the steel sheet pile 3 is rolled, bending tends to occur on the tip side. Therefore, for example, the reference length may be set to about 10 m, the bending amount δ in the section from the tip of the material 2 to the reference length may be measured, and this bending amount δ may be the control target. This makes it possible to effectively suppress the occurrence of bending even when the bending occurs only on the tip side and the amount of bending is small over the entire length.

Further, in the above embodiment, the thickness deviation _dt before and after the finish rolling of the material 2 to be rolled third is set in step S108 so as to obtain the target plot in FIG. 9, but the present invention is applicable. It is not limited to the example. For example, as shown in FIG. 10, the thickness deviation d _t of the material 2 to be rolled at the third or subsequent times may be set to be a plot of the target 2 or the target 3. The plot shown as the target 2 is a plot in which the thickness deviation d _t after rolling on the vertical axis is 0 in the straight line 1 passing through the target 1 which is the target calculated in step S108 of the above embodiment. The straight line 1 is a straight line inclined 45 degrees counterclockwise with respect to the horizontal axis, that is, a straight line having a slope of 1:1 between the amount of change in thickness deviation before rolling and the amount of change in thickness deviation after rolling. Further, the target 3 is a plot on the straight line 1 in which the value of the thickness deviation _dt before rolling on the horizontal axis is the same as the first plot. Here, the inventors performed finish rolling of the material 2 while changing the thickness deviation d _t before and after rolling, and investigated the bending amount δ under each condition. As shown in FIG. 11, as a result of the investigation, as the thickness deviation d _t before rolling increases, the thickness deviation d _t after rolling increases, so that the magnitude of the bending amount δ becomes approximately the same. Was confirmed. At this time, in order for the amount of bending δ to be about the same, it is necessary to change the plot of the thickness deviation d _t with an inclination of about 45 degrees in the graph of FIG. In other words, in the plot on the straight line 1 in the graph of FIG. 10, the bending amount can be made approximately the same as the target 1 regardless of the difference in the thickness deviation d _t . Further, in the case of target 2, since the thickness deviation d _t after rolling becomes 0, it becomes possible to manufacture the steel sheet pile 3 having excellent quality with respect to the thickness tolerance of the arm portion 32. Further, when target 3 is set, the thickness deviation d _t before rolling becomes the same as that of the first rolling, and there is no need to recalculate the reduction set amount in the intermediate rolling mill 12 in the rolling of the third rolling and thereafter, and rolling is simpler. It can be performed. Further, when target 3 is set, the plot may be on the straight line l and the value of the thickness deviation _dt before rolling on the horizontal axis, not on the first axis, is the same as the plot on the second axis. In this case as well, rolling can be performed easily as in the first rolling. It should be noted that which of the values of the first and second thickness deviations d _t is to be used is preferably such that the vertical axis of the obtained coordinates of the target 3 is close to zero. The straight line 1 does not necessarily pass through the origin of the coordinate system shown in FIG. This is because in rolling with a complicated cross-sectional shape such as a steel sheet pile, a right and left reduction ratio difference of 0 is not always established as a condition for straight rolling. This is also due to the fact that there is an error in the initially set roll inclination (0 pitch) and roll cutting for each rolling opportunity. Further, this is also due to the fact that the roll wear and thermal expansion progress as the rolling progresses, and the surface condition of the roll also changes. That is, according to the present invention, it becomes possible to control the bending in response to such an error in the initial setting and a change with time.

Further, in the above embodiment, the thickness deviation d _t after rolling is estimated, but the present invention is not limited to this example. For example, the plate thickness of the left and right arm portions 32 of the material 2 may be measured after rolling with the K2 caliber. In this case, the plate thickness may be measured using a plate thickness measuring device similar to the plate thickness measuring device 133 provided on the downstream side of the rolling roll 130, and the material 2 is fed back to the upstream side after rolling. The plate thickness measuring device 133 may measure the plate thickness.

