WO1995017269A1

WO1995017269A1 - H-steel manufacturing method

Info

Publication number: WO1995017269A1
Application number: PCT/JP1994/002123
Authority: WO
Inventors: Yoshiaki Kusaba
Original assignee: Sumitomo Metal Industries, Ltd.
Priority date: 1993-12-20
Filing date: 1994-12-16
Publication date: 1995-06-29
Also published as: EP0736341A1; JP2943326B2; KR100254493B1; EP0736341A4; AU681219B2; AU1200795A

Abstract

This invention relates to a method of manufacturing H-steel used for building. The method according to the present invention is used for the intermediate rolling of H-steel in a mill unit UT in which a universal roughing mill UR and a universal edger mill UE are arranged close to each other, characterized by pressing down free end portions of a flange by a horizontal roll of the UE with the width of the horizontal roll set smaller than that of a corresponding roll of the UR and with an outer surface of the flange held by a vertical roll of the UE, and pressing down the flange in the direction of the thickness thereof with the horizontal roll of the UE set width-variable and with a bore mold formed by the horizontal roll and vertical roll. This enables the buckling of the flange during the pressing of the flange in the widthwise direction thereof by the UE will to be prevented, and H-steel having a dimensional precision/comparable to that of welded H-steel to be manufactured by hot rolling.

Description

Specification

Title of the invention Manufacturing method of H-section steel

Technical field

The present invention relates to a method for hot rolling of high-dimensional precision H-section steel used for construction, and more particularly to hot rolling of a multi-size H-section by hot rolling using a group of universal mills. O Background technology for manufacturing with the required dimensional accuracy

The building's steel frame is mainly constructed of H-beams. With the rise of buildings, multi-size H-beams and H-beams with high dimensional accuracy have become necessary. However, the gap between the ridges and flanges of hot-rolled H-section steel specified in JIS (Japanese Industrial Standards) is 25 mm, which is rough, 50 mm, and the rolling dimension tolerance is wide. For this purpose, a welded H-section steel is used.

Figure 1 is a diagram showing the cross-sectional shape of the H-section steel and the dimensions of each part. H web height, B is the flange width, the web thickness, t ₂ is the length of the flange thickness, l, b ₂ from © Ebb to the flange tip.

The name of the H-section is displayed as H500XB200X10Z16. H 500 indicates a web height of 500 mm, B 200 indicates a flange width of 200 mm, and 10 6 indicates a web thickness of lOmmZ and a flange thickness of 16 mm. The dimensional tolerance of welded H-section steel specified by the Japan Steel Structure Association Standard is stricter than that of hot-rolled H-section steel (hereinafter, hot-rolled H-section steel is simply referred to as “H-section steel”). When the web height is 500 occluded, the tolerance of the web height is ± 1.5 mm for the welded H-section and ± 3.0 omission for the H-section.

If the dimensions of the webs and flanges are different, the appearance may be impaired when the structure is used, and failure may occur in the joints, etc., causing a decrease in strength. In particular, if the deviation S from the center of the flange of the web (S-^!-B / S in Fig. 1, hereinafter referred to as “web center deviation”) increases, the load of the deviation is applied, and the strength of the structure decreases. I do. Therefore, the center deviation of the web is ± 2.5 mm for welded H-beams with a web height of 300 mm or more, and ± 3.5 hidden for H-beams.

In conventional rolling of H-section steel, a 铸 piece or a slab is converted to a dock bone type by a double hole type roll roughing mill (2 Hi-breakdown mill, hereinafter referred to as “2 Hi-BD mill”). After the rough material is formed, a universal rough mill (hereinafter referred to as “UR mill”), a double roll edge yam mill (hereinafter referred to as “2 Hi-E mill”) and a universal finishing mill (hereinafter referred to as “2 Hi-E mill”) Hereinafter, it is described as a UF mill. Intermediate rolling is performed by reciprocating rolling between the UR mill and the 2 Hi-E mill, and the H-section is finished by one-pass rolling in a UF mill.

2 Several types of Etsuja hole types are provided on the roll of the Hi-E mill in the roll width direction. For example, when manufacturing multi-size H-section steel, the edge-ear hole type with different web height and flange width (H600X200, H550X200, H500X200, or H200X100, H300X150, H400X200, 3 sizes) Etc.) are engraved on one roll.

FIG. 2 is a diagram showing a cross-section of a plurality of cavities and rolled material engraved on the rolls of the 2 Hi-E mill. 5 is the upper edge roll, 6 is the lower edge roll, of the engraved holes (A) is the hole for H500X200, (B) is the hole for H550X200, and (C) is the hole for H600X200 This shows the hole type.

In the case of manufacturing H-shape with constant outer dimensions, which will be described later, it is necessary to engrave an edger single hole type with the same web height and flange width but different web thickness and flange thickness. In general, the dimensional accuracy decreases when the thickness of the flange and the flange is reduced. On the other hand, since the dimensional accuracy of each part of the H-section steel with a constant outer dimension is required to be comparable to that of the welded H-section steel, 2 Hi-E mill It was difficult to produce this on a rolling line using a roll of.

Fig. 3 shows a front view of a roll and a longitudinal section of a rolled material or H-beam to explain the method of manufacturing an H-beam using a 2Hi-E mill for an edger mill.

Fig. 3 (a) is a diagram showing the state of rough rolling by an UR mill having upper horizontal roll 1, lower horizontal roll 2, and vertical rolls 3 and 4.At this stage, first, the rough shape of H-section steel is formed. You.

