JPH06307018A - Steel plate and steel strip ridged at opposite surfaces and manufacture thereof - Google Patents

Abstract

PURPOSE:To enhance the strength of a steel plate and to stabilize and uniform the coupling characteristic of the steel plate with respect to concrete or the like and to enhance the adhesive strength by setting ridges formed on opposite surfaces of a steel plate to be not in parallel with each other between both surfaces thereof. CONSTITUTION:A plurality of ridges 2 which are continuous widthwise of a steel plate are formed at each of opposite surfaces of the steel plate 10, being longitudinal spaces from one another, and the angles of the ridges 2 with respect to the widthwise direction of the steel plate 10 are set so that they are not parallel with each other between the opposite surfaces of the steel plate 10. Further, the height of the ridges 2 is set so as to maintain a steady-state in the longitudinal direction of the steel plate. Upon the manufacture of such a steel plate or a steel strip ridged at opposite surfaces thereof, steel is rolled by work rolls 1, 1 having gullivers 3 which are arranged so that the angles of the ridges 2 with respect to the widthwise direction of the steel plate 10 are set in such a way that the ridges are not in parallel with each other between the opposite surfaces thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate and a steel strip with double-sided ridges and a method for manufacturing them, in which the ridges are formed on both sides of the steel plate, and the double-sided ridges are used for reinforcing concrete members or as reinforcing bar joints. Steel plate and steel strip and its rolling, which can eliminate unevenness of ridge heights formed on both surfaces of the steel plate and uniformize the adhesive strength with concrete etc. is there.

[0002]

2. Description of the Related Art A steel sheet having a ridge formed on its surface is widely used as a civil engineering material or a building material for the purpose of joining with concrete or reinforcing it. As a method for manufacturing such a steel sheet with ridges, a method of forming ridges on the surface of the steel sheet by forming a caliber on a work roll in a strip rolling facility and rolling is common.

However, most of the steel plates with ridges currently manufactured are those having ridges formed on only one side of the steel plate. In particular, many vertically striped steel sheets having a continuous ridge in the longitudinal direction of the steel sheet are manufactured as members required to have adhesive strength with concrete. Specifically, the thickness of the thin part is 6
Vertical stripes having a ridge height of about 3 mm are formed with respect to ~ 22 mm, and are used for steel pipe piles and the like by using them for spirally formed steel pipes. At this time, in order to increase the adhesive strength, it is important to make the height of the ribs higher than that of a steel plate with ribs which is usually used as an anti-slip to make the distribution uniform. Many studies have been made in the past regarding this, for example, Japanese Patent Laid-Open No. 3-17.
Japanese Patent No. 4904 discloses a technique in which the crown of the rolling roll is set so that the change in the ratio crown in the final pass is small, and the heights of the ridges are made uniform.

Further, as a method of manufacturing a steel sheet having a ridge continuous in the width direction, for example, Japanese Patent Laid-Open No. 61-11931 is available.
Japanese Patent Publication No. 1 discloses that rolling is performed by limiting the angle formed by the caliber with respect to the cylinder length direction of the rolling roll in order to prevent warpage and camber during rolling.

[0005]

The conventional method for producing a steel sheet with a ridge as described above is intended to form a ridge only on one surface of the steel sheet, but it is formed into an electric resistance welded pipe, When it is used as a rebar joint or the like, strength on both sides of a steel plate is required for connection with concrete. In addition, when a structure integrated with concrete is to be obtained, even if one side has a favorable bonding relationship having both the tensile strength of steel and the excellent compressive strength of concrete, the other surface On the side, there is almost no demand for their connection, and it is often the case that the intended purpose cannot be achieved.

However, it is clear that the tensile force can be effectively dealt with by disposing the continuous ridges in the width direction on both sides of the steel plate, but the one in which the ridges are formed in the width direction of the steel plate as described above. In the case of rolling, the height of the ridges formed by bending the ridges on the front and back surfaces of the steel sheet is significantly reduced. That is, the present inventors have combined rolling rolls having various caliber shapes and examined the change in the protrusion weight portion on the front and back of the steel sheet.According to the results, the protrusions on the front and back of the steel sheet crossed and piled up simply as dots. In that case, a certain decrease in the height of the ridges is recognized, but if the ridges are entirely polymerized in the width direction, the height of the ridges on one side is 30%.
It is confirmed that the reduction is further reduced.

