JP2010149181A - Process for producing t-bar steel and series of rolling devices - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing T-bar steel and series of rolling devices. <P>SOLUTION: The process for producing T-bar steel includes an intermediate rolling step in which the web and the flange of the T-shaped steel bar roughly formed into a T-shape are rolled, and a finishing step in which the T-shaped steel bar obtained in the intermediate rolling step is finish-rolled into the shape of a product. The intermediate rolling step comprises: a rolling step using a first universal roughing mill, wherein upper and lower horizontal rolls reduce the entire upper and lower surfaces of the web in the thickness direction; an edger rolling step in which the edge faces of the flange are reduced; and a rolling step using a second universal roughing mill, wherein upper and lower horizontal rolls, each having a roll outer circumferential surface that is the same width as the intended inner height of the web and also having a corner which is located on the web-tip side and has been processed into a shape that does not roll the web surface, are used to reduce the upper and lower sides of the web in the thickness direction, excluding an area near the tip, and simultaneously with this rolling, one of right and left vertical rolls is used to reduce the edge face of the web in the height direction of the web, while keeping the outer circumference of the vertical roll in contact with the horizontal rolls, and the other vertical roll is used to reduce the flange in the thickness direction thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a T-section steel by hot rolling and a rolling equipment row.

  FIG. 12 shows the cross-sectional shape of the T-section steel. The T-section steel 10 is a section having a T-shaped cross section composed of a web 11 and a flange 12, and is widely used in fields such as shipbuilding and bridges. Products with various dimensions are available depending on the application, usage conditions, location, etc. It is manufactured.

  The dimensions of the T-shaped steel usually used are as follows: web height: about 200-1000 mm, web thickness: about 8-25 mm, internal web dimension: about 190-980 mm, flange width: about 80-300 mm, flange thickness: 12- It is about 40 mm. Furthermore, in the case of a T-shaped steel used for shipbuilding, the web height is often more than twice the flange width.

  Further, even when the web height and the flange width are substantially the same, a plurality of sizes of T-shaped steel having different web thicknesses and flange thicknesses are selected according to the required strength and applied to the structure. As shown in FIG. 13, the web internal dimension Ai and the web external dimension Ao (same as the web height in FIG. 12) may be used as the web height reference. The case where the legal dimension Ai is the same is referred to as constant in-web method, and the case where the external dimension Ao is the same is referred to as constant external method. When the in-web method is constant, as shown in FIG. 13A, when the flange thickness tf changes to tf1, tf2, and tf3, Ai is constant and Ao changes to Ao1, Ao2, and Ao3. When the outer web method is constant, as shown in FIG. 13B, when the flange thickness tf changes to tf1, tf2, and tf3, Ao is constant and Ai changes to Ai1, Ai2, and Ai3. When T-shaped steels having different sizes are connected in the length direction, the inner surface of the flange (surface on the web side) becomes the same height when the inner web method is constant, and a step is generated on the outer surface of the flange. On the contrary, when the outer web method is constant, the flange has the same height as the outer surface of the flange when connected in the length direction, resulting in a step on the inner surface. Which one is used is selected from the viewpoint of workability according to the application and use site.

  By the way, the T-shaped steel is generally manufactured by welding the web 11 and the flange 12, but a technique for integrally forming the T-shaped steel by rolling has also been proposed.

  For example, in order to efficiently produce T-shaped steels with various web thicknesses, flange thicknesses, web heights and flange widths, a hot rolling facility in which one universal rolling mill is arranged in each of the intermediate rolling process and the finishing rolling process. Has been proposed (for example, Patent Document 1).

  FIG. 14 shows an example, and a rough shaping rolling mill 1 that reciprocally rolls a raw steel piece carried out from a heating furnace (not shown) to roughly form a cross-section into a substantially T-shaped section, and the rough shaping rolling mill 1 A rough universal rolling machine 2 for forming a T-shaped steel piece (not shown) roughly formed into a T-shape into a T-shaped steel having a substantially product size, and an edger rolling machine 3 disposed downstream of the rough universal rolling machine 2 And a finishing universal rolling mill 5 (FIG. 14A).

  The rolling process by the rough universal rolling mill 2 and the edger rolling mill 3 is an intermediate rolling process, and the rolling process by the finishing universal rolling mill 5 is a finishing rolling process. FIG. 14B shows the configuration of the rough universal rolling mill 2 as shown in FIG. FIG. 14C schematically shows the configuration of the edger rolling mill 3, and FIG. 14D schematically shows the configuration of the finishing universal rolling mill 5.

  The rough universal rolling mill 2 has horizontal rolls 21a and 21b and culm rolls 22a and 22b, and the finishing universal rolling mill 5 has horizontal rolls 51a and 51b and culm rolls 52a and 52b. Therefore, it is possible to roll into products having various flange thicknesses and web thicknesses without adjusting the rolls by adjusting the respective roll opening degrees.

  The edger rolling mill 3 has edger rolls 31a and 31b, which are composed of a large diameter portion 33 and a small diameter portion 32, and the end surface of the flange 12 can be pressed down by the small diameter portion 32 to adjust the flange width.

  Patent Document 2 discloses a method for efficiently producing T-shaped steel using a triaxial roughing mill and a triaxial edger. After rough rolling, the end surface 11a of the web 11 and the end surface 12a of the flange 12 are simultaneously reduced by the triaxial edger shown in FIG.

  Furthermore, in Patent Document 3, when performing reciprocating rolling with at least two universal rolling mills arranged in tandem on a rough shaped steel piece of T-shaped steel formed by roughly rolling a steel piece, FIG. As shown, the web and flange of the rough steel slab are reduced in the thickness direction by one universal rolling mill UR, and the flange of the rough steel slab is reduced in the width direction by the other universal rolling mill UF, or A method of manufacturing a hot-rolled T-section steel is disclosed in which the reduction in the width direction of the flange and the reduction in the height direction of the web are simultaneously performed.