FIG. 3 (b) is a diagram showing the state of rough rolling by a 2Hi-E mill having only the upper and lower eager rolls 5,6. In this figure, one hole type of the roll of FIG. 2 is taken out and shown. At this stage, ensure the accuracy of the dimensions of each part such as the flange width and the center of the rib (the center where the web is located at the center of the flange). That is, the rolls 5 and 6 lower the flange tip 7 of the rolled material to correct the web center deviation of the rolled material. At this time, in order to enhance this straightening effect, the inner surface of the rolled material flange is constrained by rolls so that the rolled material does not shift in the left-right direction.

FIG. 3 (c) is a view showing a state of finish rolling by a UF mill having an upper horizontal roll 8, a lower horizontal roll 9, and vertical rolls 10 and 11. At this stage, the horizontal rolls 8 and 9 are brought into contact with the web and the inner surface of the flange, and the vertical rolls 10 and 11 are brought into contact with the outer surface of the flange to perform finish rolling, thereby obtaining an H-section steel having product dimensions.

In the above rough rolling of the UR mill (Fig. 3 (a)), the width of the flange width of the rolled material is not uniform due to the incomplete positioning of the material and the misalignment of the upper and lower horizontal rolls. If there is any deviation, the next 2 Hi-E mill will attempt to correct this, but some flanges will be subjected to strong pressure, and the flanges will buckle and cannot be corrected.

FIG. 4 is a front view of a roll and a longitudinal sectional view of a rolled material showing an example in which buckling has occurred in a flange portion in a 2Hi-E mill. Because some flanges bend, The width of the flange cannot be reduced and the center deviation of the web cannot be corrected, and the finish rolling by the UF mill cannot correct the unevenness of the flange width, and returns to the original rough rolling state. As a result, the web center bias cannot be corrected.

In the 2 Hi_E mill, the inner surface of the flange is in contact with the roll, and the flange is inclined outward. If the flange thickness is reduced, buckling occurs when the flange tip 7 is pressed down. Therefore, an H-section steel rolling line including a 2Hi-E mill cannot produce an H-section steel with strict dimensional accuracy. Various means have been proposed for a long time to improve the dimensional accuracy of H-section steel products at the edge-year mill stage. For example, WALZWERKSWESEN (J. PUPPE und), a section steel rolling handbook published in 1934

G. STAUBER, DUESSELDORF VERLAGSTHALE IZEN M.B.H.), page 304, Figures 26. a to c show 4-roll configuration universal type edger mill (hereinafter referred to as "UE mill"). Is shown in cross section. In this example, buckling of the flange as shown in FIG. 4 can be prevented by the action of the vertical roll, so that the effect of correcting the center deviation of the web increases.

However, the mill was not used in Europe, the United States, or Japan for the following reasons: In other words, in this UE mill, the rolled material is completely constrained and rolled on two horizontal rolls and two vertical rolls. Therefore, when manufacturing different types of H-section steels of various sizes, horizontal rolls are required for each size. It is necessary to keep it, and when manufacturing H-section steels with a constant outer dimension, there is the disadvantage that the number of portals further increases.

H-beams of the size corresponding to the load are used for the steel frame of the high-rise building. Therefore, various types of H-beams with different nominal dimensions are manufactured. However, even in the case of a single nominal size H-section steel, the actual height and flange width are different, and using this not only makes joining difficult but also detracts from aesthetics. Manufacture of various types of H-beams with different nominal dimensions requires hole mills and universal mills according to the web height. Many rolling methods have been proposed to reduce the number of these holes. For example, the inventor has already reduced the height of the web using a UF mill (Japanese Patent Application Laid-Open No. 2-84203, US Patent No. 4958509, British Patent 2222796, Australian Patent 625679, Korean Patent No. 51420), UR mill or A method of reducing the height of the web using one of the UF mills (Japanese Patent Laid-Open No. 4-258301, US Patent No. 5287715, Australian Patent No. 640553, European Patent Publication No. 0498733, Korean Application No. 92-1775) was proposed. . In addition, Japanese Patent Application Laid-Open Nos. 59-133902, 60-82201, 60-83702, and 60-83702 disclose methods for reducing the web height in intermediate rolling or finish rolling. JP-A-60-1 18301 and JP-A-62-93008 can be mentioned. In addition, Japanese Patent Application Laid-Open Nos. 63-30102, 63-72402, 63-168204, and 63-168204 disclose a method of increasing the height of the web in intermediate rolling or finish rolling. JP-A-61-262403, JP-A-62-161403, and JP-A-61-262402 and JP-A-61-262404 disclose methods of reducing or enlarging the height of a tube. Gazettes.

Regardless of the method of reducing or expanding the web height, the flange tip is not constrained by the roll and the flange width can be expanded freely. For this reason, especially when the height of the web is reduced, the material flows from the web to the flange, causing the flange width to expand by about 4% or more, increasing the center deviation of the web, and deviating from the tolerance. .

Thus, in the conventional method, even when the height of the web is changed, the center deviation of the web becomes large, and in some cases, there is a problem that the correction effect by the Etzger mill is impaired.

A section steel with a constant outer dimension means, for example, as shown in Fig. 1 (a) and), the section height H and the flange width B of multiple H sections are equal, and the web thickness And a series of H-section steel having different flange thickness t _2.

Manufacture of H-section steels with constant external dimensions requires hole rolls and universal mills according to the web thickness and flange thickness, and reduces the weight of the product by reducing the thickness of the ribs and flanges. Lighter, but more expensive to manufacture. Therefore, conventionally, welded H-section steel has been used as the H-section steel with a constant outer dimension. Disclosure of the invention

An object of the present invention is to provide a method for manufacturing a high-dimensional precision H-section steel by hot rolling, and in particular, to provide a group of universal mills of various types of H-section steels having different nominal sizes and H-section steels having a constant outer dimension. An object of the present invention is to provide a method for hot rolling with a dimensional accuracy comparable to that of a welded H-section steel.

The gist of the present invention is a method of manufacturing an H-section steel shown in the following (1) to (5), the contents of which will be described based on the line configuration shown in FIG.