Further, in the above-described embodiment, the rolling amount at the K2 caliber is configured to suppress the bending amount, but the present invention is not limited to such an example. For example, the same applies to the case of rolling with another rolling mill or another caliber, such as the caliber of the intermediate rolling mill 12. Even in the case of intermediate rolling, if the bending occurs, there is a possibility that the equipment 2 may be damaged due to the contact of the material 2 or the material 2 cannot be inserted into the die of the rolling mill. In such a case as well, by adjusting the leveling amount as in the above-described embodiment, it is possible to prevent the occurrence of bending and the problems associated therewith. In consideration of the time and effort required to change the leveling amount of the rolling mill, it is preferable to adjust the leveling amount not for rolling between different calibers of the same rolling mill but for rolling between different rolling mills.

Furthermore, in the above-described embodiment, the leveling amount is adjusted by using the plate thickness of the left and right arm portions 32 of the steel sheet pile 3, but the present invention is not limited to this example. In order to prevent bending in the left-right direction, the plate thickness used may be a left-right representative value, and may be something other than the arm portion 32. At this time, it is preferable that the left and right representative values are as far apart as possible. For example, in the case of a U-shaped steel sheet pile as shown in FIG. 2(B), the thickness may be the left and right ends of the flange 31 or the bottom of the joint portion 33 that is a horizontal portion of the joint portion 33.

Furthermore, in the above-described embodiment, in the rolling of the second material 2, the thickness deviation before and after the rolling is reversed from the positive and negative of that of the first material, but the present invention is not limited to this example. In the rolling of the second material 2, if the thickness deviation of at least one before and after rolling is different from that of the first material, the target third thickness deviation can be obtained by the same idea as in the above embodiment. .. In this case, even if the first and the second bends occur in the same direction, the target 1 can be obtained by obtaining the thickness deviation at which the bend amount becomes 0 from the weighted average.

Further, in the above-described embodiment, the thickness deviation d _t before and after rolling at which the amount of bending becomes 0 is determined in step 108, but the present invention is not limited to this example. It is sufficient that the bending amount is within the quality standard, and it is not necessarily 0.
Furthermore, although the steel sheet pile 3 is the steel sheet pile having the joint portion 33 in the above-described embodiment, the present invention is not limited to the example. The steel sheet pile 3 is not limited to the steel sheet pile 3 and may be a sectional steel having another cross-sectional shape as long as bending may occur due to a difference in thickness in the left-right direction in a cross section orthogonal to the longitudinal direction.

<Effects of the embodiment>
(1) A method for rolling a shaped steel (for example, a steel sheet pile 3) according to an aspect of the present invention uses a plurality of rolling mills (for example, an intermediate rolling mill 12 and a finish rolling mill 13) and a plurality of hole dies, A method of rolling a shaped steel, which comprises continuously rolling a plurality of materials 2, wherein the first material 2 is rolled in a first rolling pass (for example, finishing rolling by a K2 caliber of a finishing rolling mill 13). Then, the bending amount δ of the first material 2 after the rolling by the first rolling pass is measured, and the deviation of the plate thickness at the representative left and right positions before the rolling by the first rolling pass is measured for the first material 2. The thickness deviation before rolling is obtained, the thickness deviation d _t after rolling showing the deviation of the plate thickness at the left and right representative positions after rolling by the first rolling pass is determined, and rolling is performed immediately before the first rolling pass. Adjusting the leveling amount of the rolling mill corresponding to each rolling pass for at least one of the second rolling pass (for example, the intermediate rolling by the intermediate rolling mill 12 performed immediately before the finish rolling) and the first rolling pass. in at least one of pre-rolling thickness deviation d _t and the thickness deviation d _t after rolling, in the first run of the material 2, different, connect a second material 2 in the second rolling pass and the first rolling pass rolling, bending amount of the material 2 of the two eyes after rolling by the first rolling pass is measured, the two first material 2, determine the thickness deviation d _t after rolling thickness before deviation d _t and rolling, 1 bending amount in the material 2 of the present th [delta], the pre-rolling thickness deviation d _t and after rolling thickness deviation d _t, and the bending amount of the two second material 2 [delta], the thickness deviation of the pre-rolling d _t and the thickness deviation d after rolling with _t, curve amount thickness deviation before rolling δ is within the reference d _t and after rolling thickness deviation d _{t (e.g.,} the target value in FIG. 9) seeking, first run material and two second materials 2 in, on the basis of the δ curve amount and thickness deviation d _t after rolling the thickness deviation d _t before rolling, and the amount of flexure δ is a reference, before rolling a target in the material 2 to be rolled on or after 3 knots thickness deviation calculating a d _t and the thickness deviation d _t after rolling, so that the thickness deviation d _t after rolling thickness before deviation d _t and rolling of the material 2 to be rolled on or after 3 knots is assumed that the target First, the leveling amount of the rolling mill used in at least one of the second rolling pass and the first rolling pass is adjusted, and rolling is performed in the second rolling pass and the first rolling pass.

