JP4453771B2 - T-section steel manufacturing method and rolling equipment line - Google Patents

Description

  The present invention relates to a method for manufacturing a T-shaped steel by hot rolling and rolling equipment.

  FIG. 9 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 that is usually used are as follows: web height: about 200 to 1000 mm, web thickness: about 8 to 25 mm, internal web dimension: about 190 to 980 mm, flange width: about 80 to 400 mm, flange thickness: 12 to 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.

  Moreover, although it is common to manufacture by welding the web 11 and the flange 12, the technique of integrally forming T-shaped steel by rolling is also 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. 10 shows an example thereof, 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 is used. 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. 10A).

  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. FIG. 10C schematically shows the configuration of the edger rolling mill 3, and FIG. 10D 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 horizontal rolls 31a and 31b, which are constituted by a large diameter portion 33 and a small diameter portion 32, and the end surface of the flange 12 can be crushed by the small diameter portion 32 to adjust the flange width.

Patent Document 2 discloses a method for efficiently producing a 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.
Japanese Patent Publication No. 43-19671 Japanese Unexamined Patent Publication No. 57-4301

  When rolling with the rolling equipment shown in FIG. 10, in the rough universal rolling mill 2 in the intermediate rolling process, the web 11 of the T-shaped slab H is pressed down in the plate thickness direction by the horizontal rolls 21a and 21b, and the roll 22a And the horizontal rolls 21a and 21b, the flange 12 of the T-shaped billet H is pressed down in the plate thickness direction.

  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.

Moreover, in the edger rolling mill 3 installed near the downstream of the rough universal rolling mill 2,
The width of the flange 12 is adjusted by reducing the end face of the flange 12 in the width direction. 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. 10 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 to form the flange. 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 reach the target dimension, and the web tip (the end surface 11a of the web 11 in FIG. 9) has a cross-sectional shape (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 the end portion of the web 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.

  The present invention has been made to solve the above-described problems, and a method for producing a T-section steel that is hot-rolled, has a good web tip shape, and can accurately obtain a desired web height. It aims to provide rolling equipment.

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 finishing rolling step of performing a 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-shaped steel having
The intermediate rolling process includes a rolling process by a first rough universal rolling machine in which upper and lower horizontal rolls roll down the entire upper and lower surfaces in the web thickness direction, an edger rolling process in which the end face of the flange is rolled down, and upper and lower horizontal rolls. While the roll is rolling down the upper and lower surfaces in the plate thickness direction excluding the vicinity of the end of the web, one of the left and right heel rolls rolls down the web end surface in the web height direction, and the other is the flange in the plate thickness direction second and a rolling step using rough universal rolling mill, the finishing rolling step the method for producing a T-shaped steel, characterized by have a rolling process by the finishing universal rolling machine for rolling the.
2. A T-shaped steel rolling equipment row for rolling a web and a flange using a T-shaped steel piece roughly formed into a T-shape as a material to be rolled,
As an intermediate rolling step, a first rough universal rolling mill having upper and lower horizontal rolls whose roll surface width is wider than the in-web dimension of the material to be rolled, and 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 width of the roll surface is narrower than the in-web dimension of the material to be rolled, and one that reduces the flange in the plate thickness direction and the other that reduces the end surface of the web in the web height direction. a second coarse universal rolling machine are arranged with vertical rolls with Ri Na,
As the finish rolling step, rolling equipment rows of T shaped steel width of the roll surface is characterized Rukoto finish universal rolling mill, such are arranged with a wider upper and lower horizontal rolls from web in dimensions, of the material to be rolled.
3. A groove portion whose bottom is linear and whose width is larger than the web thickness is formed at the center in the height direction of the reed roll that rolls down the web end face of the second rough universal rolling mill in the web height direction. The rolling equipment row | line | column of T-section steel as described in 2 mentioned above.

  In the above, “the bottom is linear” refers to a groove having a flat bottom. That is, in the roll cross section including the roll center axis, it means that the bottom of the groove is substantially straight.