(1) One mill group (OJT) in which a universal roughing mill (UR) consisting of four rolls each and a UNIVA sullet jar mill (UE) are placed in close proximity to each other at least in the final stage of the intermediate rolling process The width of the horizontal roll of the universal edger mill is smaller than the width of the horizontal roll of the universal coarse mill, and the outer surface of the flange of the coarse material is universal. A method of manufacturing H-section steel in which the edge roll is constrained by vertical rolls and the tip of the flange is lowered by horizontal rolls.

(2) A method for producing an H-section steel, in which the intermediate rolling of the above (1) is performed, and the subsequent finishing rolling is performed using a universal finishing mill (UF) arranged close to the mill group (UT).

A universal mill having a variable width horizontal roll may be used as the finishing mill.

(3) Universal coarse mill (UR) consisting of 4 rolls each A method for producing an H-section steel, in which one mill group (UT), in which a saluette jar mill (UE) is disposed in close proximity, is used in at least the final stage of the intermediate rolling process. A method of manufacturing H-section steel in which the width of the horizontal roll of the mill is variable, a hole is formed by the horizontal roll and the vertical roll of the universal edge yard mill, the inner and outer surfaces of the flange are constrained by rolls, and the tip of the flange is lowered by the horizontal roll .

(4) A method for producing an H-section steel, in which the intermediate rolling described in (3) above is performed, and the subsequent finish rolling is performed using a universal finishing mill (OJF) arranged in close proximity to the mill group.

(5) The method for producing an H-section steel according to any one of (1) to (4), wherein the height of the hub is reduced in the final pass of the universal etching mill.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows the dimensions of each section of the H-section.

FIG. 2 is a diagram showing a cross section of a plurality of cavities and rolled material engraved on a roll of a 2Hi edge mill (2Hi-E mill).

FIG. 3 is a front view of a roll and a longitudinal sectional view of a rolled material for explaining a conventional method for rolling an H-section steel.

FIG. 4 is a front view of a roll and a longitudinal sectional view of a rolled material showing examples of buckling of a flange and deviation of the center of a web in a conventional agedger mill.

FIG. 5 is a diagram showing an H-section steel production line for explaining the method of the present invention. (A) shows a H-beam production line with a UR mill and a UE mill placed close to each other, and (b) shows an H-beam with a UR mill and a UE mill and a UF mill with variable width horizontal rolls placed close together. Fig. (C) shows the H-section production line in which a UR mill and a UE mill with variable width horizontal rolls are placed in close proximity, and (d) shows a UR mill, UE mill and UF. FIG. 3 is a view showing a production line for an H-section steel in which mills are arranged close to each other and horizontal rolls of variable width are used for a UE mill and a UF mill.

FIG. 6 is a diagram illustrating a universal etching mill used in the rolling method of the present invention.

FIG. 3 is a front view of a roll and a longitudinal sectional view of the rolled material, showing the shape and positional relationship between each roll and the rolled material (UE mill).

Figure 7 shows an example of rolling using a universal edge yard mill (Fig. (A)) and a universal finishing mill (Fig. (B)) equipped with a variable width two-piece horizontal roll. It is a longitudinal cross-sectional view.

Fig. 8 is a front view of a horizontal roll and a vertical roll, and a vertical cross-sectional view of a rolled material, showing an example of a variable width two-split horizontal roll of a universal Etsuger mill (UE mill).

FIG. 9 is a diagram showing a cross section of a rough material subjected to test rolling.

Figure 10 shows the longitudinal webs of the H-sections of Fig. 9 and their rolled materials. It is a figure which shows the measured value of center deviation.

FIG. 11 is a diagram showing the measurement results of the flange width when the web height is reduced by the method of the present invention.

FIG. 12 is a diagram showing the dimensional accuracy of various H-section steels obtained in the examples and the manufacturing tolerances of the hot-rolled H-section steel and the welded H-section steel.

FIG. 13 is a view showing a hole shape of a roll for a 2Hi breakdown minole (2Hi-BD mill).

Fig. 14 is a diagram showing the pass schedule for rolling H-section steel in a 2Hi breakdown mill (2Hi-BD mill).

FIG. 15 is a diagram showing a pass schedule when an H-section steel is rolled along the line shown in FIG. 5 (d).

FIG. 16 is a diagram showing a cross section of a grooved die and a rolled material engraved on a roll for a 2Hi edge yaminole (2Hi-E mill).

Fig. 17 shows the pass schedule when a conventional 2Hi-E mill is used instead of the universal edger mill (UE mill) in the mill line of Fig. 5 (d) as a comparative example and an H-section steel is rolled. FIG.

FIG. 18 is a diagram showing the change in the center deviation of the web of the H-section steel in the longitudinal direction of the rolled material. BEST MODE FOR CARRYING OUT THE INVENTION

The reason why the method for producing the H-section steel of the present invention is determined as described above will be described in detail below.

FIG. 5 is a view showing a production line for an H-section steel according to the method of the present invention. Figure (a) shows a line for producing an H-section steel in which a UR mill and a UE mill are arranged close to each other, and (b) shows a horizontal roll of a UF mill in which a UR mill, a UE mill and a UF mill are arranged close to each other. Fig. 1 shows a line for producing H-section steel using variable width rolls. Fig. 3 (c) shows a UR mill and a UE mill placed close to each other. Figure showing line for manufacturing H-section steel using variable width rolls as horizontal rolls, (d) shows UR mill, UE mill and UF mill placed close to each other, and variable width between horizontal rolls of UE mill and UF mill FIG. 3 is a diagram showing a line for manufacturing an H-section steel using rolls. Here, “disposed close to” means a state in which a table roll does not exist between two stands and these stands are arranged continuously.