According to the configuration of the above (1), the leveling amount of the shaped steel rolled after the third rolling is adjusted based on the current state of the rolling mill, so that the bending amount can be reliably within the standard. it can. At this time, the bending amount can be appropriately controlled by considering the bending amount δ from the relationship with the thickness deviation d _t before and after rolling. Moreover, since it is only necessary to adjust the leveling amount, it is possible to more easily suppress the occurrence of bending.

(2) In the above configuration (1), when calculating the thickness before rolling to target deviation d _t and the thickness deviation d _t after rolling in the material 2 to be rolled on or after 3 knots, before rolling thickness deviation the d _t x, the thickness deviation d _t after rolling as y, the thickness deviation before rolling the bending amount δ is within the reference d _t and the thickness deviation d _t after rolling, is calculated using equation (4) ..
(3) In the configuration (2), when calculating the thickness before rolling to target deviation d _t and the thickness deviation d _t after rolling in the material 2 to be rolled on or after 3 knots, before rolling thickness deviation In the coordinate system where d _t is the horizontal axis and thickness deviation d _t after rolling is the vertical axis, the amount of change in thickness deviation before rolling and the amount of change in thickness deviation after rolling pass through the coordinates obtained from equation (4). Doo is 1: 1 and obtains a straight line l of the gradient consisting numerical values of the coordinates on the straight line l that was determined, curve amount is the thickness deviation before rolling to be within the reference d _t and the thickness deviation d _t after rolling.
According to the above configurations (2) and (3), the amount of bending can be kept within the reference, and further, the difference in plate thickness between the left and right representative positions before and after rolling can be adjusted.

(4) In the above configuration (3), when calculating the thickness before rolling to target deviation d _t and after rolling thickness deviation d _t in the material 2 to be rolled on or after 3 knots, on the straight line l and, the numerical value of the coordinates of thickness deviation d _t after rolling becomes 0, and the thickness deviation before rolling the bending amount δ is within the reference d _t and the thickness deviation d _t after rolling.
According to the configuration of (4), the bending amount can be set within the reference, and further, the difference between the plate thicknesses at the left and right representative positions after rolling can be zero.

(5) In the above configuration (3), when calculating the thickness before rolling to target deviation d _t and the thickness deviation d _t after rolling in the material 2 to be rolled on or after 3 knots, on the straight line l and, the numerical value of the first run or two second rolling thickness before deviation d _t and the same become coordinates, the thickness deviation before rolling the bending amount δ is within the reference d _t and the thickness deviation d _t after rolling.
According to the above configuration (5), the amount of bending can be kept within the reference, and further, the leveling amount in the second rolling pass does not have to be newly considered, so rolling can be performed more easily. You can

(6) In any one of the configurations (1) to (5), the thickness deviation before rolling and the thickness deviation after rolling _dt are ratios of plate thicknesses at representative left and right positions of the material before rolling and after rolling. is there.
(7) In any one of the above configurations (1) to (6), the shaped steel is a steel sheet pile having a joint portion 33.
According to the configuration of (7), it is possible to effectively suppress the occurrence of bending in a steel sheet pile that is easily bent.

(8) In the configuration of (7) above, the thickness of the bottom of the joint portion 33 or the thickness of the arm portion 32 connected to the joint portion 33 is used as the plate thickness at the left and right representative positions.
According to the configuration of (8) above, in the cross section orthogonal to the longitudinal direction, the plate thickness at a horizontal position during rolling is measured, so that the plate thickness can be measured more accurately and easily, and the occurrence of bending can be prevented. It can be suppressed more.