  Further, Patent Document 3 discloses that at least one rough universal rolling mill UR and at least one two 2 arranged adjacent to a rough shape steel piece of T-shaped steel formed by performing rough rolling on a steel piece. While performing reciprocating rolling with a heavy rolling mill E, the coarse universal rolling mill performs the reduction of the web thickness and flange thickness of the rough shaped steel slab and the adjustment of the web height of the rough shaped steel slab, After forming the T-shaped steel by performing intermediate rolling in which the reduction of the flange width of the rough shaped steel slab and the reduction of the thickness of the end of the web is performed by a double rolling mill, the finished universal rolling mill UF is used to A technique for manufacturing a T-shaped steel by performing finish rolling for adjusting at least one of the thickness, the thickness of the web, or the height of the web is disclosed (FIG. 17).

Japanese Patent Publication No. 43-19671 Japanese Unexamined Patent Publication No. 57-4301 JP 2007-331027 A

  When rolling with the rolling equipment shown in FIG. 14, in the rough universal rolling mill 2 in the intermediate rolling process, the web 11 of the T-shaped billet (rolled material) H is crushed in the plate thickness direction by the horizontal rolls 21a and 21b. At the same time, the flange 12 of the T-shaped billet H is pressed down in the plate thickness direction between the scissors roll 22a and the horizontal rolls 21a and 21b.

  The side roll 22b that does not roll down the flange 12 is disposed in contact with the side surfaces of the horizontal rolls 21a and 21b, and when the flange 12 is rolled down, a thrust force acting in the axial direction of the horizontal rolls 21a and 21b from the side roll 22a. The horizontal rolls 21a and 21b are pressed against their side surfaces so as not to move.

  Further, in the edger rolling mill 3 provided close to the downstream of the rough universal rolling mill 2, the end face in the width direction of the flange 12 of the T-shaped slab H is pressed down to adjust the width of the flange 12. In the finish rolling process, the flange 12 is shaped vertically between the horizontal rolls 51a and 51b and the scissors rolls 52a and 52b by the finish universal rolling mill 5, and the web is not squeezed down in the height direction, and the T-section steel is used. The hot rolling is finished.

  That is, when the rolling equipment shown in FIG. 14 is used, the web thickness and the flange thickness are adjusted using the rough universal rolling mill 2 in the intermediate rolling process, and further, the flange end face is rolled down by the edger rolling mill 3 and the flange is moved. Although the width is adjusted, the web is not rolled down by the roll in the height direction.

  For this reason, the height of the web may not necessarily be the target dimension, and the web tip (the end surface 11a of the web 11 in FIG. 12) has a cross-sectional shape (a cross-sectional shape perpendicular to the longitudinal direction of the product, and so on). Is not preferable as a product shape.

  There is also a measure to cut the web tip with a gas cutter or slitter after hot rolling to make a product, but in this case, a cutting process is added after hot rolling, so the manufacturing cost of T-section steel Increase in production time and production period (such as delay in delivery).

  Patent Document 1 describes that a cutting portion is provided in a horizontal roll of a finishing universal rolling mill and a web end portion is cut and shaped in a finishing rolling process. A product with good shape cannot be obtained.

  In the method disclosed in Patent Document 2 in which the end surface 11a of the web 11 and the end surface 12a of the flange 12 are simultaneously reduced by the triaxial edger, the web height is also adjusted.

  However, since only the end face of the web 11 is constrained during edger rolling, when the web height is large or when manufacturing a T-shaped steel having a small web thickness, a strong reduction is applied to the web end face. If it tries to go, the web 11 will buckle and the web height cannot be adjusted with high precision. In particular, in shipbuilding T-shaped steel having a web height that is twice or more the flange width, there is a problem that the accuracy of the web height is likely to be buckled.

  On the other hand, in the rolling method described in Patent Document 3, the web is pressed down in the height direction by the roll of the second universal rolling mill shown in FIG. Can be adjusted.

  However, although the universal rolling mill plays a role of simultaneously reducing the flange width and the web tip, the thickness reduction ratio of the web and the flange must be as small as several percent. This is because the flange width is reduced by using a step-shaped horizontal roll having a small diameter part and a large diameter part, so it is necessary to use a saddle roll having a small diameter part on the flange side. This is to cause a step difference in the flange thickness. Further, by reducing the flange width, the thickness of the flange tip increases, so that the step of the flange thickness is further increased, and the possibility that surface defects such as folds on the flange outer surface will occur increases.

  Due to the structural problems of the second universal rolling mill as described above, although there are two universal rolling mills, the thickness is substantially reduced by only one universal rolling mill. There is a problem that increases.

  In the second universal rolling mill shown in FIG. 16, the rolling reaction force caused by one of the saddle rolls rolling down the flange acts in the axial direction of the horizontal roll. Since it is not in contact with the side surface, the axial load of the horizontal roll cannot be supported by the heel roll. That is, when trying to effectively reduce the flange thickness, it is difficult to support an axial load of several thousand kN acting on the horizontal roll, and therefore the flange reduction rate cannot be increased.

  Furthermore, since the inclination angle of the flange in intermediate rolling is preferably 5 degrees or less, when the second universal rolling mill is used to effectively reduce the flange thickness, the contact length between the flange inner surface and the horizontal roll side surface is long. Therefore, there is also a problem that the flange inner surface is easily wrinkled by the sliding of the roll and the rolled material.

  On the other hand, in another method using the rough universal rolling mill and the double rolling mill described in Patent Document 3 shown in FIG. 17, since there is one rough universal rolling mill, the number of rolling passes is large, and the angle of the flange is set. Since 0 degree or more and 5 degrees or less are desirable, there exists a problem that a wrinkle is easy to be attached to the flange inner surface.