According to the method for manufacturing a T-section steel and a rolling equipment train according to the present invention, a web having a web height that satisfies the target value can be obtained while maintaining the hot rolling, the end shape being good, and after the hot rolling. There is no need to cut the web tip. Since the cutting process is not necessary, the manufacturing process can be shortened and the manufacturing cost can be reduced, which is extremely useful industrially.

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).

  FIG. 2 is a schematic diagram for explaining the structure of the first rough universal rolling mill 2. 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 W1 of the pressing surface of the horizontal rolls 21a and 21b is made larger than the internal 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 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.

  FIG. 3 is a schematic diagram for explaining the structure of the edger rolling mill 3. The edger rolling mill 3 has horizontal rolls 31a and 31b including a large diameter roll portion 33 and a small diameter roll portion 32 in the horizontal axis direction, and the large diameter roll portion 33 guides the web 11 of the material H to be rolled, and the small diameter The roll surface 32a of the roll 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. 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 present invention, the width W2 of the roll surface of the horizontal rolls 41a and 41b is made smaller than the internal dimension L of the web 11 (the distance from the flange inner surface to the web tip 11a) (that is, W2 <W1). Preferably, it is about 70 to 95% of the internal dimension L of the web 11. Furthermore, it is preferable to secure a difference between W1 and W2 of 30 mm or more. When the flange 12 of the material to be rolled H is pressed against the side surfaces of the horizontal rolls 41a and 41b, the web leading end portion 11a protrudes outward from the roll surface of the horizontal rolls 41a and 41b. It is possible to reduce in the vertical direction.

  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, and the height of the web 11 and the shape of the end are adjusted by adjusting the opening degree between the side roll 42 b and the other side of the horizontal rolls 41 a and 41 b.

  In the roll shape of FIG. 4, since the axial movement of the horizontal rolls 41a and 41b cannot be suppressed by the heel roll 42b on the web front end side, a mechanism for suppressing the horizontal movement is incorporated into the roll axis of the horizontal rolls 41a and 41b. There is a need. For example, a structure may be adopted in which a thrust ball bearing or a thrust roller bearing is incorporated in the roll shaft to receive an axial thrust load.

  Moreover, if the rolling load at the time of rolling the flange 12 of the to-be-rolled material H with the 2nd rough universal rolling mill 4 becomes large, the load of the horizontal direction added to the roll axis | shaft of the horizontal rolls 41a and 41b will also become large, and the horizontal roll 41a. In some cases, the mechanism for suppressing the horizontal movement of 41b becomes large and the facility cost becomes excessive.

  In order to solve this problem, as shown in FIG. 5 (a), in the second rough universal rolling mill 4, a groove 43 is provided at the center in the height direction of the heel roll 42b on the web tip side. preferable. That is, if the outer periphery of the scissors roll other than the groove 43 is in contact with the side surfaces of the horizontal rolls 41a and 41b, the axial movement of the horizontal rolls 41a and 41b can be suppressed without providing a special mechanism.

  The groove 43 has a straight shape with a vertical bottom, and its width a is larger than the web thickness of the material H to be rolled. Moreover, the depth of the groove part 43 is determined according to the web height of the T-section steel used as a product, and the width W2 of the roll surface of a horizontal roll. The shape of the horizontal rolls 41a and 41b at this time may be such that the side surface near the web tip is vertical as shown in FIG. 5 (a), and the side surface near the web tip is shown in FIG. 5 (b). It may have an inclination similarly to the side surface on the flange side. When it has an inclination, it is preferable to provide the inclination of the same angle also on the outer periphery of the reed roll 42b according to the inclination angle.

  In the method of the present invention in which the second rough universal rolling mill 4 is used to roll the end surface of the web 11 in the height direction of the web with the roll 42b, the horizontal rolls 41a and 41b are used for most of the web (i.e., the tip 11a). Since the web 11 is rolled in the thickness direction of the web, the web 11 does not buckle even if the web leading end portion 11a is strongly squeezed by the roll 42b.

