KR20140107446A - Method for manufacturing t-shaped steel and rolling equipment - Google Patents

Abstract

A method of manufacturing a T-shaped steel and a rolling apparatus which manufacture a T-shaped steel having a flange width different from each other without changing the rolls.
The present invention relates to a rough rolling process for roughly forming a T-shaped piece of a billet, an intermediate rolling process for pressing down a roughly formed T-shaped piece of steel by a universal mill and an edge mill, And the difference rf-rw between the flange reduction ratio rf and the web reduction ratio rw when the thickness of the web and the flange is reduced by the universal rolling mill in the intermediate rolling step is set as a reduction ratio difference, A rolling path is formed in at least one pass in the range of the reduction rate difference of 5 to 15% in the first half pass of the rolling process, and at the same time, the first plurality of passes including the first pass or the first pass , The T-shaped steel having a longer flange leg length than the flange leg length of the T-shaped steel piece is manufactured.

Description

METHOD FOR MANUFACTURING T-SHAPED STEEL AND ROLLING EQUIPMENT BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

TECHNICAL FIELD The present invention relates to a method of manufacturing a T-shaped steel by hot rolling and a rolling facility, and more particularly to the manufacture of T-shaped steel of a plurality of sizes having different flange widths from the same equipment.

Fig. 1 shows the cross-sectional shape of the T-shaped steel. The T-shaped section 10 is a section steel having a T-shaped cross section composed of a web 11 and a flange 12 and is widely used in the fields of shipbuilding and bridges. Various sizes of products are being manufactured.

The dimensions of the generally used T-shaped steel are as follows: the web height Hp is about 200 to 1000 mm, the web thickness twp is about 8 to 25 mm, and the inside dimension of the web (distance from the inner surface of the flange to the front end of the web) Mm, the flange width Bp is about 80 to 300 mm, and the flange thickness tfp is about 12 to 40 mm. In the case of a T-shaped steel used for shipbuilding, the height of the web is often more than twice the flange width.

Even if the web height and the flange width are almost the same, T-shaped steel of plural sizes different in web thickness and flange thickness is selected according to the required strength and applied to the structure. For this reason, there is a need for a technique for efficiently producing T-shaped steel having different thicknesses.

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

For example, in order to efficiently manufacture T-shaped steel having various dimensions of web thickness, flange thickness, web height and flange width, a technique of rolling a T-shaped steel using a universal rolling method used for manufacturing H-shaped steel has been disclosed (Patent Document 1).

Further, in order to produce a T-shaped steel having good dimensional accuracy in section, a technique has been developed in which two universal mills are placed close to each other and a web roll is rolled with a vertical roll of one universal mill (Patent Document 2). In addition, a hot rolling facility and a rolling method in which two universal rolling mills are arranged in the intermediate rolling process and one in the finishing rolling process have been proposed (for example, Patent Document 3).

3 shows an example thereof. In the drawing, reference numeral 1 denotes a roughing molding machine, 2 denotes a first rough universal mill, 3 denotes an edger mill, 4 denotes a second rough universal mill, 5 denotes a finish universal mill . A work piece (not shown) taken out of a heating furnace (not shown) is rolled by a rough milling mill 1 into a T-shaped section having a substantially T-shaped cross section.

The obtained T-shaped section is rolled in a row of rolling mills in which the first fundamental universal mill 2, the edge mill 3 and the second universal mill 4 are arranged in close proximity, (Intermediate rolling process).

As shown in Fig. 5, the first fundamental universal rolling mill 2 has horizontal rolls 21a and 21b rotating on a horizontal axis and vertical rolls 22a and 22b rotating on a vertical axis. In the example of Fig. 5, the width of the lower surface of the horizontal rolls 21a and 21b is made larger than the inner dimension of the web 11 (the distance from the flange inner surface to the web front end).

In the first fundamental universal rolling mill 2, the entire surface in the height direction of the web 11 is pressed down in the plate thickness direction by the horizontal rolls 21a and 21b and the vertical roll 22a and the horizontal rolls 21a, 21b of the flange 12 in the thickness direction.