  The present invention has been made to solve the above-described problems, and the shape of the web tip is good, the desired web height can be obtained with high accuracy, and the T-shaped steel is efficiently manufactured with a small number of passes. An object of the present invention is to provide a manufacturing method and a rolling equipment train for the purpose.

The object of the present invention can be achieved by the following means.
1. An intermediate rolling step of rolling a web and a flange of a T-shaped steel piece roughly formed into a T-shape, and a finish rolling step of performing finish rolling to make the T-shaped steel piece obtained in the intermediate rolling step into a product shape; A method for producing a T-section steel having
The intermediate rolling step includes a rolling step by a first rough universal rolling mill in which upper and lower horizontal rolls reduce the entire upper and lower surfaces in the web thickness direction,
An edger rolling process for rolling down the end face of the flange;
A plate where the width of the roll outer peripheral surface is the same as the target internal web dimension, and the web is removed from the vicinity of the tip using the upper and lower horizontal rolls that are processed into a shape in which the corner on the tip of the web does not roll the web surface. While rolling down the upper and lower surfaces in the thickness direction, one of the left and right heel rolls squeezes the flange in the plate thickness direction, while the other brings the outer surface of the heel roll into contact with the horizontal roll and the web end face in the web height direction. And a rolling process using a second rough universal rolling mill that is rolled down to a T-shaped steel.
2. In the rolling process by the second rough universal rolling mill, by adjusting the opening degree of the other roll roll and the horizontal roll side face while bringing the outer peripheral surface of the roll roll that reduces the web end face into contact with the horizontal roll, 2. The method for producing a T-section steel according to 1, wherein a plurality of sizes of T-section steel having different in-web dimensions and different flange thicknesses are produced.
3. A T-section rolling equipment row for rolling a web and a flange with a T-shaped steel piece roughly formed into a T-shape as a material to be rolled,
A first rough universal rolling mill having upper and lower horizontal rolls whose width of the outer peripheral surface of the roll is wider than a target in-web dimension of the material to be rolled; an edger rolling machine for rolling down the end face of the flange of the material to be rolled; Upper and lower horizontal rolls whose outer peripheral surface width is the same as the target in-web dimension of the material to be rolled and the corner portion on the front end side of the web is processed into a shape that does not roll the web surface, and one of them rolls down the flange in the plate thickness direction. And a second rough universal rolling mill having left and right reed rolls that press the end face of the web in the height direction of the web while the other outer surface is in contact with the horizontal roll. T-steel rolling equipment line.

According to the T-section steel manufacturing method and rolling equipment row according to the present invention, the following effects can keep hot rolling, the web tip shape is good, and the desired web height can be accurately obtained. An effective method for producing a shape steel and a rolling equipment line are obtained, which are extremely useful in industry.
1. Since the reduction of the web thickness and the flange thickness in the intermediate rolling process is performed by both the first and second rough universal rolling mills, compared to the case of rolling the thickness by one rough universal rolling mill, per pass It is possible to increase the reduction amount of the web thickness and the flange thickness, thereby reducing the rolling pass and improving the rolling efficiency. Moreover, the rolling efficiency can be further improved by arranging a plurality of at least one of the first rough universal rolling mill, the edger rolling mill, and the second rough universal rolling mill.
2. With the second rough universal rolling mill, the outer periphery of the roll is brought into contact with the side (web tip side) that does not reduce the flange thickness of the horizontal roll, and the rolling reaction force acting in the axial direction of the horizontal roll due to the reduction of the flange thickness is By supporting and rolling down the end face of the web in the height direction, it is possible to prevent the horizontal roll from moving in the axial direction and to roll a T-shaped steel with good dimensional accuracy.
3. Since the corner portion on the web tip side of the horizontal roll used in the second rough universal rolling mill is processed into a shape that does not roll the web surface, no ear-shaped projections are formed even if the web tip is rolled down. A good web tip shape can be obtained.

The figure which shows an example of arrangement | positioning of the rolling equipment of T-section steel used for implementation of this invention. It is a figure explaining the structure of the 1st rough universal rolling mill used for implementation of this invention, (a) is the example, (b) is a schematic diagram explaining another example. The schematic diagram explaining an example of a structure of an edger rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of the 2nd rough universal rolling mill used for implementation of this invention. The schematic diagram explaining an example of a structure of a finishing universal rolling mill used for implementation of this invention. The schematic diagram explaining the protrusion shape generate | occur | produced in the rolling material web front-end | tip. Sectional drawing which shows the cross-sectional shape of T-section steel. It is a figure which shows the dimensional shape of the inner method constant and outer method constant T shape steel, (a) is inner method constant, (b) is a figure which shows T method steel with outer method constant. (A) is a layout diagram showing a conventional T-shaped steel rolling facility, (b) is a diagram for explaining the configuration of a rough universal rolling mill, (c) is a diagram for explaining the configuration of an edger rolling mill, (d) FIG. 3 is a diagram for explaining the configuration of a finishing universal rolling mill. The figure which shows the structure of the conventional edger rolling mill of T-shaped steel. It is a figure which shows the structure of the universal rolling mill in the rolling method of the conventional T-section steel, (a) is a figure which shows the structure of a 1st universal rolling mill, (b) is a figure which shows the structure of a 2nd universal rolling mill. . The figure which shows the rolling method of the conventional T-section steel using a rough universal rolling mill, an edger rolling mill, and a finishing universal rolling mill.

  Hereinafter, embodiments of a manufacturing method and a rolling equipment line according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an example of a rolling equipment line according to the present invention, in which 1 is a rough shaping rolling mill, 2 is a first rough universal rolling mill, 3 is an edger rolling mill, and 4 is a second rough universal rolling mill. Reference numeral 5 denotes a finish rolling mill.

  A raw steel slab (not shown) carried out of a heating furnace (not shown) is rolled into a T-shaped steel slab having a substantially T-shaped cross section by the rough shaping rolling mill 1. As the rough shaping rolling mill 1, known equipment can be used, for example, a double rolling mill equipped with a roll having a hole shape.

