JPH04143009A - Rolling method for controlling deviation of web center of h-shape steel - Google Patents

Abstract

PURPOSE:To improve the accuracy by adjusting the pass center of mill during rolling based on the measured value of deviation of web center in the rolling using a universal rolling mill for H-shape steel with horizontal roll of which the width is variable. CONSTITUTION:The width of the horizontal rolls 92 of the finishing universal rolling mill is bisected and the rolls are made into such a structure as the width can be on-line adjusted. At the time of rolling for reducing the web height by one pass or some passes, the vertical position of the flange part of a rolled stock to the pass center of mill is adjusted during rolling with roller guides 82 which are arranged near the inlet side of rolling mill based on measured values over the entire length of rolled stock that are detected with an instrument for measuring web center deviation. In this way, hot rolling of H-shape steel can be done while minimizing the deviation of web center of product.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for hot rolling H-section steel used in fields such as construction and civil engineering, and particularly to a method for controlling web center deviation of IJ section steel. be.

(Prior art) Conventionally, when manufacturing H-beam steel by rolling, rolls of the same width are used at the same rolling chance, so the inner width of the flange of the H-beam can be kept constant, but the flange thickness, etc. When changing the cross-sectional dimensions of the web, the web height changes accordingly, resulting in many products in the same series whose nominal dimensions and web height do not match. These relationships are shown in FIG. 1, where Ho, If, and H2 are the web heights and -6 is the flange inner width. tfo<tf,
If <If2, then when -0 is constant, HO<
Hl<82.

On the other hand, when manufacturing H-shaped ropes by welding, thick plates can be selected and used to achieve a predetermined size, so even if the cross-sectional dimensions change in the same frieze, the web height All values can be kept constant. These relationships are the second
As shown in the figure, the reference numerals in the figure are the same as in FIG. -0,
Since −1 and −2 can be changed, Ho, 3, and H2 can also be kept constant.

The present applicant has already proposed several means for solving the above-mentioned problems regarding the conventional method of rolling a section having a flange.

In Japanese Patent Application No. 1-149851, a universal mill 90 having a vertical roll 94 as shown in FIG. 3 and a two-part horizontal roll 92 with variable width is used for rolling as shown in FIGS. 4(a) and (b). We proposed a method in which the web height is reduced by applying one pass or multiple passes of reverse rolling in the finishing universal mill.

Furthermore, in the same patent application No. 1-149851,
As shown in Figures (a) and (1)), two finishing universal mills are used: a finishing universal mill (UP+) consisting of fixed width horizontal rolls and a finishing universal mill (UF2) consisting of variable width horizontal rolls. A method for height reduction rolling was proposed.

According to these inventions, it is possible to make the outer web height dimensions of H-beam steel of the same series constant with one type of roll, and without being restricted by the horizontal roll width of a rough universal rolling mill. H-beam steel with a free web height can be manufactured using the same rolls at the same rolling chance, resulting in a significant reduction in the number of rolls owned and a significant improvement in roll consumption.

(Problems to be Solved by the Invention) Regarding the above-mentioned hot rolling method for H-section steel proposed by the present applicant, the present inventor has repeatedly conducted numerous model mill experiments and has found the following problems. revealed.

(1) When manufacturing H-section steel using the method of rolling a section with a flange proposed by the applicant, depending on the amount of reduction in web height, the web center of the product may be biased as shown in the 6th leap. It becomes a problem. The center deviation amount S is expressed as 5-(ab)/2.

In other words, when the amount of web height reduction exceeds a certain range,
The center deviation of the web increases rapidly, resulting in a product that does not satisfy the predetermined tolerance. According to JIS G 3192, the allowable range for center deviation is ±3.0 for webs with a height of 3001 or less.
mm, ±4 for web height exceeding 300 mm
．． It is defined as 5 gates.

(2) As a method for preventing deterioration of the web center deviation of the H-section steel during the web height reduction rolling, the present applicant has developed a technique disclosed in, for example, Japanese Patent Application No. 2-7812.
This is a method for preventing the web center deviation of the H-section steel material before web height reduction rolling from being worsened by web height reduction rolling, and is not intended to correct the center deviation. Therefore, the large web center deviation that occurred during the rolling process before finish rolling is not corrected by the above-mentioned web height reduction rolling proposed by the applicant, and remains as a web center deviation of the product, resulting in deviations from dimensional tolerances. Cause.