I · To make the horizontal roll width of the universal edger mill (U E mill) smaller than the horizontal roll width of the UNIVA coarse mill (UR mill):

FIG. 6 is a front view of each roll of the UE mill used in the rolling method of the present invention, a longitudinal sectional view showing the shape of the rolled material, and a diagram showing the positional relationship between them. This UE mill is a universal type having an upper edge yah horizontal roll 12, a lower edge yah horizontal roll 13, and vertical rolls 14 and 15.

The roll width L of the horizontal rolls 12 and 13 of the UE mill should be smaller than the width of the horizontal roll of the UR mill in the previous process, and the gap between the body inclined portion 21 of the horizontal roll and the inner surface 22 of the rolled material flange The space 16 of ά is provided, and the horizontal surface of the rolled material is not restrained by the horizontal roll. The vertical rolls 14 and 15 restrain the flange outer surface 23, and the horizontal rolls lower the flange tip 7.

If the roll does not restrain the inner surface of the rolled material flange but only the outer surface, it can prevent the flange from buckling outward when the flange is pressed down in the width direction, and buckling occurs as shown in Fig. 4. The effect of correcting the center deviation of the web is improved. In addition, by providing a space between the horizontal roll and the inner surface of the flange of the rolled material, the height of the web is reduced in the final pass of the UE mill, and the web height is different. Can be manufactured with the same UE mill.

For example, the UE mill shown in Fig. 6 is placed on the UE mill on the line shown in Fig. 5 (a). A description will be given of the case in which this is done.

In Fig. 5 (a), a continuous green slab or bloom of the material is heated to about 1250 ° C in a heating furnace (not shown), then rolled by a 2 Hi-BD mill, and the raw material of H-section steel ( Beam blank). Next, it is rolled or straightened to predetermined dimensions by reciprocating rolling (intermediate rolling) of 7 to 15 passes by a universal mill group (UT) consisting of a UR mill and a UE mill, and finally, an H-shape of the target dimensions is produced by a UF mill. Finish to steel.

For example, a case where an H-shaped steel of H700 X B200 is manufactured will be described. When the horizontal roll of the UR mill has a roll width L of 676 for H700 X B200, and the horizontal roll of the UE mill uses a smaller roll of 566 faces, the roll of H600 X B200 to H700 x H-beams up to B200 can be manufactured. In this case, a space (5 ^ 50 sleep) will be provided between the horizontal roll of the UE mill and the inner surface of the rolled material flange, so that the flange does not buckle and the web center is not biased. Steel can be manufactured. Further, when the UR mill and the UE mill are arranged close to each other, an H-section steel having excellent dimensional accuracy at the front and rear ends in the longitudinal direction of the rolled material can be obtained.

I. Placement of a universal finishing mill (UF mill) in close proximity As shown in Fig. 5 (b), the above UE mill, which has a space between the horizontal roll and the inner surface of the rolled material flange, is placed close to the UR mill. Further, by disposing the UF mill in close proximity, the dimensional accuracy of the leading end and the trailing end in the longitudinal direction of the rolled material can be improved. Also, since the UF mill can be used for intermediate rolling, rolling in the thickness direction can be performed twice in one bath of the UR mill and the UF mill, and the rolling efficiency is lower than the method shown in Fig. 5 (a). Is improved by about 50% or more. Furthermore, the length of the rolling line can be reduced, and the length of the building of the rolling building can be shortened. I. Regarding the variable width of the horizontal roll of the universal finishing mill (UF mill):

Fig. 7 (a) is a diagram showing the roll width of the UE mill shown in Fig. 6, and Fig. 7 (b) is a front view and rolled material of each roll of a universal finishing mill (UF mill) with a variable width in the horizontal mouth. FIG. Reference numeral 17 denotes a two-part horizontal roll of variable width, and reference numeral 18 denotes a vertical roll.

If a UF mill using a variable width roll as the horizontal roll shown in FIG. 7 (b) is arranged close to the UE mill as shown in FIG. 5 (b), for example, the following rolling can be performed.

As shown in Fig. 7 (a), if the horizontal roll width of the UR mill is 676 (equivalent to the internal dimensions of the web, for H700 XB200) and the horizontal roll width of the UE mill is 566 mm, then the horizontal roll width of the UF mill is If the width of the steel is variable from 676 mm to 576 mm, three types of H-sections, H700 X B200, H650 x B200 and H600 x B200, can be rolled. In other words, the UR mill and UF mill perform reduction in the thickness direction of the web and flange of the rolled material, the UE mill performs reduction in the flange width direction, and the final pass of the UE mill reduces the rib height by 50IM. Further, by changing the horizontal roll width from 676mm to 626mm in the final pass of UF mill, H-section of H650 XB 200 can be rolled. Similarly, if the height of the tube is reduced by 100I 1 in the final pass of the UE mill and the width of the horizontal opening is changed from 676 to 576 strokes in the final pass of the UF mill, an H600 x B200 H-section can be rolled. .

In the above, examples of H-section steel with different rib heights have been described.However, if a line for rolling H-section steels with different flange width, web thickness and flange thickness is used, the above method can be used to keep the outer dimension constant. H-section steel can be manufactured. Also, since the horizontal roll width of the UE mill is smaller than the horizontal roll width of the UR mill and the space is provided, no rolling mill for changing the web height is required. There is also an effect.

Using the mill configuration shown in Figs. 5 (a) and 5 (b) and applying the method of reducing the web height in the final pass of the UE mill in the method described in I and II above, the same roll can be used. The product that can be manufactured has the effect of further increasing the degree of freedom in the size of the H-section steel.