  The obtained T-shaped slab is rolled in a rolling equipment row in which the first rough universal rolling mill 2, the edger rolling mill 3 and the second rough universal rolling mill 4 are arranged close to each other, and a web and a flange Is reduced (intermediate rolling process).

  The schematic diagram explaining the structure of the 1st rough universal rolling mill 2 is shown to Fig.2 (a). The first rough universal rolling mill 2 includes horizontal rolls 21a and 21b that rotate on a horizontal axis, and roll rolls 22a and 22b that rotate on a vertical axis. The horizontal rolls 21a and 21b and the scissors rolls 22a and 22b are opposed to each other.

  In the present invention, the width (width of the pressed surface) W1 of the outer peripheral surface of the horizontal rolls 21a and 21b is made larger than the target inner dimension L of the web 11 (the distance from the flange inner surface to the web tip). Preferably, it is about 105 to 150% of the target internal dimension L of the web 11.

  In the first rough universal rolling mill 2, the entire surface in the height direction of the web 11 is squeezed in the plate thickness direction by the horizontal rolls 21a and 21b, and the flange 12 is formed on the side surfaces of the roll 22a and the horizontal rolls 21a and 21b. Roll down in the thickness direction.

  The thickness of the web 11 is adjusted by adjusting the opening of the horizontal rolls 21a and 21b, and the thickness of the flange 12 is adjusted by adjusting the opening of the flange roll 22a and the side surfaces of the horizontal rolls 21a and 21b.

  When the flange 12 is crushed, a thrust force acts in the axial direction from one side surface of the horizontal rolls 21a and 21b by the side roll 22a, so that the side roll 22b is pressed against the other side surface of the horizontal rolls 21a and 21b. The horizontal rolls 21a and 21b are preferably prevented from moving in the axial direction. Moreover, as shown in FIG.2 (b), the side surface of the scissors roll 22b and the horizontal roll pressed by this is good also as a perpendicular | vertical shape without an inclination.

  FIG. 3 is a schematic diagram for explaining the structure of the edger rolling mill 3. The edger rolling mill 3 has edger rolls 31a and 31b each having a large diameter roll portion 33 and a small diameter roll portion 32 in the horizontal axis direction. The large diameter roll portion 33 guides the web 11 of the material H to be rolled, and the small diameter roll. The roll surface 32a of the part 32 presses down the end surface 12a of the flange 12 in the width direction.

  The roll diameter of the large diameter roll section 33 and the roll diameter of the small diameter roll section 32 are such that the roll surface of the large diameter roll section 33 is in the thickness direction of the web 11 during rolling of the end face 12a of the flange 12 by the small diameter roll section 32. It is preferable to adjust so that there is a slight gap between the upper and lower surfaces.

  By providing a slight gap, an excessive rolling reaction force generated when the large-diameter roll portion 33 comes into contact with the web is eliminated, and the large-diameter roll portion 33 acts as a guide from the upper and lower web surfaces to the upper and lower flange tips. The effect of aligning the length up to is born, and the dimensional accuracy can be improved. The gap is preferably 2 mm or less.

  FIG. 4 is a schematic diagram illustrating the structure of the second rough universal rolling mill 4. 5 to 9 are also schematic diagrams for explaining other examples of the structure of the second rough universal rolling mill 4. The second rough universal rolling mill 4 has horizontal rolls 41a and 41b that rotate on the horizontal axis, and heel rolls 42a and 42b that rotate on the vertical axis. The horizontal rolls 41a and 41b and the heel rolls 42a and 42b are arranged to face each other.

  In the 2nd rough universal rolling mill 4, the roll opening degree of the horizontal rolls 41a and 41b is adjusted, the plate | board thickness of the web 11 is adjusted, and the opening degree of the side roll 42a and one side surface of the horizontal rolls 41a and 41b Is adjusted to adjust the plate thickness of the flange 12. At this time, the circumferential surface c of the eaves roll 42b is arranged in contact with the other side face b of the horizontal rolls 41a and 41b so that the horizontal rolls 41a and 41b do not move in the axial direction.

  The width (width of the pressed surface) W2 of the roll outer peripheral surface of the horizontal rolls 41a and 41b is substantially the same value as the target inner dimension L (distance from the flange inner surface to the end surface 11a of the web tip) in the intermediate rolling process of the web 11. (That is, W2 <W1). Note that the target internal dimension L of the web 11 in the intermediate rolling process is usually determined by taking into account the slight increase in web height in the finishing universal rolling mill, which is the final rolling process, and is usually used in the T-section steel in the product stage. It is preferable to make the value shorter by about 0 to 5 mm than the dimension. That is, it is preferable that the width W2 of the circumferential pressure surfaces of the horizontal rolls 41a and 41b is a value smaller by about 0 to 5 mm than the in-web dimension of the T-shaped steel product.

  Since the widths of the horizontal rolls 41 a and 41 b are the same as the target internal dimension L of the web 11, the scissors roll 42 b comes into contact with the tip of the web 11 and is pressed down to adjust the height of the web 11 and the shape of the end surface 11 a. It becomes possible.

  Furthermore, in the present invention, the corner portion a on the web tip side of the horizontal rolls 41a and 41b is subjected to curved surface processing, chamfering, or a step.

  In general, corner portions of upper and lower horizontal rolls incorporated in a rough universal rolling mill of a shape steel having a flange such as an H-shape steel are subjected to arc processing according to the product shape of the shape steel to be rolled. However, in rolling T-shaped steel, it is desirable to form the web tip at a right angle. From the viewpoint of adjusting to the same product dimensions as in the prior art, it is considered that arc processing is not necessary for the corner portion on the web tip side. However, when the tip of the web is crushed by the roll 42b, deformation occurs in which the volume of the crushed portion increases the web thickness within the cross section. And when there is no space in the corner portion, the deformation of the squeezed web tip flows into a slight gap between the peripheral surface c of the heel roll 42b and the other side face b of the horizontal rolls 41a and 41b, as shown in FIG. In addition, an ear-like protrusion 15 is formed at the tip of the web, and a defect such as a folding flaw is generated by rolling with a finishing universal rolling mill.