6, the eger mill 3 has horizontal rolls 31a and 31b having a large-diameter portion 33 and a small-diameter portion 32 in the horizontal axis direction, The large-diameter portion 33 guides the web of the rolled material, and the roll surface of the small-diameter portion 32 presses the end face of the flange in the width direction thereof. The dimension HEe of the stepped portion between the large-diameter portion 33 and the small-diameter portion 32 is conventionally set so that the flange leg length of the T-shaped steel (the width of the flange 12 and the thickness of the web 11) 2), which is the same as or slightly smaller than the value obtained by the above-described method.

As shown in Fig. 7, the second fundamental universal rolling mill 4 has horizontal rolls 41a and 41b rotating on a horizontal axis and vertical rolls 42a and 42b rotating on a vertical axis. In the example of Fig. 7, the width of the roll surface of the horizontal rolls 41a and 41b is made smaller than the inner dimension of the web (the distance from the flange inner surface to the web front end). When the flange of the press-fitted strip is pushed to the side of the horizontal rolls 41a and 41b, the web front end protrudes outward beyond the rolls of the horizontal rolls 41a and 41b, .

In the second fundamental universal rolling mill 4, the roll gap of the horizontal rolls 41a and 41b is adjusted to adjust the plate thickness of the web, and the thickness of the web rolls 41a and 41b The height of the web and the shape of the end portion are adjusted by adjusting the opening degree between the vertical roll 42b and the other side surface of the horizontal rolls 41a and 41b do.

The T-section steel obtained in the intermediate rolling process is rolled to product dimensions in the finish rolling process. 8, the finishing universal rolling mill 5 has horizontal rolls 51a and 51b rotating on a horizontal axis and vertical rolls 52a and 52b rotating on a vertical axis. Horizontal rolls 51a and 51b, Is orthogonal to the roll surface. Rolling the flange of the pressurized strip with the vertical roll 52a causes the flange to be formed perpendicular to the web. At this time, the plate thickness of the flange and the web is preferably set to a light pressure lower than a few percent. The horizontal rolls 51a and 51b can be prevented from moving in the axial direction by pressing the vertical rolls 52b to the side surfaces of the horizontal rolls 51a and 51b that are not opposed to the flanges. In the example of Fig. 8, the lower surface of the horizontal rolls 51a and 51b has a larger width than the inner dimension of the web.

Japanese Patent Publication No. 43-19671 Japanese Laid-Open Patent Publication No. 2007-331027 Japanese Patent Publication No. 4544371

However, since T-shaped steel has various web heights and flange widths, it is highly necessary to produce T-shaped steel having different websheets or flange widths even when T-shaped steel is produced by hot rolling. However, in the conventional rolling method, in the case of producing a T-shaped steel in which the web height and the flange width are different, it is necessary to make the T-shaped steel piece to be rolled in the rough molding rolling process to a dimension matching the product dimensions.

For example, in the case of the flange width, the flange leg length in the T-shaped steel piece is substantially equal to the flange leg length in the product. That is, Fig. 1 is a view for explaining the dimension relationship of each part in the cross-sectional shape of the product. The flange leg length HEp is a half of the difference between the flange width Bp and the web thickness twp, It is necessary to set the flange leg length HE0 of the flange leg length HE0 of the product to be substantially equal to the flange leg length HEp of the product (in Patent Document 2, in most of the embodiments, the flange leg length of the T- In the embodiment of Patent Document 3, the difference between HE0 and HEp is a maximum of 1.5 mm. [0004] Patent Document 1 discloses a method of manufacturing a T- The relationship between the flange width and the flange leg length is not shown).

Thus, in the case of manufacturing the T-shaped steel by hot rolling, the flange leg length must be substantially the same between the T-shaped steel piece and the product, and therefore, in order to manufacture the T- It is necessary to prepare a large number of rolls of the rough milling machine for the flange leg length of the product.

For example, in the case of producing three kinds of products having flange widths of 100 mm, 125 mm and 150 mm, since the flange leg length is different by about 12.5 to 25 mm, in the conventional rolling method, It is necessary to prepare three sets in accordance with each of them, the roll cost becomes expensive, and it has been difficult to reduce the manufacturing cost.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems and provide a method and an apparatus for rolling a T-shaped steel product having a different flange width efficiently and at low cost.

When the flange leg lengths of the T-shaped steel piece and the product are substantially equal to each other, the thickness ratio of the T-shaped steel piece to the thickness ratio tf0 / tw0 of the product to the thickness ratio of the product It was determined to be the same or slightly larger.