  However, if the width of the horizontal rolls 41a and 41b is narrow, the unrolled portion of the web becomes long and buckling tends to occur. Therefore, the width of the roll surface is preferably at least 70% of the in-web dimension. On the other hand, in order to sufficiently secure the reduction margin of the web end surface, it is preferable to set the vicinity of the web end portion of 20 mm or more as the non-reduction region.

  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, reciprocating rolling is performed as necessary until a shape capable of finish rolling is obtained. Do.

  Further, when the web 11 is rolled in the plate thickness direction by the second rough universal rolling mill 4, a plate 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.

  When the plate thickness difference is so large that it cannot be eliminated by finish rolling by the finish 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 height direction of the web All that is necessary is to reduce the entire surface.

  If the plate thickness difference is such that it can be eliminated by finish rolling by the finish rolling mill 5, the intermediate rolling process is terminated and the finish rolling process is started. In the final rolling pass of the intermediate rolling process, the roll opening of the second rough universal rolling mill 4 may be made larger than the dimension of the material H to be rolled, and may be passed without rolling. There is no difference in plate thickness near the tip.

  In the intermediate rolling step, it is preferable that the crossing angle between the flange and the web is 95 to 100 ° in a cross-sectional view of the material to be rolled as viewed from the rolling direction. 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 between the flange and the web is 95 to 100 °, in the rough universal rolling mill, the side surface of the horizontal roll and the pressed surface of the roll are inclined so that the angle θ is 5 to 10 ° from the vertical direction (see FIG. 2). The scissors roll has a vertically symmetrical chevron shape having a hypotenuse inclined at an angle θ of 5 to 10 ° from the vertical with the center in the width direction of the roll surface in the cross-sectional shape (FIGS. 2, 4, and 5). The side of the horizontal roll and the side roll on the side where the flange is not crushed may be substantially θ = 0 ° (FIGS. 4 and 5A).

  In the present invention, since the intermediate rolling process is performed by the first and second rough universal rolling mills, the web thickness and the flange thickness per pass are reduced as compared with the case of rolling by one rough universal rolling mill. The amount can be increased, reducing the rolling pass and improving the rolling efficiency.

  In order to further improve the rolling efficiency, a plurality of at least one of the first rough universal rolling mill, the edger rolling mill, and the second rough universal rolling mill may be arranged.

  For example, as shown in FIGS. 7 and 8, a plurality of sets of configurations including the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 can be arranged. FIG. 7 shows a configuration in which two sets of configurations including the first rough universal rolling mill 2, the edger rolling mill 3, and the second rough universal rolling mill 4 are arranged. FIG. 8 shows a configuration in which three sets of the first rough universal rolling mill 2, the edger rolling mill 3 and the second rough universal rolling mill 4 are arranged, and the intermediate rolling process can be completed in one pass. It is possible and the rolling efficiency is dramatically improved.

  The present invention is not limited to the arrangement shown in FIGS. 1, 7, and 8, and has at least one first rough universal rolling mill 2, edger rolling mill 3, and second coarse universal rolling mill 4. Any other arrangement can be applied as long as it is a facility.

  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. 6, 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 roll 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 roll surface.

  When the flange of the material to be rolled H is rolled with the roll 52a, the flange is shaped perpendicular to the web. The horizontal rolls 51a and 52b 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 52b that does not face the flange.

  In the finishing universal rolling mill, the web is hardly reduced, or lightly reduced to adjust the shape and dimensions. 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 L of the web 11.

  The finishing universal rolling mill and the rough universal rolling mill are generally different in the shape of the flange roll. That is, in a rough universal rolling mill, it is often a mountain shape with θ: 3 to 15 °. On the other hand, in the finishing universal rolling mill, θ = 0 ° substantially. In any universal rolling mill, the rolling surface of the horizontal roll is substantially straight on the cross section including the central axis.

  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 thing of the structure shown in FIG. The horizontal roll was set to 320 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 set to 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 2nd rough universal rolling mill 4 used the structure shown in FIG. A thrust roller bearing is incorporated in the roll shaft of the horizontal roll to make it resistant to loads in the roll shaft direction. The horizontal roll was 250 mm so that the width W2 of the pressed surface was narrower than the in-web dimension, and the side surface of the horizontal roll on the side where the flange was rolled was tilted by 7 ° from the vertical.