  In order to avoid this, in the present invention, the horizontal roll corner portion is processed and rolled into a shape that does not roll the web surface. Thereby, since a large space is formed between the circumferential direction pressure lower surface of the horizontal rolls 41a and 41b in the vicinity of the tip of the web 11 and the circumferential surface of the scissors roll 42b, a slight amount is generated when the end surface 11a of the web is rolled down. A local deformation (protrusion 15) is prevented from being formed in the gap.

  Specifically, the shape of the corner part a of the horizontal rolls 41a and 41b is arcuate processing (FIGS. 4 and 7), chamfering processing (FIGS. 5 and 8), or step processing (FIGS. 6 and 9). The space which does not roll the deformation | transformation part of the web surface of the web thickness direction of the web by the thickness increase of the web front-end | tip is ensured. When providing chamfers or steps, it is preferable to round the corners.

  Usually, the arc radius is 20 mm or more in the case of arc processing, and C20 or more processing is performed in the case of chamfering, thereby preventing the occurrence of the ear-like projections. In the case of step processing, the width of the step portion is preferably 20 mm or more. On the other hand, the upper limit of the processing dimension is preferably such that a web surface of 70% or more of the target internal dimension L in the intermediate rolling process of the web 11 is rolled. That is, it is preferable to make it within 30% with respect to the width W2 of the roll outer peripheral surface of the horizontal rolls 41a and 41b. Thus, when the end surface of the web 11 is rolled in the height direction of the web by the roll 42b, most of the web 11 (that is, other than the vicinity of the tip) is rolled in the thickness direction of the web by the horizontal rolls 41a and 41b. Therefore, the web 11 does not buckle even if the end surface 11a of the web front end portion is squeezed down by the heel roll 42b.

  In addition, when a horizontal roll corner part is made into the shape which does not roll a web surface, the web edge part side of a horizontal roll forms opening larger than web thickness. The opening width d of this opening is preferably about (web thickness + 10 mm) to (web thickness + 200 mm). More preferably, it is about (web thickness + 10 mm) to (web thickness + 100 mm). Also in shapes other than the above, it is preferable that the width of the non-rolled portion is 30% of 20 mm to L, and d is in the above range.

  The side b close to the web tip of the horizontal roll 41a (41b) is vertical as shown in FIGS. 4, 5 and 6, and preferably has the same inclination as the side on the flange side as shown in FIGS. An angle θ from the vertical may be 5 <θ ≦ 10 °.

  In the case of providing an inclination, an inclination of the same angle is also provided on the outer periphery of the reed roll 42b according to the inclination angle, and a vertically symmetrical mountain shape having an inclined hypotenuse with the center in the width direction of the roll surface as the apex is provided. However, a flat end having a width larger than the web thickness of the material H to be rolled is provided at the center in the width direction of the roll surface that rolls down the web tip.

  In the intermediate rolling process by the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 described above, reciprocal rolling is performed until a shape capable of finish rolling is obtained. In the first and second rough universal rolling mills, it is preferable to perform rolling such that the reduction ratio of the web thickness and the flange thickness is 10 to 30%. However, rolling with a rolling reduction of 10% or less may be performed in a specific pass such as the final rolling mill that finishes the intermediate rolling, or the rolled material may be passed without rolling.

  In addition, when the web 11 is rolled in the sheet thickness direction by the second rough universal rolling mill 4, a sheet thickness difference is generated between a portion that is crushed by the horizontal rolls 41a and 41b and a portion that is not crushed (near the web tip portion 11a). Sometimes. During the reciprocating rolling, the thickness of the web tip is reduced by the first rough universal rolling mill 2 to eliminate the difference in sheet thickness. Therefore, there is no problem even if the difference in sheet thickness occurs in the second rough universal rolling mill. Although there is a concern that harmful surface wrinkles such as wrinkles may occur at the boundary of the plate thickness difference during reciprocating rolling, in the study by the present inventors, surface wrinkles occur within the range of a web thickness reduction rate of 30% or less. I did not.

  However, when the second rough universal rolling mill is the last rolling mill that finishes the intermediate rolling, the web rolling reduction in the finishing universal rolling mill 5 in the next process is small. The resulting step may not be flattened by a finishing mill.

  If the difference in sheet thickness is so large that it cannot be eliminated by finishing rolling by the finishing universal rolling mill 5, the material to be rolled H is fed back and rolled again by the first rough universal rolling mill 2, and the web This can be eliminated by reducing the entire surface in the height direction. On the other hand, when the thickness difference is such that it can be eliminated by finish rolling by the finish rolling mill 5, the intermediate rolling process is finished as it is, and the finish rolling process is started. In addition, the roll opening degree of the second rough universal rolling mill 4 may be made larger than the dimension of the material to be rolled H in the final rolling pass of the intermediate rolling process, and may be passed without rolling. No difference in plate thickness occurs near the web tip.

  In the intermediate rolling step, the crossing angle α between the flange and the web is preferably 95 <α ≦ 110 °, more preferably 95 <α ≦ 100 °, in a cross-sectional view of the material to be rolled as viewed from the rolling direction. Is more preferable. By setting the crossing angle, it is possible to prevent the horizontal roll and the inner surface of the flange to be rolled from coming off quickly after rolling and generating wrinkles on the inner surface of the flange. In addition, the amount of roll refurbishment during roll wear can be reduced, and the roll life can be extended.

  When the crossing angle α between the flange and the web is 95 <α ≦ 100 °, in the rough universal rolling mills 2 and 4, the side surface of the horizontal rolls 21 and 41 on the side where the flange is pressed down is angle θ from the vertical direction: 5 Tilt so that <θ ≦ 10 °.