That is, in the universal universal rolling, the reduction rate in the thickness direction of the flange and the web (hereinafter, referred to as the flange reduction rate and the web reduction rate, respectively) are set to be substantially equal or the flange reduction rate is set to be several percent larger. The reason is that, as described in Patent Document 1, the flange and the web are stretched in the longitudinal direction in the same direction to prevent bending of the pressurized steel sheet. In Patent Document 1, the reduction ratio of the flange to the web is almost the same Or the flange reduction rate is increased by about 3% depending on the dimensions.

The inventors of the present invention have found that, in order to grasp the influence of the dimension of each part of the T-shaped section and the rolling conditions in the rough rolling process to the finish rolling process on the dimensions of the respective sections of the T-section steel product, The change in flange leg length was examined in the rolling of T-shaped steel having a product height of 300 mm in web height and a flange width of 125 mm.

The flange reduction rate was set to be about 9% larger than the web reduction rate by setting the flange reduction rate to about 24% and the web reduction rate to about 15% at the beginning of the rolling with the web thickness of about 30 mm. A result that flange leg length greatly increased to about 6 mm before and after rolling was obtained.

Here, if the flange is pressed down more strongly than the web, there is a possibility that the rolled material is significantly bent toward the web side on the exit side of the rolling mill. However, in the initial stage of rolling in which the web thickness is large, a slight bending toward the web side occurs, It was small enough to be suppressed by a guide.

As described above, when the flange reduction rate is lowered by about 9% than the web reduction rate at the initial stage of the universal universal rolling with a large thickness of the flange and the web, the bending at the side of the rolling mill It is possible to increase the length of the flange legs in the range of the width of the flange to increase the flange leg length in the universal universal rolling and to divide the T-shaped steel having the flange width different from that of the T- ≪ / RTI >

The present invention has been achieved by further study based on the recognition, that is,

1. A rough rolling process for roughly shaping a billet in a roughly T-shape by a rough milling mill, and a T-shaped billet for roughly forming a T-shape by using a universal mill to press down webs and flanges, And a finish rolling step of rolling the T-shaped steel obtained in the intermediate rolling step to a product size, wherein a T-shaped steel having a flange leg length greater than the flange leg length of the T- Wherein a difference rf-rw between a flange reduction ratio rf and a web reduction ratio rw in a thickness direction of a web and a flange in a thickness direction of a web and a flange by a universal mill in the intermediate rolling step is set as a reduction ratio difference, At the first half pass of the rolling process, a pass for rolling in the range of 5 to 15% of the reduction rate difference is formed at least one pass With a method of producing a T-beams, it characterized in that the first plurality of paths are not pressed down by the front end flange edger rolling mill including a first pass or second pass 1 second.

2. The method according to claim 1, wherein the rolling of the flange and the web of the T-shaped steel piece in the rough rolling process is performed such that the ratio (tfo / two) of the flange thickness tfo and the web thickness two of the T- (Tfp / twp) of the flange thickness tfp of the section steel to the web thickness twp.

3. The web thickness of the T-shaped steel piece to be rolled in the rough rolling process is made smaller as the flange width of the product to be manufactured is larger than the product flange width in the case of not increasing the flange leg length in the intermediate rolling process Wherein the method comprises the steps of:

4. The flange width of the T-shaped steel piece to be rolled in the rough rolling process is made smaller as the flange width of the product to be manufactured is larger than the product flange width when the flange leg length is not increased in the intermediate rolling process Wherein the T-shaped steel is produced by the method according to any one of claims 1 to 3.

5. A rough rolling process for roughly shaping a billet in a substantially T-shape by a rough milling mill, and a T-shaped billet for roughly forming a T-shape by pressing a web and a flange with a universal mill, And a finish rolling step of rolling the T-shaped steel obtained in the intermediate rolling step to a product size, wherein the T-shaped steel having a flange leg length of the product longer than the flange leg length of the T- As a method for manufacturing a T-shaped steel to be manufactured, the rough milling mill in the rough rolling process uses one kind of roll grooved shape to change the web thickness of the T-shaped steel piece according to the product flange width As the edge mill of the above intermediate rolling process, roll coils having different coplanar depths according to the width of the product flange are divided and used By carrying out the rolling method of producing a T-beams, characterized in that for producing a T-beam of a plurality of different width size of the flange.