Here, the object of the present invention is to make it possible to freely change the inner width of the nib and to manufacture multiple series of H-beams using the same universal finishing mill, by using the horizontal rolls of the same universal finishing mill. , when manufacturing H-beam steel with a constant outer dimension of web height for different sizes of flange thickness, it is possible to suppress the deviation of the web center of the product to a small level so that it does not deviate from the specified tolerance over the entire length. An object of the present invention is to provide a method for controlling web center deviation of an H-section steel.

(Means for Solving the Problem) In order to solve the problem, the present inventor conducted an experiment of web height reduction rolling of H-section steel using a finishing universal mill having variable width horizontal rolls, and The following facts were discovered from the experimental data.

In a universal mill 74 having a vertical roll 70 and a variable width horizontal roll 72 as shown in FIG. Rolling is performed to reduce the web height by shifting it up and down by e with respect to the bus center,
Web center deviation amount of H-beam steel after rolling 5 (-(a-b)/
2) was investigated. 7(a) is a static sectional view of FIG. 7(a), FIG. 7(C) is a cc' sectional view, and FIG. 7(d) is a BB' sectional view.

The results are shown graphically in Figure 8, where e on the horizontal axis represents the deviation between the flange center of the rolled material and the mill bus center on the mill entry side, + means the flange center is above the mill pass center, and + means the flange center is above the mill pass center; This means that the flange center is on the lower side with respect to the mill pass center. When the web center deviation S on the vertical axis is 0, a>b, which means that the flange of the product after rolling has been placed above the mill pass center. Conversely, if S is -, a
<b, which indicates that the flange of the product after rolling has been placed lower than the mill pass center.

As shown in Figure 8, e and S have an almost linear relationship,
The gradient is a constant that changes depending on rolling conditions (web thickness, flange thickness, flange width, web radius, web height, amount of reduction in web height, rolling material, rolling temperature, etc.).

Based on the facts clarified above, the correlation between the constant necessary for controlling the web height and various rolling parameters was determined in the form of a regression equation through experiments, and the web center deviation S of the material before rolling was detected. Then, from the relationship between the detected value and the clearance shown in Fig. 8, e necessary to correct the web center deviation S is determined, and the position of the roller guide installed close to the entrance side of the rolling mill is adjusted based on this value. A method of feedforward controlling the vertical position of the flanged part of a rolled material with respect to the mill pass center during rolling, ■ Detecting the web center deviation S of the H-section steel after rolling and adjusting it to the detected value Fig. 8 From the relationship, e necessary to correct the web center deviation S is determined, and the position of the roller guide placed close to the entrance side of the rolling mill is adjusted based on this value, and the flange part of the material to be rolled is adjusted in the vertical direction with respect to the mill pass center. Feed Ha while rolling position.

■ A method of controlling the vertical position of the flange part of the rolled material with respect to the mill pass center during rolling by combining both methods (■) and (■) above. We have completed a web center deviation control rolling method that has a small web center deviation and does not produce products that deviate from dimensional tolerances.

Here, the gist of the present invention is a HJII hot rolling method that is performed through breakdown rolling, rough universal rolling, edger rolling, and finishing rolling, and which comprises dividing the horizontal roll width of the finishing universal rolling mill into two. In a rolling method in which the web height is reduced by rolling one bus or multiple buses in the finishing universal rolling mill, the width can be adjusted online, and the rolling mill is installed on the upstream and/or downstream side of the rolling mill. Based on the web center deviation measurement value over the entire length of the rolled material detected by the web center deviation measuring device, a roller guide placed close to the entry side of the finishing universal rolling mill is used to adjust the mill pass center of the flange part of the rolled material. This is a method for controlling web center deviation of H-section steel, which is characterized by adjusting the vertical position during rolling.

According to preferred aspect B of the present invention, the roller guide disposed close to the entry side of the finishing universal rolling mill is a web guide that restrains the web surface of the rolled material from above and below.

According to yet another preferred aspect, the roller guide disposed close to the entry side of the finishing universal rolling mill is a flange guide that restrains the flange end of the material to be rolled from above and below.

(Operation) The present invention will be described in more detail with reference to the accompanying drawings.