(9) A method of adjusting the leveling amount in rolling of a shaped steel according to an aspect of the present invention uses a plurality of rolling mills (for example, an intermediate rolling mill 12 and a finish rolling mill 13) and a plurality of hole dies to form a plurality of rolling mills. Is a method of adjusting the leveling amount in the rolling of a shaped steel when continuously rolling the material 2 of No. 1, which is the first material in the first rolling pass (for example, finish rolling by the K2 caliber of the finish rolling machine 13). When rolling 2, the bending amount δ of the first material 2 after rolling by the first rolling pass is measured, and for the first material 2, at the left and right representative positions before rolling by the first rolling pass, The thickness deviation before rolling showing the deviation of the sheet thickness is obtained, and the thickness deviation d _t after rolling showing the deviation of the sheet thickness at the left and right representative positions after the rolling by the first rolling pass is obtained, and the thickness deviation of the first rolling pass is calculated. For at least one of the second rolling pass (for example, the intermediate rolling by the intermediate rolling mill 12 performed immediately before the finish rolling) and the first rolling pass in which the rolling is performed immediately before, the leveling of the rolling mill corresponding to each rolling pass is performed. by adjusting the amount, at least one of the thickness deviation d _t after rolling thickness before deviation d _t and rolling, in the first run of the material 2, different, in the second rolling pass and the first rolling pass 2 The material 2 is rolled, the bending amount of the material 2 after rolling by the first rolling pass is measured, and the thickness deviation d _t before rolling and the thickness deviation d after rolling of the second material 2 are measured. seeking _t, bending amount of the first run of the material 2 [delta], the pre-rolling thickness deviation d _t and the thickness deviation d _t after _rolling, and bending amount of the two second material 2 [delta], the pre-rolling thickness deviation d _t and rolling with the thickness deviation d _t after, the amount of flexure δ thickness deviation before rolling is within the reference d _t and after rolling thickness deviation d _{t (e.g.,} the target value in FIG. 9) seeking, first run material and in 2 -th material 2, based on the the thickness deviation d _t before rolling curve amount and thickness deviation d _t after rolling [delta], it falls within the reference curve amount [delta] is, in the material 2 to be rolled on or after 3 knots calculating the thickness before rolling to target deviation d _t and the thickness deviation d _t after rolling, the thickness deviation d _t after rolling thickness before deviation d _t and rolling of the material 2 to be rolled after three th and the target The leveling amount of the rolling mill used in at least one of the second rolling pass and the first rolling pass is adjusted so as to achieve the above.
According to the configuration of (9) above, the same effect as that of (1) above can be obtained.

Next, examples performed by the present inventors will be described. In the example, the hat-shaped steel sheet pile 10H having an effective width of 900 mm and an effective height of 230 mm was rolled by the K2 caliber for performing the final thickness reduction as in the above-described embodiment. In the example, similarly to the above-described embodiment, the target thickness deviation before and after rolling is obtained using the thickness deviation d _t and the amount of bending of the first and second materials before and after rolling for the second and subsequent materials 2. The leveling amount was adjusted so as to be a deviation, and the intermediate rolling by the intermediate rolling mill 12 and the finish rolling by the K2 caliber were performed. Further, in the example, ten materials 2 were continuously rolled.

Further, in the example, as a comparison, rolling was performed by a conventional method in which an operator adjusts the leveling amount based on the actual product thickness results and the observation result of bending and performs rolling (comparative example 1). Further, rolling was performed by the method described in Japanese Patent Application Laid-Open No. 2009-119513, in which a web restraint guide and an arm restraint guide were installed on the front and rear surfaces of the K2 caliber (Comparative Example 2).
Table 1 shows the measurement results of the bending amount δ after rolling with the K2 caliber in Examples and Comparative Examples 1 and 2. In Table 1, the positive bending amount indicates the left bending amount δ, and the negative bending amount indicates the right bending amount δ. Further, the bending amount δ in Table 1 indicates the bending amount [mm] in a region 10 m from the tip of the material 2. Further, FIG. 12 shows the thickness deviation _dt before and after rolling in the first to third lines in the example. Further, FIG. 13 shows the thickness deviation d _t before and after rolling in the first to fifth lines in Comparative Example 1.