6. A rolling mill for a T-shaped steel having an intermediate pressure group consisting of a rough milling mill, a universal mill and an Ezer mill, wherein a cone depth HEe corresponding to a flange leg length of the T- And the flange leg length HEp of the T-shaped steel product is substantially equal to the flange leg length HEp of the T-shaped steel product.

7. A rolling mill for a T-shaped steel having a rolling mill group consisting of a rough rolling mill, a universal universal rolling mill, an Ezer rolling mill and a finishing universal rolling mill, the rolling depth HEe corresponding to the flange leg length of the T- And the flange leg length HEp of the T-shaped steel product is substantially equal to the flange leg length HEp of the T-shaped steel product of the roll of the rough shaping mill.

According to the present invention, it is possible to divide T-shaped steel having a plurality of different sizes of flange widths into one rough roll forming roll, so that the T-shaped steel of various flange widths And is industrially very useful.

1 is a view showing a cross-sectional shape of a T-shaped steel.
Fig. 2 is a view showing a cross-sectional shape of the T-shaped steel piece after rough-form rolling.
3 is a view showing the arrangement of the rolling line of the T-shaped steel.
Fig. 4 is a view showing the rolled state of the T-shaped steel piece and the geometric shape in the case of rough forming rolling.
5 is a view showing a rolling state of a first fundamental universal rolling mill of a T-shaped steel rolling facility.
6 is a view showing a rolled state of an edge mill of a T-shaped steel rolling facility.
7 is a view showing a rolling state of a second fundamental universal rolling mill of a T-shaped steel rolling facility.
8 is a view showing a rolling state of a finished universal rolling mill of a T-shaped steel rolling facility.
9 is a view showing the arrangement of the rolling line of the T-shaped steel.

(Mode for carrying out the invention)

A method of manufacturing a T-shaped steel and a rolling facility according to the present invention will be described using a T-shaped steel rolling facility shown in FIG.

The rolling mill of the T-shaped steel in the embodiment shown in Fig. 3 is characterized in that the rough shaping mill 1, the first rough universal mill 2, the eger mill 3 and the second rough universal mill 4 are brought close to each other And has a deployed intermediate pressure group. The concave depth HEe corresponding to the flange leg length of the T-shaped steel of the roll of the Ezer mill 3 is set to a value of a cone depth HE0 corresponding to the flange leg length of the T-shaped steel piece of the roll of the roughing mill 1, And is substantially equal to the flange leg length HEp of the T-shaped steel product.

A rectangular section steel billet such as a bloom to be a workpiece is rolled into a T-shaped section having a T-shaped section by the roughing mill 1 (rough rolling step). The obtained T-shaped section is subjected to rolling down of the web and the flange of the rolling mill in which the first rough universal mill 2, the edge mill 3 and the second rough universal mill 4 are arranged close to each other (intermediate rolling step) , And the finished universal rolling mill (5) finishes with T-shaped steel of the product size (finish rolling process). Fig. 1 shows the product sectional shape of the T-shaped steel, and Fig. 2 shows the sectional shape of the T-shaped steel piece.

The flange leg length HEp (FIG. 1) and the flange leg length HE0 (FIG. 2) in the T-shaped section of the product are substantially the same as those in the prior art. In the present invention, By increasing the flange leg length by controlling the reduction ratio and the web reduction ratio, the product having the flange leg length HEp of various dimensions is divided from the flange leg length HE0 of one T-shaped steel piece.

The length of the flange leg is controlled by forming at least one pass which increases the flange reduction ratio by about 10% with respect to the web reduction ratio in the first half of the universal rolling. By performing such rolling, a T-shaped steel piece having a flange leg length of 10 mm or more and a flange width of 20 mm or more can be rolled from the T-shaped steel piece having the same flange leg length, as compared with the case where the same is not performed.

However, the greater the difference in the reduction ratio between the flange and the web is, the larger the increase in the flange leg length is, but the more the bending toward the web is increased. Further, in order to obtain an increase in the effective length of the flange leg, the reduction rate of the flange and the web is set to 5% or more. Preferably, the reduction rate of the flange and the web is set to 6% or more, more preferably 6.2% or more.