The rolling method according to the present invention can be carried out, for example, using a rolling line shown in FIG. 4(a).

First, according to the rolling method of the present invention, breakdown rolling may be performed in the same manner as in the conventional method, whereby the rolled material is rolled into a beam blank. After that, the rolled material is finished to a flange width, flange thickness, and web thickness that are close to the final dimensions through intermediate rolling using a rough universal rolling mill (Ull) (rough universal mill) and an engine rolling mill (E) (engineer mill). It will be done.

The intermediate rolled steel section thus obtained is subjected to one pass or multiple passes of web height reduction rolling by a finishing universal mill (finishing universal mill) consisting of a two-part variable width horizontal roll and a vertical roll. Several tens of meters
The outer dimension of the web height of the H-section steel can be freely changed within the range of m. This finishing universal mill rolling may be performed by multiple reverse rollings if necessary.

9 and 10 show a side view of the web height reduction rolling process according to the present invention.

In the 9th IZ (a), et al., a web roller guide 80 installed close to the entry side of a finishing universal rolling mill 74 having a variable width horizontal roll 72 is used to roll the web surface of an H-shaped steel 76, which is a material to be rolled, from above and below. This is to adjust the vertical position of the flange while restraining it during rolling.

In Fig. 9(a), the rolled material before rolling is S = (at-b
+)/2 represents the case where the web center deviation S is a, <b, and FIG. 9(b) shows that the rolled material before rolling is 5=
This shows the case where the web center deviation S is (ab,)/2 and al>b+.

In Fig. 9(a), since a<J, the ego, that is, the flange center is moved upward by 1 point with respect to the path center.
e1# Hold the web roller guide 8 in the
Adjust 0. Further, in FIG. 9(b), since a>b, the web roller guide 80 is adjusted so that e<0, that is, the flange center is held at a position ler downward from the pass center. That is, the 911th
In F(a) and (b), by vertically shifting the web center of the rolled material having web center deviation by e-3 with respect to the mill pass center, the product after web height reduction rolling is a 2 L =, b 2, which makes it possible to correct the web center deviation.

Here, when e-3>0, the web center is located above the mil-pass center, and when e-5<0, it means that the web center is located below the mil-pass center.

FIGS. 10(a) and 10(b) show that H, which is a material to be rolled, is
The flange ends of the shaped copper 76 are restrained from above and below, and the vertical position of the flange is adjusted during rolling.

FIG. 10(a) shows that the rolled material before rolling is S = (at-b
+)/2 represents the case where the web center deviation S is a, <b, and Fig. 10(b) shows that the rolled material before rolling is 5
-(ab,)/2, which represents the case where the web center deviation S is a,>b.

Figure 1O (Since a, <b in al, ego
That is, the flange guide is adjusted so that the flange center is held at a position ler apart above the pass center. Also, in Figure 10, etc.), since a, > b+, e<0, that is, tell the flange center to be lower than the path center! Adjust the flange guide to hold it in the correct position. As a result, the product after web height reduction rolling becomes a2#b2, making it possible to correct the web center deviation.

Next, the above-mentioned web roller guide and flange roller guide used in the present invention will be explained.

As can be seen from FIG. 9 and FIG. 1011i1, the web roller guide 80 and the flange roller guide 82 each have one or more rolls (in the illustrated example, a roll There is no particular restriction as long as it has the following two features.

Regarding the installation location of each roller guide, it is desirable to install it as close to the finishing universal mill 74 as possible.

In addition, in the case of a web roller guide, the gap between the horizontal roller and the web surface, and in the case of a flange roll guide, the gap between the vertical roller and the flange surface should be kept as small as possible; Generally, a thickness of about II to 2 mm is required so as not to interfere with loading and conveyance.

In either case, the horizontal rollers and vertical rollers are not driven as a general rule, but they are used as auxiliary drives to facilitate the biting of the rolled material and to provide the effect of conveying the rolled material using guides. Good too.

11 to 13 show control block diagrams for implementing the web center deviation control method according to the present invention.

A web center deviation measuring device 90 is installed on the upstream side of the finishing universal rolling mill 74, and FIG. The opening degree of the flange roller guide 82 is controlled during rolling via the flange guide position adjustment device ff 92 arranged close to the entrance side of the rolling mill, in order to minimize the deviation of the web center of the H-section steel after rolling. It is something to do.