W. About the variable width of the horizontal roll of the Universal Edge Yar Mill (U E Mill):

Fig. 8 shows a front view of the variable width horizontal roll and vertical roll of the UE mill and a cross-sectional view of the rolled material. Since the width of such a variable width horizontal roll 19 can be changed on-line, the space 16 (the space existing in the fixed width horizontal roll, (See Fig. 6). Therefore, a hole shape is formed by the horizontal roll and the vertical roll of the UE mill, and the inner and outer surfaces of the flange can be restrained by the roll, and the tip of the flange can be lowered by the horizontal roll, so that the dimensional accuracy can be further improved. In addition, when producing multi-size H-section steel, the number of horizontal rolls of the UE mill can be reduced, and the time required to change rolling rolls can be reduced. In addition, it will be more suitable as a line for manufacturing H-section steel with constant outer dimensions with high dimensional accuracy. When a UE mill equipped with a variable width horizontal roll as shown in Fig. 8 is used for the line as shown in Fig. 5 (c), the end of the flange, the inner surface and the outer surface can be constrained by the roll in the UE mill. The effect of correcting the center deviation of the web and the effect of correcting the fluctuation of the flange width are increased over the entire length of the product, making it possible to manufacture H-beams with high dimensional accuracy.

In addition, when used in a line as shown in Fig. 5 (d), in addition to the above dimensional accuracy improvement, the rolling efficiency can be improved by about 50% as described earlier with reference to Fig. 5 (b). .

As shown in Fig. 2, the roll for a normal 2 Hi-E mill For several types of edge pier holes, for example, when the roll body length is 2500 mm, three rolls of the ezja hole for (A): for H500X200, (B): for H550X200, and (C): for H600x200 as described above. It is engraved on.

For example, in the case of a double-type edger mill as shown in Fig. 3 (b), if the horizontal roll width is constant, it is necessary to have different horizontal rolls for each product size. . However, if the horizontal roll width can be changed up to a maximum of 100mm, one type of variable width roll, for example, H600X200,

Rolling of three sizes of H550X200 and H500X200 becomes possible, and the number of rolls held is equal to the rolls for 2 Hi-E mills shown in Fig. 2 where a large number of holes are engraved.

The roll for a 2 Hi-E mill with a 2500 mm long body weighs 20 tons or more, but the weight of a universal horizontal roll is only about 7 tons, and the price is 2 Hi-E even if a variable width mechanism is adopted. This is about 2/3 of the mill roll.

In order to make the width of the roll variable, for example, as shown in Japanese Utility Model Laid-Open Publication No. 3-111404 (US Pat. No. 5,154,074, European Patent No. 443725), a protrusion is provided on the outer peripheral surface of the movable sleeve roll, and the width of the movable sleeve roll is reduced. A male screw is formed at the base end of the sleeve with a key, and the protrusions provided at equal positions on the nut screwed to this male screw are fitted into the protrusion gaps of the movable sleeve roll. May be fixed in the axial direction with a split key.

In addition, as described above, intermediate rolling was performed by a group of mills using a UE mill with a variable horizontal roll width, and subsequent finishing rolling was arranged close to the group of mills as described in I above. H-beams can also be manufactured using UF mills. Further, an H-section steel can also be manufactured using a universal mill having a horizontal roll having a variable width as described in the above [5] as the UF mill.

A UE mill with a variable horizontal roll width can also roll multi-size H-sections with high dimensional accuracy. The effects of the method for manufacturing an H-section steel according to the present invention will be described based on Preliminary Tests 1 and 2, Examples 1 to 6, and Comparative Examples.

(Preliminary test 1)

The effect of correcting the center deviation of the web center when the horizontal roll width of the UE mill is smaller than the horizontal roll width of the UR mill and the inner surface of the flange of the rolled material is not restrained by the horizontal roll of the UE mill using a model mill. Confirmed. FIG. 9 is a view showing a vertical cross-sectional shape of a rolled crude material used in a model mill. Stainless steel that does not generate scale at the rolling temperature was used as the rolled raw material so that the finished rolled dimensions could be measured accurately (0.1 stroke units). Rolled raw material is pre-centered in the web

_{[(Bi - b 2) / 2} = (. 23. 5-21 5) / 2 = 1 ] is such that 1 mm, were prepared by cutting from the length 500mm stainless steel.

Rolling temperature was 900 ° C, number of passes was 1 and flange width reduction was 6%.

The following three types were used as edge yard mills.

① 2 Hi hole type; horizontal roll contacts the inner surface of flange, horizontal roll width is 84mm

②Universal type; horizontal and vertical rolls restrain the inner and outer surfaces of the flange, horizontal roll width is 84mm

(The method described in "WALZWERKSWESENJ" described in the section of the prior art)

(3) Universal type: A horizontal roll width of 64 mm and a space width of 5 = 10 mm between the inner surface of the flange and the horizontal roll. After the above-described rolling, the thickness of the web and the flange portion was further reduced by a horizontal roll with a variable width type UF mill at a reduction rate of 1%, and the center deviation of the web was measured.

Fig. 10 shows the longitudinal center of the rolled material and the rolled material obtained in the above test. It is a figure showing a measured value of bias.

In FIG. 10, the solid line indicated by (D) is the case where the roll is rolled using the edge-mill type II double-hole type roll, and the flange portion (b, = 23.5 drawing) buckles outward, Since there was no edging and only the original UF mill returned to its original state, there was almost no effect of correcting the center deviation, and it was almost the same as that shown by the solid line (G) in (G). In addition, in FIG. 10, the chain line indicated by (E) is the case where the roll is rolled using a universal edger mill of the edge yard type II, and the lobe moves about l mm toward the center of the flange. It was improved from 1 band to 0.01 stroke. Further, in FIG. 10, the solid line indicated by (F) indicates that when the method of the present invention described in (3) above is used, the flange is prevented from buckling outward, so that the web is directed toward the center of the flange. It can be seen that it has moved about one distance, the center deviation has been improved from 1 mm to 0.02 mm, and the same effect as when using the edge yard mill (2) (chain line (E)) is obtained.