As shown in Table 1, in the example, the first and second materials 2 each had a left bend and a right bend. Then, as shown in FIG. 12, for the third and subsequent materials, the leveling amounts of the intermediate rolling mill 12 and the finish rolling mill 13 are adjusted so that the target value of the thickness deviation before and after rolling obtained from the equation (4) is achieved. did. As a result of rolling, it was confirmed that the third and subsequent materials 2 did not bend.

On the other hand, in Comparative Example 1, it was found that five materials 2 were required until the adjustment of the bending was completed, and it was confirmed that the accuracy of the bending adjustment was lower than that of the example. Further, as shown in FIG. 13, it was confirmed that the thickness deviation d _t before and after rolling could not be adjusted to a region where the bending amount was 0 at the third stage. Further, in Comparative Example 2, clogging occurred at the entry side guide of the K2 caliber at the first rolling, and misroll occurred, and clogging at the entry side guide of the K2 caliber occurred at the second rolling also, resulting in misroll. Therefore, the rolling of the third and subsequent materials 2 was stopped.

DESCRIPTION OF SYMBOLS 1 Rolling equipment 10 Heating furnace 11 Rough rolling mill 12 Intermediate rolling mill 13 Finishing rolling mill 130 Rolling roll 130A Upper roll 130B Lower roll 131 Rolling down device 132A, 132B Side guide 133 Plate thickness measuring instrument 134 Bending meter 135 Computational device 14 Conveying roll 2 Material 3 Steel sheet pile 30 Web 31 Flange 32 Arm part 33 Joint part

Claims (9)

Using a plurality of rolling mills and a plurality of hole die, continuously rolling a plurality of materials, a method of rolling a shaped steel,
When rolling the first material in the first rolling pass, the bending amount of the first material after rolling by the first rolling pass is measured,
For the first material, the thickness deviation before rolling indicating the deviation of the sheet thickness at the left and right representative positions before rolling by the first rolling pass is determined, and the left and right representative positions after rolling by the first rolling pass. In, to obtain the thickness deviation after rolling showing the deviation of the plate thickness,
By adjusting the leveling amount of the rolling mill corresponding to each rolling pass for at least one of the second rolling pass and the first rolling pass in which rolling is performed immediately before the first rolling pass, the pre-rolling is performed. At least one of the thickness deviation and the thickness deviation after the rolling is different from the first material under the condition that the second material is rolled in the second rolling pass and the first rolling pass,
Measuring the amount of bending of the second material after rolling by the first rolling pass,
For the second material, obtain the thickness deviation before the rolling and the thickness deviation after the rolling,
Using the bending amount in the first material, the thickness deviation before rolling and the thickness deviation after rolling, and the bending amount in the second material, the thickness deviation before rolling and the thickness deviation after rolling In order to obtain the thickness deviation before the rolling and the thickness deviation after the rolling in which the bending amount is within the standard,
Based on the thickness deviation before the rolling, the thickness deviation after the rolling, and the bending amount in the first material and the second material, the bending amount is within the standard, and the rolling is performed on the third and subsequent materials. In the material to calculate the target thickness deviation before rolling and the thickness deviation after rolling,
At least one of the second rolling pass and the first rolling pass so that the thickness deviation before the rolling and the thickness deviation after the rolling of the material rolled after the third rolling are targeted. A method for rolling a shaped steel, characterized in that the leveling amount of a rolling mill used in a rolling pass is adjusted to carry out rolling in the second rolling pass and the first rolling pass. When calculating the target thickness deviation before the rolling and the thickness deviation after the rolling in the material rolled after the third rolling, the thickness deviation before the rolling is set as x, and the thickness deviation after the rolling is set as y The method for rolling a shaped steel according to claim 1, wherein the thickness deviation before the rolling and the thickness deviation after the rolling in which the amount is within the standard are calculated by using the equation (4).