  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.

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

  A finishing universal rolling mill 5 having the structure shown in FIG. 6 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 375 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.

  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. Finally, the inclination of the flange was vertically shaped by a finishing universal rolling mill 5 having a horizontal roll and a roll. 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.

  In addition, although the experiment which changes variously the width W2 of the pressing surface of the horizontal roll of the 2nd universal rolling mill 4 was also performed, if W2 is at least 70% with respect to the in-web normal dimension of the product, the web will buckle. It was possible to reduce in the height direction.

  On the other hand, as a comparative example, an intermediate rolling process is performed using a conventional rolling facility (FIG. 10) 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 the target dimensions of each part after hot rolling of the T-shaped steel were the same as those of the example of the present invention. 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 was doubled compared to the examples of the present invention, and the productivity was greatly deteriorated.

  In addition, in the said Example, although the width of the horizontal roll of W1 and a finishing universal rolling mill was changed to 340 mm, respectively, the result was also favorable.

  Next, as a second embodiment of the present invention, a rough universal rolling mill having slopes on both sides of the horizontal roll shown in FIG. 5B is used for the second rough universal rolling mill. A T-shaped steel having the same dimensions as in Example 1 was rolled.

  The rough shaping rolling mill 1, the first rough universal rolling mill 2, and the edger rolling mill 3 used the same equipment as in the first example. Since the horizontal roll bearing of the second rough universal rolling mill 4 is not a special bearing as in the first embodiment but a normal one, a facility cost can be saved.

  The horizontal roll was 250 mm so that the width W2 of the pressed surface was narrower than the in-web dimension, and the side surface of the horizontal roll on the side where the flange was rolled was tilted by 7 ° from the vertical. The scissors roll has a vertically symmetrical mountain shape with 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, and the scissors roll 42b on the web tip side has a depth from the scissors roll surface. A linear groove having a vertical bottom of 34 mm and a width of 100 mm was provided.

  In the manufacture of the T-shaped steel, first, a bloom having the same dimensions as in the first example was rolled by the rough shaping rolling mill 1 to obtain a T-shaped steel piece having a substantially T-shaped cross section. The dimensions of the obtained T-shaped slab were a web thickness of 40 mm, a flange thickness of 75 mm, a web height of 375 mm, and a flange width of 130 mm, as in the first example.

  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.

  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. From the above results, the T-shaped steel with a good dimensional accuracy is still hot-rolled with the T-shaped steel manufacturing method and rolling equipment using the second rough universal rolling mill shown in FIG. 5 (b) of the present invention. It was confirmed that it could be manufactured.

  Next, as a third embodiment of the present invention, in the rolling equipment shown in FIG. 1, a thickness of the rolling equipment row in which the first rough universal rolling machine 2 and the second rough universal rolling machine 4 are replaced is used. A T-section steel having a target dimension of a web height of 500 mm, a flange width of 150 mm, a web thickness of 12 mm, and a flange thickness of 22 mm was rolled from a bloom having a rectangular cross section with a thickness of 300 mm and a width of 620 mm.

  That is, in the intermediate rolling process in the third embodiment, the second rough universal rolling mill 4, the edger rolling mill 3, and the first rough universal rolling mill 2 are arranged in this order.

  The 2nd rough universal rolling mill 4 used the structure which has an inclination in the both sides | surfaces of the horizontal roll shown in FIG.5 (b). The horizontal roll was 440 mm so that the width W2 of the pressed surface was narrower than the in-web dimension, and the side surface of the horizontal roll was tilted by 7 ° from the vertical.

  The scissors roll has a vertically symmetrical mountain shape with 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, and the scissors roll 42b on the web tip side has a depth from the scissors roll surface. A linear groove having a bottom of 37 mm and a width of 100 mm was provided.