That is, in the present invention, when the difference rf-rw between the flange reduction ratio rf and the web reduction ratio rw in the thickness direction of the web and the flange by the universal rolling mill in the intermediate rolling step is defined as the rolling reduction ratio, In the first pass, at least one pass (hereinafter referred to as a flange lowering pass) for rolling is performed in the range of the reduction rate difference of 5 to 15%. When the total number of rolling passes in the intermediate rolling process is an odd number of times, the time until the rolling down passes in the middle is defined as the first half pass.

It is preferable that the flange lowering pass which increases the flange leg length is carried out at an early stage of the rough universal rolling with less rolling bending. This is because, as the rough universal rolling progresses and the thickness of the flange or the web becomes smaller, the rolling bending of the flange to the web due to the lowering of the flange tends to occur.

Here, in order to enable rolling to increase the flange leg length, in the present invention, a cone-shaped depth HEe corresponding to the flange leg length of the T-shaped steel of the roll used for the eger mill 3 shown in Fig. 6, Shaped steel pipe 1 is approximately 10 mm or more larger than the hole depth HE0 corresponding to the flange leg length of the T-shaped steel piece of the roll of the rough shaping mill 1 shown in Fig. The fact that the cone depth HEe is substantially equal to the product flange leg length HEp means that the cone depth HEe is smaller than the product flange leg length HEp by 0 to 4 mm. By using the low and high rolls of such a cone-shaped depth HEe, it is possible to achieve the first-pass or the first-pass first pass including the first pass (normally, the first pass to the last flange- It is possible to increase the flange leg length in the under-flange lowering pass, and to increase the length of the flange under the flange under-pressure lowering path without decreasing the thickness of the web, It can be pressed down by an appropriate flange width corresponding to the flange width.

Further, in the present invention, in order to lower the flange more than the web, the ratio tf0 / tw0 of the flange thickness tf0 of the T-shaped steel piece to the web thickness tw0 in the preform rough rolling is set to be the flange Is larger than the thickness ratio (tfp / twp) of the thickness tfp and the web thickness twp. Here, the value of tf0 / tw0 is determined according to the ratio of the assumed product flange width (the product flange width when the flange leg length is not increased in the intermediate rolling process) and the flange width of the actual product to be rolled .

Here, as apparent from Fig. 4 showing the roughness of the rough roll forming, when the roll opening degree of the rough mill is changed, the web thickness tw0 mainly changes, and the flange thickness tf0 hardly changes. Therefore, in order to increase tf0 / tw0, it is necessary to roll the web thickness tw0 of the T-shaped steel piece to be thinner than usual.

For example, in the case of producing a product having a flange width of 150 mm with a rough-form rolling roll used for producing a T-shaped steel product having a flange width of 100 mm under ordinary rolling conditions, the flange width is increased by 1.5, Reduce the web thickness tw0 to a web thickness of 2/3. However, since it is possible to adjust some dimensions in the rough universal rolling process, it is not necessary to strictly reduce the web thickness tw0 to 2/3 of the web thickness, and allow about ± 10% of the thickness of the reciprocal of the flange width ratio It is good if the thickness is in the range.

As described above, in the case of increasing the flange width by the method of the present invention, the web thickness of the T-shaped steel piece in the rough forming rolling is set to be the same as that of the conventional method (the flange- Is not increased in the rolling process) and the product of the width of the product flange obtained by the method of the present invention. That is, as the manufactured flange width Bp is larger than the product flange width when the flange leg length is not increased in the intermediate rolling process, the web thickness tw0 of the T-shaped steel piece to be rolled in the rough rolling process is made smaller.

Here, by adjusting the web thickness, the larger the T flange width of the product flange width in the case where the product flange width Bp does not increase the flange leg length in the intermediate rolling process (the conventional method), the more the T It is necessary to reduce the flange width B0 of the steel pipe section. This is because the larger the flange width Bp of the product is, the larger the flange leg length HEp becomes. Therefore, the flange needs to be lowered than in the universal rolling, and the web thickness tw0 of the T- Since the same roughness is used in the rough forming rolling, the decrease width of B0 is the same as the reduction of tw0. However, even if B0 decreases, the flange width enlarging effect of the present invention can be obtained without any problem.

Further, in the intermediate rolling step, the rolling path for increasing the flange reduction ratio to a larger value than the web reduction ratio and increasing the flange leg length may be performed by any conventional universal rolling mill provided that a plurality of basic universal rolling mills are provided.