  The present invention is not limited to the arrangement shown in FIG. 1, and may be any other equipment as long as it has one or more first rough universal rolling mills 2, edger rolling mills 3, and second rough universal rolling mills 4. Any arrangement of can be applied.

  For example, at least one of the first rough universal rolling mill, the edger rolling mill, and the second rough universal rolling mill may be continuously arranged.

  Further, the arrangement order of the first rough universal rolling mill, the edger rolling mill, and the second rough universal rolling mill is changed, for example, the edger rolling mill and the second rough universal rolling mill are arranged at the beginning of the intermediate rolling process. May be. Furthermore, since each rolling mill is normally capable of reverse rolling or through (passing the rolling mill without rolling), the rolling order does not have to coincide with the rolling mill order.

  The T-shaped steel obtained in the intermediate rolling process is rolled to the product dimensions in the finish rolling process.

  In FIG. 10, the schematic diagram explaining the structure of a finishing universal rolling mill is shown. The finishing universal rolling mill 5 has horizontal rolls 51a and 51b that rotate on a horizontal axis and saddle rolls 52a and 52b that rotate on a vertical axis, and the side surfaces of the horizontal rolls 51a and 51b are orthogonal to the outer peripheral surface of the roll.

  In the finish rolling process, the rolled material in which the crossing angle α between the flange and the web is larger than 90 ° in the intermediate rolling process in the previous step is formed so that the crossing angle between the flange and the web becomes 90 °. When the flange of the material to be rolled H is rolled with the roll 52a having a flat outer periphery, the flange is shaped perpendicular to the web. The thickness reduction ratio of the flange is preferably a slight reduction of several percent and at most 5%. At this time, the horizontal rolls 51a and 51b can be prevented from moving in the axial direction by pressing the scissors roll 52b against the side surface of the horizontal rolls 51a and 51b that does not face the flange.

  In the finishing universal rolling mill, the web is hardly reduced or is lightly reduced at a thickness reduction rate of several% to adjust the shape and dimensions. In particular, when a difference in sheet thickness occurs between the portion that is squeezed by the horizontal rolls 41a and 41b and the portion that is not squeezed (near the web tip portion 11a) by rolling in the second rough universal rolling mill 4. Lightly reduce the web to eliminate. In order to meet this purpose, the width of the pressed surface of the horizontal rolls 51a and 51b is made larger than the in-web dimension (and thus larger than W2). Preferably, it is about 105 to 150% of the internal dimension of the web 11.

  If the manufacturing method and rolling equipment row of the present invention described above are used, a plurality of sizes of T-shaped steel having the same internal dimensions and different flange thicknesses can be manufactured. As shown in FIG. 13A, the T-shaped steel having a constant internal dimension has a constant internal web dimension Ai even if the flange thickness tf changes.

  In the present invention, the plate thickness tf of the flange can be adjusted by adjusting the opening degree between the side roll 42a of the second rough universal rolling mill and one side surface of the horizontal rolls 41a and 41b. At this time, the circumferential surface c of the eaves roll 42b is arranged in contact with the other side face b of the horizontal rolls 41a and 41b so that the horizontal rolls 41a and 41b do not move in the axial direction. Here, since the width of the roll outer peripheral surface of the horizontal rolls 41a and 41b is the same as the internal web dimension, the internal web dimension Ai can be rolled to a constant dimension regardless of the flange thickness. A certain T-shaped steel can be easily manufactured.

  Using the rolling equipment shown in FIG. 1, a T-section steel having a target dimension of a web height of 300 mm, a flange width of 100 mm, a web thickness of 9 mm, and a flange thickness of 16 mm is rolled from a bloom having a rectangular cross section with a thickness of 250 mm and a width of 310 mm. did.

  The 1st rough universal rolling mill 2 used the structure shown to Fig.2 (a). The horizontal roll was 320 mm so that the width W1 of the squeezed surface was wider than the target web internal dimension L (283 mm), and the angle θ from the vertical direction of the side surface of the horizontal roll was 7 °.

  The left and right scissors rolls are arranged so as to be opposed to each other, and in the cross-sectional shape, a vertically symmetrical mountain shape having a hypotenuse inclined at an angle of 7 ° from the vertical with the center in the width direction of the roll surface as a vertex.

  In addition, among the left and right scissors rolls, the pressing force of the one that presses the side surface of the horizontal roll was adjusted so that the horizontal roll would not move in the horizontal axis direction by rolling the flange.

  The edger rolling mill 3 has a structure shown in FIG. The step between the large-diameter portion and the small-diameter portion of the edger roll was 44 mm, and the roll width was 500 mm or more for the large-diameter portion and 200 mm or more for the small-diameter portion. Further, the inclination angle of the step portion was set to 7 ° from the vertical.

  The 2nd rough universal rolling mill 4 used the structure shown in FIG. The roll shaft of the horizontal roll was not reinforced, and a general structure was used. The horizontal roll was 283 mm so that the width W2 of the pressed surface was the same as the web target internal dimension in the intermediate rolling process, and the side surface of the horizontal roll on the side where the flange was rolled was inclined by 7 ° from the vertical. Moreover, the size of the curved surface processing of the horizontal roll corner portion a was an arc shape having a radius of 30 mm (the web end side opening width d of the horizontal roll is the web thickness of the material to be rolled + about 60 mm).

  In addition, one of the scissors rolls that rolls the flange with the left and right scissors rolls has a vertically-symmetrical chevron shape having a hypotenuse inclined at an angle of 7 ° from the vertical with the center in the width direction of the roll surface in the cross-sectional shape. The other scissors roll that squeezes the tip in the height direction was a cylindrical shape with a flat roll surface.

  A finishing universal rolling mill 5 having the structure shown in FIG. 10 was used. The width of the horizontal roll was 320 mm.