  The edger rolling mill 3 has a structure shown in FIG. The level difference between the large diameter part and the small diameter part of the horizontal roll was 68 mm, and the roll width was 550 mm or more for the large diameter part and 200 mm or more for the small diameter part. Further, the inclination angle of the step portion was set to 7 ° from the vertical.

  The 1st rough universal rolling mill 2 used the thing of the structure shown in FIG. 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.

  A finishing universal rolling mill 5 having the structure shown in FIG. 6 was used. The width of the horizontal roll was 520 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 50 mm, a flange thickness of 95 mm, a web height of 585 mm, and a flange width of 185 mm.

  Subsequently, the second coarse universal rolling mill 4, the edger rolling mill 3, and the first coarse universal rolling mill 2 described above are reciprocally rolled in five passes by a rolling mill group arranged close to each other in this order to reduce the web and the flange. did.

  In the second rough universal rolling mill 4, rolling was performed in a state where the roll at the web tip side was pressed against the side surface of the horizontal roll, and the web height was adjusted by reducing the web tip portion in the web height direction. Finally, the inclination of the flange was shaped vertically 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.

  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 was confirmed that the product could be produced as it was rolled.

The figure which shows an example of arrangement | positioning of the rolling equipment of T-section steel used for implementation of this invention. The schematic diagram explaining an example of a structure of the 1st rough universal rolling mill used for implementation of this invention. 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. (A), (b) is a schematic diagram explaining another 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 finishing universal rolling mill used for implementation of this invention. The figure which shows the other example of arrangement | positioning of the rolling equipment of T-section steel used for implementation of this invention. The figure which shows the other example of arrangement | positioning of the rolling equipment of T-section steel used for implementation of this invention. Sectional drawing which shows the cross-sectional shape of T-section steel. (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.

Explanation of symbols

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 11 Web 11a End surface (web front end)
12 Flange 12a End face of flange 21a, 21b Horizontal roll 22a, 22b Edge roll 31a, 31b Edger roll 32 Small diameter part 32a Pressurized surface 33 Large diameter part 41a, 41b Horizontal roll 42a, 42b Flat roll 43 Groove part 51a, 51b Horizontal roll 52a, 52b竪 Roll W1 Width of the rolling surface of the horizontal roll of the first rough universal rolling mill W2 Width of the rolling surface of the horizontal roll of the second rough universal rolling mill L In-web dimension H Rolled material

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 finishing rolling step of performing a 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-shaped steel having
The intermediate rolling process includes a rolling process by a first rough universal rolling mill in which upper and lower horizontal rolls roll down the entire upper and lower surfaces in the web thickness direction, an edger rolling process in which the end face of the flange is rolled down, and upper and lower horizontal rolls. While the roll is rolling down the upper and lower surfaces in the plate thickness direction excluding the vicinity of the end of the web, one of the left and right heel rolls rolls down the web end surface in the web height direction, and the other is the flange second and a rolling step using rough universal rolling mill, the finishing rolling step the method for producing a T-shaped steel, characterized by have a rolling process by the finishing universal rolling machine for rolling the. A T-shaped steel rolling equipment row for rolling a web and a flange using a T-shaped steel piece roughly formed into a T-shape as a material to be rolled,
As an intermediate rolling step, a first rough universal rolling mill having upper and lower horizontal rolls whose roll surface width is wider than the in-web dimension of the material to be rolled, and 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 width of the roll surface is narrower than the in-web dimension of the material to be rolled, and one that reduces the flange in the plate thickness direction and the other that reduces the end surface of the web in the web height direction. a second coarse universal rolling machine are arranged with vertical rolls with Ri Na,
As the finish rolling step, rolling equipment rows of T shaped steel width of the roll surface is characterized Rukoto finish universal rolling mill, such are arranged with a wider upper and lower horizontal rolls from web in dimensions, of the material to be rolled.   A groove portion whose bottom is linear and whose width is larger than the web thickness is formed at the center in the height direction of the scissors roll that rolls down the web end face of the second rough universal rolling mill in the web height direction. A rolling equipment row of T-section steel according to claim 2.

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