For example, in the case of the T-shaped steel rolling facility shown in Fig. 3, since the first fundamental universal rolling mill 2 and the second fundamental universal rolling mill 4 are provided as rolling mills in the intermediate rolling step, In the universal universal mill, the flange leg length can be increased.

In the intermediate rolling step of the rolling facility shown in Fig. 3, the first universal rolling mill 2 (U1) in the first pass of the universal rolling and the second universal rolling mill U2, U1, U1, U2, U3, U3, U3, U3, As shown in FIG. The number of passes from the first pass to the last pass is determined in the order of rolling regardless of which rolling machine is rolled.

In the intermediate rolling process, the Ezer mill (3) takes charge of controlling the flange width and the flange leg length by pressing down the flange end. As described above, the dimension HEe of the step between the large-diameter portion 33 and the small-diameter portion 32 of the edge mill 3 shown in Fig. 6 corresponds to the leg length of the T-shaped steel piece of the rough- (More than 0 mm to 4 mm) in consideration of a portion which is larger by 10 mm or more than the concave depth HE0 and which is equal to or smaller than the flange leg length HEp of the target product Quot; about 0 to 4 mm ").

Therefore, in the case of rolling a T-shaped steel having different flange widths, it is necessary to separately use the stepped HEe size suitable for the product in the roll forming process of the Ezer mill. However, the rough roll forming roll is not limited to the flange width of the product But may be a single roll shape having dimensions.

When a plurality of small-diameter portions 32 having different step differences HEe from the large-diameter portion 33 in the axial direction are formed on the rolls of the eger mill 3, it is possible to change the step difference HEe only by shifting the rolls in the axial direction Therefore, the burden on the roll cost is much smaller than in the case of replacing the rolls of the roughing mill.

Further, the rolling facility to which the manufacturing method according to the present invention is applied is not limited to the rolling facility shown in Fig. 3. For example, as in Patent Document 1, the rolling facility may be one in which the primary universal rolling mill is one, Can be applied to three or more periods.

Even when two universal rolling mills are arranged close to each other as in Patent Document 2, when the rolling mill for reducing the thicknesses of the web and the flange is substantially one of the roll mills, The manufacturing method according to the invention may be applied.

Further, as shown in Fig. 9, the manufacturing method according to the present invention can be applied even when the finishing universal rolling mill 5 is also used as the first fundamental universal rolling mill and the number of rolling mills is reduced. The rolling equipment of the T-shaped steel in the rolling line shown in Fig. 9 is characterized in that the rough shaping mill 1, the second rough universal mill 4, the Eger mill 3 and the finish universal mill 5 are arranged close to each other I have a rolling group. The concave depth HEe corresponding to the flange leg length of the T-shaped steel of the roll of the Ezer mill 3 is 10 mm or more larger than the concave depth HE0 corresponding to the flange leg length of the T-shaped steel piece of the roll of the rough shaping mill 1, And is substantially equal to the flange leg length HEp of the section steel product.

The T-shaped section formed by the rough forming mill 1 is subjected to reciprocating rolling of the second basic universal mill 4, the edge mill 3 and the finish universal mill 5 to the rolling mill row arranged close to the mill, (Intermediate rolling step), and in the final pass rolling, the final universal rolling mill 5 finishes the steel sheet into a T-shaped steel having the product dimensions (finish rolling step).

The rolling method of the present invention is applied to the second universal rolling mill 4 or the finish universal rolling mill 5 for rolling the intermediate rolling process so that the flange width is increased by reducing the flange.

Further, in the second universal mill 4, the web front end is not pressed down in the thickness direction, but since the web thickness is made uniform by the finish universal rolling mill 5, the web of the product can be made uniform in thickness.

In the second universal mill 4 and the edge mill 3, the flange is rolled outwardly in an inclined state, while the finish universal mill 5 is rolled in a state where the flange is vertical. However, if the inclination angle &thetas; of the flange is 10 DEG or less, stable rolling is possible, and no particular problem occurs.

Example

T-shaped steel was universally rolled using the T-section rolling facility shown in Fig.

[Conventional example]

A T-shaped steel having a product height of 300 mm, a flange width of 100 mm, a web thickness of 12 mm, a flange thickness of 19 mm and a product flange leg length HEp of 44 mm was produced by a normal rolling method.