  First, the bloom was rolled with a rough shaping rolling mill 1 (using a double rolling mill incorporating a perforated roll) to obtain a T-shaped steel piece having a substantially T-shaped cross section. The obtained T-shaped billet had a web thickness of 40 mm, a flange thickness of 75 mm, a web height of 365 mm, and a flange width of 130 mm.

  Subsequently, reciprocal rolling of 5 passes is performed by a rolling mill group in which the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 described above are arranged in this order, and the web and the flange are reduced. did. Table 1 shows the pass schedule of the intermediate rolling process.

  In the 2nd rough universal rolling mill 4, the web front-end | tip part was crushed in the web height direction using the roll, and the web height was adjusted. At this time, rolling was performed while supporting the axial load of the horizontal roll, with the scissors roll rolling down the web tip in contact with the horizontal roll side surface. Finally, the finish universal rolling mill 5 having a horizontal roll and a heel roll was rolled while applying light reduction to the flange to shape the inclination of the flange vertically. The web part was under light pressure.

  After hot rolling, the web height, flange width, web thickness, and flange thickness of the obtained T-shaped steel were measured. As a result, according to the present invention, the T-shaped steel satisfying the target dimension was heated. It was confirmed that it could be produced as it was rolled.

  In particular, the web height, which was difficult to adjust with the conventional rolling, can be hot-rolled within the range of the target value ± 1 mm, and the end face shape was also good.

  Further, using the same rolling equipment, a constant inner T-shaped steel having an inner dimension equal to the flange thickness of 16 mm and a flange thickness of 19 mm was manufactured. The dimensions of the T-shaped steel slab after the raw steel slab having the same cross-sectional dimension as that of the flange thickness of 16 mm was rolled by the rough shaping rolling mill 1 were a web thickness of 33 mm, a flange thickness of 75 mm, a web height of 365 mm, and a flange width of 123 mm. It was.

  Subsequently, reciprocal rolling of 5 passes was performed by a rolling mill group in which the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 were arranged close to each other in this order, thereby reducing the web and the flange. Table 2 shows the pass schedule of the intermediate rolling process.

  In the 2nd rough universal rolling mill 4, the web front-end | tip part was crushed in the web height direction using the roll, and the web height was adjusted. At this time, as in the case of the flange thickness of 16 mm, the scissors roll that squeezes the web tip was brought into contact with the side surface of the horizontal roll, and rolled while supporting the axial load of the horizontal roll. Finally, the finish universal rolling mill 5 having a horizontal roll and a heel roll was rolled while applying light reduction to the flange to shape the inclination of the flange vertically. The web part was under light pressure.

  As for the dimensions of each part after hot rolling, a product having a target size such as a web height of 303 mm, a flange width of 100 mm, a web thickness of 9 mm, and a flange thickness of 19 mm was obtained. The in-web dimension was 284 mm and the same value as the product with a flange thickness of 16 mm.

  On the other hand, as a comparative example, an intermediate rolling process is performed using a conventional rolling facility (FIG. 14) composed of one rough universal rolling mill in which the width of the pressed surface of the horizontal roll is set wider than the web width and one edger rolling mill. T-shaped steel was manufactured. The bloom dimensions and target dimensions of each part after hot rolling of the T-shaped steel were the same as the flange thickness of 19 mm of the example of the present invention. Table 3 shows the pass schedule of the intermediate rolling process. Since there was only one rough universal rolling mill in the equipment of the comparative example, reciprocating rolling with 9 passes was performed to the target dimension.

  In the comparative example, since the tip of the web could not be crushed, the web height became larger than the target of 300 mm, and was about 306 mm, resulting in a dimension error. For this reason, it became necessary to cut the edge part of a web after rolling, and time and expense increased, and the manufacturing cost increased.

  In addition, since the number of passes increased, the rolling time of intermediate rolling increased to about twice as compared with the example of the present invention, and the productivity was greatly deteriorated.

  In the above examples using the pass schedules in Tables 1 and 2, the widths of the horizontal rolls of W1 and the finishing universal rolling mill were changed to 340 mm, respectively, but the results were also good.

  Furthermore, in the said Example, the shape of the corner part a of the horizontal roll of the 2nd rough universal rolling mill 4 is changed into the circular arc shape (FIG. 4) of radius 30mm (FIG. 5) (FIG. 5) (d = The results were also good when the web thickness was rolled as a step processing (FIG. 6) (d = web thickness + 30 mm) between the width of the web roll +40 mm) and a width of 50 mm from the corner of the horizontal roll.

  Next, as a second embodiment of the present invention, from a bloom having a rectangular cross section with a thickness of 300 mm and a width of 620 mm using the rolling equipment shown in FIG. 1, a web height of 500 mm, a flange width of 150 mm, a web thickness of 12 mm, and a flange thickness A T-shaped steel having a target dimension of 22 mm was rolled.

  The 1st rough universal rolling mill 2 used the structure shown in FIG.2 (b). The horizontal roll was 530 mm so that the width W1 of the pressed surface was wider than the in-web dimension, and the angle θ from the vertical direction of the side surface of the horizontal roll was 7 °.

  The left and right scissors rolls are arranged so as to be opposed to each other, and in the cross-sectional shape, a vertically symmetrical mountain shape having a hypotenuse inclined at an angle of 7 ° from the vertical with the center in the width direction of the roll surface as a vertex. In addition, among the left and right scissors rolls, the pressing force of the one that presses the side surface of the horizontal roll was adjusted so that the horizontal roll would not move in the horizontal axis direction by rolling the flange.

  The edger rolling mill 3 has a structure shown in FIG. The step between the large diameter portion and the small diameter portion of the edger roll was 67 mm, and the roll width was 550 mm or more for the large diameter portion and 200 mm or more for the small diameter portion. Further, the inclination angle of the step portion was set to 7 ° from the vertical.