t _n ': Thickness deviation of _n-th material before rolling t _n : Thickness deviation of _n-th material after rolling a: Amount of bending of first material b: Amount of bending of second material When calculating the target thickness deviation before the rolling and the thickness deviation after the rolling in the material rolled after the third rolling,
In the coordinate system in which the horizontal axis represents the thickness deviation before rolling and the vertical axis represents the thickness deviation after rolling, the amount of change in the thickness deviation before rolling and the change in the thickness deviation after rolling are passed through the coordinates obtained from equation (4). Find a straight line with a slope of 1:1
The method of rolling a shaped steel according to claim 2, wherein the numerical values of the obtained coordinates on the straight line are the thickness deviation before the rolling and the thickness deviation after the rolling in which the bending amount is within the standard. .. When calculating the target thickness deviation before the rolling and the thickness deviation after the rolling in the material rolled after the third rolling, the numerical value of the coordinate on the straight line and the thickness deviation after the rolling is 0 is calculated. The method for rolling a shaped steel according to claim 3, wherein the thickness deviation before the rolling and the thickness deviation after the rolling are set so that the bending amount is within a standard. When calculating the target thickness deviation before the rolling and the thickness deviation after the rolling in the material rolled after the third rolling, the same as the thickness deviation before the first rolling or the second rolling on the straight line. 4. The rolling method for a shaped steel according to claim 3, wherein the numerical values of the coordinates are defined as the thickness deviation before the rolling and the thickness deviation after the rolling in which the bending amount is within the standard. The thickness deviation before the rolling and the thickness deviation after the rolling are ratios of plate thicknesses at the left and right representative positions of the material before rolling and after rolling, according to any one of claims 1 to 5. Rolling method for the shaped steel described. The said shaped steel is a steel sheet pile which has the joint part 33, The rolling method of the shaped steel of any one of Claims 1-6 characterized by the above-mentioned. The method for rolling the shaped steel according to claim 7, wherein the thickness of the bottom of the joint portion 33 or the thickness of the arm portion 32 connected to the joint portion 33 is used as the plate thickness at the left and right representative positions. .. Using a plurality of rolling mills and a plurality of hole die, when continuously rolling a plurality of materials, a method of adjusting the leveling amount in the rolling of shaped steel,
When rolling the first material in the first rolling pass, the bending amount of the first material after rolling by the first rolling pass is measured,
For the first material, the thickness deviation before rolling indicating the deviation of the sheet thickness at the left and right representative positions before rolling by the first rolling pass is determined, and the left and right representative positions after rolling by the first rolling pass. In, to obtain the thickness deviation after rolling showing the deviation of the plate thickness,
By adjusting the leveling amount of the rolling mill corresponding to each rolling pass for at least one of the second rolling pass and the first rolling pass in which rolling is performed immediately before the first rolling pass, the pre-rolling is performed. At least one of the thickness deviation and the thickness deviation after the rolling is different from the first material under the condition that the second material is rolled in the second rolling pass and the first rolling pass,
Measuring the amount of bending of the second material after rolling by the first rolling pass,
For the second material, obtain the thickness deviation before the rolling and the thickness deviation after the rolling,
Using the bending amount in the first material, the thickness deviation before rolling and the thickness deviation after rolling, and the bending amount in the second material, the thickness deviation before rolling and the thickness deviation after rolling In order to obtain the thickness deviation before the rolling and the thickness deviation after the rolling in which the bending amount is within the standard,
Based on the thickness deviation before the rolling, the thickness deviation after the rolling, and the bending amount in the first material and the second material, the bending amount is within the standard, and the rolling is performed on the third and subsequent materials. In the material to calculate the target thickness deviation before rolling and the thickness deviation after rolling,
At least one of the second rolling pass and the first rolling pass so that the thickness deviation before the rolling and the thickness deviation after the rolling of the material rolled after the third rolling are targeted. A method for adjusting the leveling amount in rolling of a shaped steel, which comprises adjusting the leveling amount of a rolling mill used in a rolling pass.

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