A T-shaped steel piece having a web thickness tw0 = 48 mm, a flange thickness tf0 = 85 mm, a web height H0 = 370 mm, a flange width B0 = 136 mm and a flange leg length HE0 = 44 mm obtained by ordinary rough- , And the number of passes in the intermediate rolling process was set to 5 passes, and the first universal mill 2 and the second universal mill 4 performed universal rolling in five passes in total, namely, 10 passes in total.

Table 1 shows the pass schedule of the intermediate rolling process. The flange reduction rate of each pass is set to be 0 to 4% larger than the web reduction rate, but is less than 5 to 15% within the range of the present invention. The step height HEe of the Ezer mill was set to be 42 mm which is slightly smaller than the flange leg length HEp of the product.

After performing intermediate rolling according to the pass schedule shown in Table 1, one-pass finishing universal rolling was performed. The flange leg length after annealing was 43 mm, the flange leg length was 45 mm and the flange width was 100 mm Rolled products.

[Inventive Example 1]

As an example of the present invention, a T-shaped steel having a flange width of 150 mm is manufactured by using the same rough-mill roll as in the conventional example. Since the web height is 300 mm, the web thickness is 12 mm, the flange thickness is 19 mm, and the other cross-sectional dimensions are the same, the product flange leg length HEp is 69 mm. Thus, by using the method of the present invention, the flange leg length HEp is increased.

Corresponding to the fact that the product flange width is 1.5 times, the web thickness of the T-shaped steel piece rolled by the rough shaping rolling is changed to 32 mm which is 2/3 times that of the conventional example, and the dimensions of the T- tf0 = 85 mm, and flange width B0 = 120 mm. The flange leg length HE0 is 44 mm since the same roll was used.

Using this T-shaped section, basic universal rolling was performed based on the pass schedule shown in Table 2. The flange reduction rate of the U-2 to U-5 passes of the overall universal rolling was set to be 6 to 10% larger than the web reduction rate. In the U-6 to U-10 pass in the second half of the universal rolling, the flange reduction rate was 1 to 3% larger than the web reduction rate. The step difference of the Ezer mill was 67 mm in the point that the flange leg length HEp of the product was 69 mm.

In the pass schedule shown in Table 2, the flange leg length is smaller than the roll step of the Ezer mill in the Ezer rolling pass performed up to the first U-5 pass of the universal universal rolling. The flange leg length was increased by the rough universal rolling and the flange end was lowered from the Ezer rolling after the U-5 pass which was larger than the step of the lower roll, thereby reducing the flange leg length.

The dimensions of the rolled material subjected to the finish universal rolling after rough universal rolling with this pass schedule were measured. As a result, the product with the flange width Bp of 150 mm and the target dimension was rolled.

[Inventive Example 2]

As a second example of the present invention, a T-shaped steel having the flange width of 125 mm and other dimensions identical to those of the prior art and Inventive Example 1 was rolled by using the same rough roll mill same as the conventional example and Inventive Example 1. The product flange leg length HEp is 56.5 mm.

The web thickness of the T-shaped steel piece to be rolled by primary rough rolling was changed to 40 mm, and the dimensions of the T-shaped steel piece were set to a web thickness tw0 = 40 mm, a flange thickness tf0 = 85 mm and a flange width B0 = 128 mm. The flange leg length HE0 is 44 mm since the same roll was used.

Using this T-shaped section, rolling was performed in the intermediate rolling step in the same manner as in the case of the flange widths of 100 mm and 150 mm, based on the pass schedule shown in Table 3, and then subjected to finish universal rolling. Further, as the roll of the Ezer mill, a step HEe having a size of 54 mm was used. As a result of setting the flange reduction ratio of the U-2 and U-3 passes of the universal universal rolling larger than the web reduction ratio by about 6%, the T-shaped steel of the flange width as intended could be rolled.

From the above results, it was confirmed that, in the equipment for rolling the T-shaped steel having the flange width of 100 mm, the T-shaped steel having the flange widths of 125 mm and 150 mm can be rolled only by changing the size of the step HEe there was.

By using the manufacturing method according to the present invention, it is possible to produce a product of T-shaped steel having a different flange width, without replacing the rough roll forming roll.