  The 2nd rough universal rolling mill 4 used the structure shown in FIG. The horizontal roll was 477 mm so that the width W2 of the pressed surface was the same as the web target internal dimension in the intermediate rolling process, and the side surface of the horizontal roll that pressed the flange was tilted by 7 ° from the vertical. Moreover, the size of the curved surface processing of the horizontal roll corner portion a was an arc shape with a radius of 30 mm (d = web thickness + 60 mm).

  In addition, one of the scissors rolls that rolls the flange with the left and right scissors rolls has a vertically-symmetrical chevron shape having a hypotenuse inclined at an angle of 7 ° from the vertical with the center in the width direction of the roll surface in the cross-sectional shape. The other scissors roll that squeezes the tip in the height direction was a cylindrical shape with a flat roll surface.

  A finishing universal rolling mill 5 having the structure shown in FIG. 10 was used. The width of the horizontal roll was 520 mm.

  First, the bloom was rolled into a T-shaped steel slab having a substantially T-shaped cross section by the rough shaping rolling mill 1. The obtained T-shaped billet had a web thickness of 50 mm, a flange thickness of 95 mm, a web height of 585 mm, and a flange width of 185 mm.

  Subsequently, the web and the flange were reduced by performing 5 passes of reciprocating rolling in a rolling mill group in which the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 described above were arranged in this order. . Table 4 shows the pass schedule of the intermediate rolling process.

  In the second rough universal rolling mill 4, rolling was performed in a state where the roll on the web tip side was pressed against the side surface of the horizontal roll, and the web tip was adjusted in the web height direction to adjust the web height. Finally, the inclination of the flange was vertically shaped by a finishing universal rolling mill 5 having a horizontal roll and a roll.

  After hot rolling, when the web height, flange width, web thickness and flange thickness of the obtained T-shaped steel were measured, the dimensions were as intended, and the web height was within the target value ± 1 mm. The end face shape was also good.

  As a comparative example, an intermediate rolling process was performed using a conventional rolling facility including a first universal rolling mill, an edger rolling mill, and a second universal rolling mill shown in FIG. . Table 5 shows the pass schedule of the intermediate rolling process. In the equipment of this comparative example, since the thickness of the web and the flange cannot be reduced by the second universal rolling mill, reciprocating rolling with 9 passes was performed to the target dimension. For this reason, compared with the Example of this invention, the rolling time of intermediate | middle rolling increased about twice, and productivity deteriorated significantly. The product dimensions were as planned and there were no problems.

  From the above results, the T-shaped steel of the present invention can be hot-rolled with a T-shaped steel having a good dimensional accuracy even with a large-sized T-shaped steel having a web height of 500 mm and a flange width of 150 mm. It could be manufactured as rolled, and it was confirmed that the rolling efficiency was significantly improved as compared with the conventional one.

DESCRIPTION OF SYMBOLS 1 Rough shaping rolling mill 2 1st rough universal rolling mill 3 Edger rolling mill 4 2nd rough universal rolling mill 5 Finishing universal rolling mill 10 T-section steel 11 Web 11a End surface (web)
12 flange 12a end face (flange)
15 Ear-shaped projections 21a, 21b Horizontal rolls 22a, 22b 竪 rolls 31a, 31b Edger rolls 32 Small diameter portions 32a Pressurized lower surface 33 Large diameter portions 41a, 41b Horizontal rolls 42a, 42b 竪 rolls 51a, 51b Horizontal rolls 52a, 52b 竪 rolls W1 Width of outer peripheral surface of horizontal roll of first rough universal rolling mill W2 Width of outer peripheral surface of horizontal roll of second coarse universal rolling mill L In-web dimension H Material to be rolled (T-section slab)
a Corner portion b Side surface c Peripheral surface d Opening width

Claims (3)

An intermediate rolling step of rolling a web and a flange of a T-shaped steel piece roughly formed into a T-shape, and a finish rolling step of performing finish rolling to make the T-shaped steel piece obtained in the intermediate rolling step into a product shape; A method for producing a T-section steel having
The intermediate rolling step includes a rolling step by a first rough universal rolling mill in which upper and lower horizontal rolls reduce the entire upper and lower surfaces in the web thickness direction,
An edger rolling process for rolling down the end face of the flange;
A plate where the width of the roll outer peripheral surface is the same as the target internal web dimension, and the web is removed from the vicinity of the tip portion using the upper and lower horizontal rolls that are processed into a shape in which the corner portion on the tip side of the web is not rolled. While rolling down the upper and lower surfaces in the thickness direction, one of the left and right heel rolls squeezes the flange in the plate thickness direction, while the other brings the outer surface of the heel roll into contact with the horizontal roll and the web end face in the web height direction. And a rolling process using a second rough universal rolling mill that is rolled down to a T-shaped steel.   In the rolling process by the second rough universal rolling mill, by adjusting the opening degree of the other roll roll and the horizontal roll side face while bringing the outer peripheral surface of the roll roll that reduces the web end face into contact with the horizontal roll, The method for producing a T-section steel according to claim 1, wherein a plurality of sizes of T-section steel having different in-web dimensions and different flange thicknesses are produced. A T-section rolling equipment row for rolling a web and a flange with a T-shaped steel piece roughly formed into a T-shape as a material to be rolled,
A first rough universal rolling mill having upper and lower horizontal rolls whose width of the outer peripheral surface of the roll is wider than a target in-web dimension of the material to be rolled; an edger rolling machine for rolling down the end face of the flange of the material to be rolled; Upper and lower horizontal rolls whose outer peripheral surface width is the same as the target in-web dimension of the material to be rolled and the corner portion on the front end side of the web is processed into a shape that does not roll the web surface, and one of them rolls down the flange in the plate thickness direction. And a second rough universal rolling mill having left and right reed rolls that press the end face of the web in the height direction of the web while the other outer surface is in contact with the horizontal roll. T-steel rolling equipment line.

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