(Preliminary test 2)

A test was carried out in which the height of the web was changed using the ezja mill type (3) used in Preliminary Test 1 and the rolled rough material shown in FIG.

The web height was reduced by 12 mm from 100 mm to 88 mm, and the flange width was reduced by 3 from 50 mm to 47 strokes, and then passed through a UF mill as in Preliminary Test 1. FIG. 6 is a diagram illustrating a change in the length direction of flange radiance measured before and after passing through a UF mill. In the figure, the broken line (H) shows the change in the flange width after rolling on the UE mill, and the solid line (J) shows the change in the flange width after rolling on the UF mill. As shown in the figure, even if the rib height is reduced, the fluctuation of the flange width is small, and the flange width after UF mill rolling is 47.09 to 46.79πιπι (fluctuation range ± 0.3%). Excellent dimensional accuracy of (± 1.5%) or more can be secured. this This is because, when the web height is reduced, the flange tip is also lowered, so that the metal flow from the web portion accompanying the web height reduction occurs in the rolling direction and does not change the flange width.

(Example 1)

A UE mill as shown in Fig. 6 was placed on the mill line shown in Fig. 5 (a). The horizontal roll of the U E mill is a roll for H800 X B300, and the roll width (L) is 750mm. Using this device, web height 900 mm, flange width 300 mm, web thickness 12 mm, flange thickness 25 mm (hereinafter referred to as “900 XB 300 xl2 / 25”) and H850 x B300 x 12 / A test was conducted to produce three types of H-section steel, H25X and H800XB300x1225. In the mill line in Fig. 5 (a), the distance between the UR mill and the UE mill was 3m, and the distance between the UE mill and the UF mill was 120m.

First, when manufacturing the H900 XB 300, the UR mill and UF mill have a horizontal opening width of 850 mm, two UR mills and a UE mill perform seven passes of tandem reverse rolling, and finally one pass of the UF mill. To H900 XB 300. At this time, in the UE mill, there is a space <5 between the inner surface of the rolled material flange and the horizontal roll, which is about 50 hidden.

Next, when manufacturing the H850 XB 300, the horizontal width of the UR mill and UF mill is 800 mm, and the two UR and UE mills perform tandem reverse rolling of 7 mm and finally UF mill. H850 x B300 was completed in one pass of the mill. At this time, in the UE mill, there is a space <5 of about 25 between the inner surface of the flange of the rolled material and the horizontal roll.

When manufacturing the H800 X B300, the UR mill and UF mill have a horizontal width of 750 mm, and two UR and UE mills perform tandem reverse rolling of 7 passes, and finally, one pass of the UF mill. To H800 x B300. At this time, in the UE mill, there is no space 3 between the inner surface of the flange of the rolled material and the horizontal roll. As described above, since a roll having a width smaller than the horizontal roll width of the UR mill was used as the horizontal roll of the UE mill, a single UE mill, such as H900 XB 300, H850 x B 300, and H800 x B 300, was used. Various types of H-section steel were manufactured.

Fig. 12 is a diagram showing the dimensional accuracy of the various H-sections obtained in Examples (1 to 6) and the manufacturing tolerances of the hot-rolled H-sections and the welded H-sections. The dimensional accuracy of the obtained H-section steel was sufficient for the manufacturing tolerances of the welded H-section steel.

(Example 2)

Using the equipment with the mill line configuration shown in Fig. 5 (a), a horizontal roll (width: 850 images) for H900 x B300 is used for the UR mill, and a horizontal roll (width (L) for H800 x B300) is used for the UE mill. 750 mm) and a horizontal roll (width: 800 mm) for H850 x B300 in a UF mill, and a test was conducted to produce an H-section steel of H850 x B300 x 1225. Assuming that the space section 5 of the UE mill is 50, the UR mill and the UE mill are used to perform 6-bus evening demembours rolling.

It was intermediate-rolled to a rough shape for H900XB300. Then, in the 7th pass of the UE mill, the height of the tube was reduced by 50 times to form a shape for the H850XB300, and the H-beam of H850XB300x12Z25 was finished in one pass of the UF mill.

As described above, by rolling the UE 5 while keeping the space 5 constant, the web height can be easily reduced in the final pass of the UE mill, and the dimensions of the obtained H-section steel can be reduced. As shown in Fig. 12, the accuracy was dimensional accuracy that was well within the manufacturing tolerances of the welded H-section steel.

(Example 3)

Using the mill line configuration shown in Fig. 5 (b), a horizontal roll (roll width 850 mm) for H900 x B300 is used for the UR mill, and a horizontal roll (roll width 750 mm) for H800 x B300 is used for the UE mill. ), H850x for UF mill A horizontal roll (fixed roll having a roll width of 800 mm) of a roll for B300 was incorporated into each of them, and a test was conducted to manufacture an H-shaped H850 XB 300 x 1225. In the mill line in Fig. 5 (b), the distance between the UR mill, the UE mill and the UF mill was 3 m.

First, in the reciprocating rolling from 1 pass to 6 passes, the UF mill pass was set as an empty pass that does not perform rolling, and the space 5 of the UE mill was set to 50 strokes and reciprocated rolling was performed between the UR mill and the UE mill. Intermediate rolling to a shape for use. Next, the web height was reduced by 50 mm in the 7th pass of the UE mill to form a shape for H850 x B300, and the H-shaped steel of H850 X B300 x 12/25 was finished in one pass of the UF mill.

In this way, by rolling the UF mill as an empty pass while keeping the space 5 constant in the UE mill, the web height can be easily reduced and reduced in the final pass of the UE mill. Since the two mills were arranged close to each other, the dimensional accuracy of the obtained H-section steel was superior to that of Example 2 as shown in FIG.