The opening command for the flange guide position adjustment device 92 is based on the detected value of the entrance web center deviation, the rolling conditions instructed for each rolling bus from the main process computer, and the material temperature during rolling measured by a thermometer. Then, a calculation unit calculates an appropriate amount of guide position correction, and a command is issued in a timely manner so that the guide position is adjusted when the measuring position of the web center deviation S is rolled by the rolling mill.

FIG. 12 shows a web center deviation measuring device 94 installed downstream of the finishing universal rolling mill 74, and based on the measured value of the web center deviation over the entire length of the rolled material (H-beam) detected by this measuring device 94. , the opening degree of the flange roller guide 82 is controlled during rolling via a flange guide position adjustment device 92 disposed close to the entrance side of the rolling mill to minimize the deviation of the web center of the H-section steel after rolling. be. Based on the detected web center deviation on the exit side of the rolling mill, the rolling conditions instructed for each rolling pass from the main process computer, and the material temperature during rolling measured with a thermometer, a calculator determines the appropriate guide position. The correction amount is calculated, and an opening command is issued to the flange guide position adjustment device 92 without delay. 12th
In the case shown in the figure, since it is feedback control, it is desirable to place the web center deviation measuring device 94 installed on the exit side of the rolling mill as close to the rolling mill as possible, which takes the processing time of the computing unit and the adjustment time of the guide position adjustment device. must be kept as short as possible.

FIG. 13 shows that web center deviation measuring devices 90,94 are provided on both the upstream and downstream sides of the finishing universal roller 74 having variable width horizontal rolls, and the web over the entire length of the rolled material obtained by each measuring device is Input the center deviation measurement value to the calculator. Therefore, based on the rolling conditions input for each rolling pass from the main process computer and the material temperature during rolling measured with a thermometer, the web center deviation S of the H-beam steel after rolling is minimized. An appropriate guide position correction amount is calculated, and an opening command is issued to the flange guide position adjustment device 92 at an appropriate timing. According to the control system of this configuration, more accurate web center deviation control is possible than when feedforward control or feedback control as shown in FIGS. 11 and 12 is performed alone.

In the above explanation, the web center deviation was controlled by adjusting the position of the flange center up and down using the flange guide, but as mentioned above, by adjusting the position of the flange center up and down using the web guide, The above explanation also applies to the case of controlling bias.

As a web center deviation measuring device used in carrying out the present invention, for example, the one disclosed in Japanese Patent Application Laid-Open No. 58-179515 can be used.

In addition, in the above explanation, we have described the case where the web height is reduced in one bath using a universal mill having variable width horizontal rolls and finished to a predetermined dimension of HJ [ii], but web height reduction rolling in multiple buses is The same applies to the case of finishing a product, and the present invention may be applied to each bus with the configurations shown in FIGS. 1n to 13. In this case, the measuring device used to measure web center deviation on the upstream side of the rolling mill may also be used as a web center deviation measuring device on the downstream side in the next bus, or vice versa. good.

Next, the effects of the present invention will be explained in more detail based on examples thereof.

Example 1 In this example, the rolling line shown in FIG.
The method of the present invention was applied when hot rolling H-beam steel of the X200 series with constant web height external dimensions.First, after heating the continuous casting bloom, reverse rolling was performed in a breakdown mill with a roll hole type. , a beam blank was modeled. Further, reverse rolling was performed using a rough universal mill (IIR) and an Enger mill (E) to finish the product to a shape and dimensions close to the flange thickness, web thickness, and flange width of the product.

Here, the horizontal roll width of UR is 386+++ m, and the horizontal roll side surface has a taper of 5°. [The material after IR rolling is rolled in a finishing universal mill consisting of two horizontal rolls with variable width, to reduce the web height for up to three passes so that the inner surface of the flange is in contact with the guide water roll, and at the same time to make the web thickness uniform. The product was made by shaping and rolling with the main purpose of correcting the perpendicularity of the flange and web.

Table 1 summarizes the results of measuring the web center deviation of products in the case of implementing the present invention in the form of average values (average values of absolute values of web center deviation) and standard deviations. In this example, the arrangement of web roller guides shown in FIGS. 9(a) and 9(b) is adopted, and a web center deviation measuring device installed on the upstream side of the variable width universal rolling mill measures the web center deviation for each rolling pass. was detected, and web center deviation control was performed by adjusting the vertical position of a web roller guide disposed close to the entrance side of the rolling mill using a control system equivalent to the control system shown in FIG. For comparison, the table also shows the results of measuring web center deviation when conventional rolling was performed without implementing the control of the present invention.