According to the present invention, it is possible to divide T-shaped steel having a plurality of different sizes of flange widths into one rough roll forming roll, and T-shaped steel having various flange widths can be manufactured at a low manufacturing cost , Is very useful in industry.

1: primitive milling machine
2: First universal rolling mill
3: Ezer mill
4: Secondary universal rolling mill
5: Finishing universal rolling mill
10: T-shaped steel
11: web
12: Flange
21a, 21b: a horizontal roll of the universal universal rolling mill 2
22a and 22b: vertical rolls of the universal universal rolling mill 2
31a, 31b: a horizontal roll of the Ezer mill 3
32: Small neck
33: Large neck
41a and 41b: horizontal rolls of the universal universal rolling mill 4
42a and 42b: vertical rolls of the universal universal rolling mill 4
51a, 51b: a horizontal roll of the finish universal rolling mill 5
52a, 52b: a vertical roll of the finish universal rolling mill 5

Claims (7)

A rough rolling step of preliminarily shaping the billet in a roughly T-shape by a roughing and shaping mill, and a T-shaped steel piece roughly formed in a substantially T-shape by using a universal mill to press down webs and flanges, And a finish rolling step of rolling the T-shaped steel obtained in the intermediate rolling step to a product size, wherein a flange leg length of the product is smaller than a flange leg length of the T- As a method of producing a T-shaped steel for producing a long T-shaped steel,
The difference rf-rw between the flange reduction ratio rf and the web reduction ratio rw when the intermediate rolling process is performed in the thickness direction of the web and the flange by the universal rolling mill is made to be a reduction ratio difference, (1) or (2), wherein the rolling reduction is performed in a range of 5 to 15% in at least one pass, and at the first plural passes including the first pass or the first pass, And the steel sheet is not pressed down. The method according to claim 1,
The ratio of the flange thickness tf0 of the T-shaped steel piece to the web thickness tw0 (tf0 / tw0) of the T-shaped steel piece obtained after the rough rolling is determined so that the ratio of the T- (Tfp / twp) of the flange thickness tfp to the web thickness twp. 3. The method according to claim 1 or 2,
Wherein the web thickness of the T-shaped steel piece rolled in the rough rolling step is made smaller as the flange width of the product to be manufactured is larger than the product flange width when the flange leg length is not increased in the intermediate rolling process (METHOD FOR MANUFACTURING SHEET. 4. The method according to any one of claims 1 to 3,
Wherein the flange width of the T-shaped steel piece to be rolled in the rough rolling step is made smaller as the flange width of the product to be manufactured is larger than the product flange width when the flange leg length is not increased in the intermediate rolling step (METHOD FOR MANUFACTURING SHEET. A rough rolling step of preliminarily shaping the billet into a substantially T-shape by a rough milling mill, and a T-shaped steel ingot roughly T-shaped in a roughly T-shape, the web and the flange being pressed down by a universal mill, And a finish rolling step of rolling the T-shaped steel obtained in the intermediate rolling step to the product dimensions to produce a T-shaped steel whose flange leg length is longer than the flange leg length of the T-shaped steel piece As a method of producing a T-shaped steel,
As the rough milling mill of the rough rolling process, rolling is performed by changing the web thickness of the T-shaped steel piece in accordance with the width of the product flange by using one kind of roll shape. As the edge rolling mill of the intermediate rolling process, A method of manufacturing a T-shaped steel having a plurality of sizes of flange widths different from each other by producing a T-shaped steel by performing rolling by separately using roll coils having different coin depths according to a flange width. As a rolling facility for a T-shaped steel having an intermediate-pressure group, a universal rolling mill and an Ezer rolling mill,
The concave depth HEe corresponding to the flange leg length of the T-shaped steel of the roll of the Ezer mill is 10 mm or more larger than the concave depth HE0 corresponding to the flange leg length of the T-shaped steel piece of the roll of the rough shaping mill, And the flange leg length HEp. As a rolling facility for T-shaped steel having a rolling mill group consisting of a rough rolling mill, a universal universal rolling mill, an Ezer rolling mill and a finishing universal rolling mill,
The concave depth HEe corresponding to the flange leg length of the T-shaped steel of the roll of the Ezer mill is 10 mm or more larger than the concave depth HE0 corresponding to the flange leg length of the T-shaped steel piece of the roll of the rough shaping mill, And the flange leg length HEp.

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