(Example 4)

A test was conducted to produce H850XB300X12 / 25 H-section steels using a horizontal roll that can change the roll width in the range of 750 to 850 mm for the UF mill of the mill line shown in Fig. 5 (b). Was. With the horizontal roll width of the UF mill set to 850 mm, five passes of tandem reverse rolling were performed using three mills, the UR mill and the UE mill. In the initial four-pass rolling, the UF mill was used as an empty pass, and H900 X B300 was rolled using the UR mill and UE mill. In the 5th pass, the height of the web was reduced by 50 in the UE mill and rolled into a shape for the H850 XB 300, and the horizontal roll width of the UF mill was reduced to 800 strokes and the H850 x B 300 X 12Z25 Finished in H-section steel. The dimensional accuracy of the obtained H-section steel was better than that of Example 3 as shown in FIG.

Easily reduce and reduce web height in the final pass of the UE mill By reducing the width of the flat roll and constraining the flange to finish rolling

As shown in FIG. 12, excellent dimensional accuracy was obtained.

(Example 5)

Three types of H-section steels of H500 × B200 × 10/16, H550 × B200 × 10/16 and H600 × B200 × 1016 were rolled using the mill line shown in FIG. 5 (d). The distance between the UR mill, the UE mill and the UF mill should be 3 m.

For the rolled material, for example, in the case of H500 X B200, a continuous structure slab having a thickness of 300 mm and a width of 700 mm was used.

Fig. 14 is a diagram showing the pass schedule for rolling the H-section steel in a 2Hi breakdown mill (2Hi-BD mill). After heating to 1250 ° C in a heating furnace, using a 2 Hi-BD mill with the hole arrangement shown in Fig. 13, the web schedule is 720 mm according to the pass schedule shown in Fig. 14. Web thickness 60 mm, flange A beam blank (coarse material of H-section steel) with a width of 250 mm and an average flange thickness of 110 mm was formed.

As shown in FIG. 8, the UE mill having a variable width horizontal roll used in this embodiment has a vertical roll with a width of 190 hiding the convex portion in contact with the outer surface of the flange, and a horizontal roll with a hole depth d. 93.5 The roll width was set to 468 mm when the distance D between the left and right sleeve rolls 19 'was 0 mm. This interval D can be changed offline or online as described above.

H550 X B200 Χ When rolling an H-section steel of 10/6, D is set to 50 and horizontal roll width L is 518 hidden, and for H600 B200 X10-16, 100 rolls are used for horizontal rolls. The width L was 568 mm. However, in consideration of the wear of the UR mill horizontal roll, the structure can be changed up to 120 times.

FIG. 15 is a diagram showing a pass schedule when the H shape is rolled along the line shown in FIG. 5 (d). The horizontal roll width of the UR mill is 468 mm, UE at this time The horizontal roll width of the mill was set to 468 mm, which was the same as the former, and an H-section steel of H500 X B200 X 10/16 was manufactured using the pass schedule shown in Fig. 15.

In the UE mill, the vertical roll does not reduce the flange portion in the thickness direction, and has the same opening as the thickness of the rolled material entrance side. In other words, the main purpose of the vertical roll is to prevent the flange from buckling due to the reduction in the flange width of the horizontal roll and to suppress the wall thickness increase at the center of the flange. In order to reduce the flange width reduction in the UE mill to 5% or less, the reduction ratio in the thickness direction of the flange and web in the UR mill was adjusted between 1.5: 1.0 and 2.0: 1.0. Finally, the H-shaped steel of the target size was manufactured by one-pass light rolling in the UF mill. Also, the horizontal roll width of the UR mill was set to 518, the horizontal width of the UE mill and UF mill was increased by 518, and H-section steel of H550 X B200 x 10 16 was manufactured. The horizontal roll width was 568 mm, and the horizontal roll width of the UE mill and UF mill was increased to 568 mm to produce H600 x B200 x 10/16 H-section steel. Figure 12 shows the dimensional change of each part of the obtained H-section steel.

In this way, the UE mill and UF mill use variable width horizontal rolls, and the UE mill and UF mill reduce the flange while restraining the flange.As shown in Fig. 12, excellent dimensions equivalent to welded H-section steel are shown in Fig. 12. Accuracy was obtained.

(Example 6)

Three types of H-section steel, H500 X B200, H550 x B200, and H600 X B200, were rolled using the mill line shown in Fig. 5 (c). In the mill line of Fig. 5 (c), the distance between the UR mill and the UE mill was 3 m, and the distance between the UE mill and the UF mill was 120 m.

For the UR mill and the UE mill, the same horizontal rolls for the UR mill and the UE mill as in Example 5 were used, and for rolling three types of H-section steel, the UF mill used horizontal rolls dedicated to each size.

In the case of H600 X B200, the horizontal roll width of UR mill, UE mill and UF mill is 568 mm, and the pressure of both UE mill and UF mill is No reduction in the web height of the rolled material was performed.

In the case of H550 X B200, the horizontal roll width of the UE mill is reduced from 568 mm to 518 in the final pass of the UR mill and UE mill group of the above H600 x B200 rolling, where the web height of the rolled material is obtained. Was reduced by 50 and finished rolled in a UF mill.

The same applies to the case of H500 X B200.The horizontal roll width of the UE mill was reduced from 568 mm to 468 strokes in the final pass of the UR mill and UE mill group for the above H600 x B200 rolling, where the web height of the rolled material was determined. The height was reduced by 100 mm and finish rolling was performed using a UF mill. Figure 12 shows the dimensional change of each part of the obtained H-section steel.

(Comparative example)

FIG. 16 is a view showing a roll arrangement of a conventional 2 Hi-E mill and a longitudinal section of a rolled material.