From Table 1, it can be seen that when the present invention was implemented, a product with significantly smaller web center deviation and good dimensional accuracy was obtained compared to when the present invention was not implemented.

Example 2 In this example, as in Example 1, the present invention was applied when hot rolling an 8400 x 200 series H-beam steel with a constant external dimension of web height on the rolling line shown in Fig. 4(a). Applied.

In the case of this example, the steps from breakdown rolling to rough universal rolling and edger rolling were the same as in Example 1 described above. After UR rolling, the material is rolled in one bath to reduce the web height in a finishing universal mill consisting of two horizontal rolls with variable width, so that the inner surface of the flange is in contact with the side surface of the horizontal roll, and at the same time, the web thickness is made uniform. The product was then shaped and rolled with the main purpose of correcting the perpendicularity of the flange and web.

Table 2 summarizes the results of measuring the web center deviation of products in the case of carrying out the present invention in the form of average values and standard deviations.

In this example, web center deviation was detected using web center deviation measuring devices installed on the upstream and downstream sides of a variable width universal rolling mill, and a control system equivalent to the control system shown in Figure 3 was used to roll the mill. Web center deviation was controlled by vertically adjusting the flange roller guide located close to the machine entry side. For comparison, the table also shows the results of measuring web center deviation when conventional rolling was performed without implementing the control of the present invention.

From Table 2, it can be seen that when the present invention was implemented, a product with significantly smaller web center deviation and good dimensional accuracy was obtained compared to the case where the present invention was not implemented.

(Effects of the Invention) As detailed above, according to the present invention, when H-section steel is manufactured using a universal rolling mill having the same variable-width horizontal roll, or when H-section steel is manufactured using a universal rolling mill having the same variable-width horizontal roll, When manufacturing an H-beam steel having a constant outer dimension in terms of web height, the H-beam steel can be hot rolled while minimizing the deviation of the web center of the product. As a result, even when a large change in web height is required, a product with excellent dimensional accuracy can be rolled, and the present invention has extremely high industrial utility value.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the current product dimensional system of H-beam steel made by rolling; Part 2 is an explanatory diagram of the current product dimensional system of H-beam steel made by welding. Figure 3 is an explanatory diagram of the current product dimensional system of H-beam steel made by welding. An explanatory diagram showing the state of a universal finishing rolling mill: Fig. 4 (a), (1)) is an explanatory diagram showing an example of a rolling mill layout for H-beam steel when implementing the present invention; Fig. 5 (
a), (+)) are explanatory diagrams showing an example of the rolling mill layout for H-beam steel when carrying out the present invention; Fig. 6 is an explanatory diagram of the web center deviation of H-beam steel; Fig. 7 (a), (bl, (
C) and (d) are explanatory diagrams showing the occurrence of web center deviation due to web height reduction rolling of H-section steel; Figure 8 shows flange vertical movement and web center during web height reduction rolling of H-section steel Graphs showing the relationship of bias: FIGS. 9(a), (b) and 10(a), (b) are explanatory diagrams showing the state of rolling of the H-beam steel according to the present invention; and FIG. 11 ~FIG. 13 is a web center bias control diagram when implementing the present invention. 70: Vertical roll 72: Horizontal roll 74: Finishing universal rolling mill 76: H-shaped steel (rolled material) 80: Web roller guide 82: Flange roller guide

Claims (1)

[Claims] A method for hot rolling H-section steel through breakdown rolling, rough universal rolling, engagement rolling and finish rolling, in which the horizontal roll width of the finishing universal rolling mill is divided into two and the width can be adjusted online, A rolled material detected by a web center deviation measuring device installed upstream and/or downstream of the rolling mill in a rolling method in which the web height is reduced by rolling one pass or multiple passes in the finishing universal rolling mill. Adjusting the vertical position of the flange portion of the material to be rolled with respect to the mill pass center during rolling using a roller guide placed close to the entry side of the finishing universal rolling mill based on the measured web center deviation over the entire length. H characterized by
Web center deviation control rolling method for section steel.