FIG. 17 is a diagram showing a pass schedule when a conventional 2 Hi-E mill is used as an edge yard mill of the mill line of FIG. 5 (d) as a comparative example and an H-section steel is rolled. The conventional 2 Hi-E mill with the depth d of 93.5 sq. Of the single-hole type shown in Fig. 16 was placed on the ezger mill of the mill line in Fig. 5 (d), and the H-section steel of H500 x B 200 x 10Z16 was drawn. It was manufactured according to the pass schedule shown in FIG. H600 X B200 X 10/16 H-section steel was manufactured in the same manner. Figure 12 shows the dimensional changes of each part of the obtained H-section steel.

As described above, in the conventional method in which the two Hi-E mills are arranged, the dimensional variation of each part of the H-section steel is large, and a method that satisfies the dimensional tolerance standard of the welded H-section steel cannot be obtained. In addition, the width of the flanges at the front and rear of the rolled material increased, and the manufacturing tolerances for welded H-section steel were out of tolerance.

FIG. 18 is a diagram showing a change in the web center deviation of the H500 × B200 × 1016 H-section steel obtained in Example 5 and Comparative Example in the rolling direction. In the figure, the solid line (K) indicates the line shown in Fig. 5 (d). The dashed line (M) indicates the case where the conventional 2Hi-E mill is arranged and the dashed line (M) is the case where it is manufactured with three universal mills arranged in close proximity.

From Fig. 18, the part where the center deviation S is more than ± 2 mra (manufacturing tolerance of welded H-section steel) is about 30% or more of the pressure elongation in the conventional method, but is 0% in the method of the present invention. It is important to be able to eliminate defects due to center deviation.

This is because, when rolling with a universal mill, the front and rear ends of the rolled material do not elongate in the rolling direction in the longitudinal direction, so the flange width tends to be larger than that in the center. This is corrected by rolling down the tip of the flange with an Etzger mill for each reciprocating rolling pass.However, with a 2Hi-E mill as shown in Fig. 16, it is possible to correct the rolling down just by buckling the flange. It is impossible to do so, and it will only be restored by the next UR mill rolling, and it will be extremely difficult to correct the center deviation.

On the other hand, as shown in Fig. 8, buckling can be prevented by restraining both sides of the rolled material flange with both vertical rolls of the UE mill and rolling down the flange tip. In addition, since the flange central portion is preferentially deformed as the flange width is reduced and stretched in the rolling direction, the flange width at the front and rear ends in the longitudinal direction of the rolled material is equal to the central flange width. it can.

According to the hot rolling method of the H-section steel of the present invention, the dimensional accuracy is improved and the center deviation of the web can be reduced as compared with the case where the conventional 2Hi edge yarn is used. H-section steel with dimensional accuracy comparable to that of section steel can be manufactured. In addition, since the height of the web can be changed during rolling, a plurality of H-section steels having different sizes with a dimensional accuracy comparable to that of the welded H-section steel can be manufactured with one set of mills. Industrial applicability

According to the method for manufacturing an H-section steel of the present invention, a conventional 2 Hi edge mill is used. Dimensional accuracy is improved compared to when used, and ゥ center deviation can be reduced. Moreover, since the height of the web can be easily reduced during rolling,

One group of mills can produce multi-size H-sections by hot rolling with dimensional accuracy comparable to that of welded H-sections.

It can be used for high-mix, low-volume production of H-section steel, which is required for building steel frames.

Claims

The scope of the claims

1. A method for producing an H-section steel, wherein a mill group in which a universal rough mill and a universal edge yard mill each composed of four rolls are arranged close to each other is used in at least a final stage of an intermediate rolling process, The width of the horizontal roll is made smaller than the width of the horizontal roll of the universal coarse mill, and the outer surface of the flange of the crude material is constrained by the vertical roll of the universal edger mill, and the horizontal roll rolls down the tip of the flange. This is a method of manufacturing H-section steel.

2. A method for rolling an H-section steel, wherein a mill group in which a universal rough mill and a universal edger mill each including four rolls are arranged in close proximity to each other in at least the final stage of the intermediate rolling process, The width of the horizontal roll of the Ezger Mill is made smaller than the width of the horizontal roll of the Universal Rough Mill, the outer surface of the flange of the coarse material is restrained by the vertical roll of the Universal Ezja 1 Mill, and the horizontal roll rolls down the tip of the flange. A method for rolling an H-section steel, comprising: performing intermediate rolling; and performing subsequent finishing rolling using a universal finishing mill disposed close to the mill group.

3. The method for producing an H-section steel according to claim 2, wherein a universal mill having a variable width horizontal roll is used as the universal finishing mill.

4. A method for rolling an H-section steel, in which a group of mills each having a four-roll universal coarse mill and a universal edge yard mill disposed in close proximity to each other is used at least in the final stage of the intermediate rolling process. The width of the horizontal roll of the mill is variable, a hole is formed by the horizontal roll and the vertical roll of the universal edger mill, the inner and outer surfaces of the flange are restrained by rolls, and the tip of the flange is lowered by the horizontal roll. A method for producing an H-section steel.

5. A method for rolling H-shaped steel using a mill group in which a universal rough mill and a universal edge yard mill each consisting of four rolls are arranged in close proximity to at least the final stage of the intermediate rolling process, comprising: Intermediate rolling in which the width of the horizontal roll of the mill is variable, the horizontal roll and the vertical roll of the Universal Ezger Mill form a hole, the inner and outer surfaces of the flange are bound by rolls, and the tip of the flange is lowered by horizontal rolls And a subsequent finish rolling is performed using a universal finishing mill arranged in close proximity to the mill group.

6. The method for producing an H-section steel according to claim 5, wherein a universal mill having a variable width horizontal roll is used as the universal finishing mill.

7. The method for producing an H-section steel according to any one of claims 1 to 6, wherein the height of the web is reduced in the final pass of the universal esger mill in the intermediate rolling step.