That is, as described above, in the portion where the ridge positions overlap on the front and back surfaces of the steel sheet, when it is attempted to obtain the same ridge height as compared to the portion where the ridges are present on only one side, the roll bite rolls. While the amount of metal that enters into the groove is required to be twice as much, the metal flow to the groove is suppressed by the tensile stress in the groove in the longitudinal direction, so that the protrusion is formed as compared with the case where only one side is formed. It can be said that the strip height does not become sufficiently high, but if the strip height at the strip weight on the front and back surfaces becomes low in this way, the adhesive strength of concrete at that part will be significantly reduced, and this is expected. It is impossible to obtain a good adhesion strength.

However, when a large number of ridges 12 continuous in the width direction of the steel plate 10 are continuously arranged in the length direction, a caliber of the same shape is symmetrical as shown in FIG. 1 or FIGS. 2 (a) and 2 (b). Rolls 11, 11, 11a, 11 formed on
When steel sheets are rolled by combining a, 11b and 11b vertically, even if the caliber position is different at the start of the process, as the rolling progresses, depending on the longitudinal position of the steel sheet, the ridges on the front and back Areas where parts do not overlap at all and areas where they overlap completely appear, and in the area where ridges overlap, sufficient ridge height cannot be formed, resulting in a situation where the adhesion strength with concrete as a product varies greatly depending on the steel plate sampling position. To do.

That is, even if the caliber positions of the upper and lower rolls are adjusted at the start of rolling, a slight difference in frictional resistance between the upper and lower rolls at the time of unsteady rolling, a peripheral speed difference, a diameter difference, etc. subtly influences the protrusion. A region where the line positions completely overlap with each other on the front and back sides is generated, and the height of the obtained line changes significantly.
For example, the upper and lower work roll diameters are 800 mm and 79, respectively.
When there is a diameter difference of 1 mm such as 9 mm, the rolling position shifts 50 mm in the longitudinal direction when rolling 40 m. However, since the ridges required for ordinary steel plates are formed at a pitch of about 30 to 50 mm in terms of the adhesion strength with concrete, the ridge positions on the front and back surfaces are initially perfect as shown in Fig. 3 (a). Even if it is shifted to
As shown in FIG. 3B, a completely overlapping portion is generated, and the height of the protrusion 12 is greatly reduced in the case of FIG.

The region having a low height of the ridges 12 generated as described above cannot be obtained because the desired characteristics cannot be obtained in the end, which requires an extra step and lowers the yield. This leads to inconvenience such as being unable to guarantee the product length.

[0011]

Means for Solving the Problems The present invention has been studied to solve the problems in the prior art as described above, and was formed on a work roll when rolling a steel sheet having ridges formed on the front and back sides. A preferable solution is achieved by setting the caliber to a specific state, and is as follows.

(1) A plurality of ridges continuous in the plate width direction are formed on both sides of the plate in the longitudinal direction of the plate so that the angles of the ridges with respect to the plate width direction of the steel plate are not parallel on the front and back surfaces of the steel plate. A steel plate with double-sided ribs that is characterized by

(2) Plural ridges continuous in the plate width direction are formed on both sides of the plate in the longitudinal direction of the plate so that the angles of the ridges with respect to the plate width direction of the steel plate are not parallel on the front and back surfaces of the steel plate. A steel strip with double-sided ridges, characterized in that the peak height of the ridges maintains a steady state in the lengthwise direction of the steel strip.

(3) When rolling a steel sheet having a plurality of continuous ridges extending in the plate width direction in the longitudinal direction of the plate, the angle of the ridge with respect to the plate width direction of the steel sheet is the surface of the steel sheet. A method for producing a steel plate with double-sided ridges and a steel strip, which comprises rolling between work rolls having calibers formed so as not to be parallel on the back surface.

[0015]

[Function] The ridges continuous in the plate width direction are formed on both sides of the plate in the longitudinal direction of the plate so that the angles of the ridges with respect to the plate width direction of the steel plate are not parallel on the front and back surfaces of the steel plate. As a result, it is possible to obtain a balanced resistance effect on the front and back of the steel sheet by bonding and adhering with concrete, and a reinforcing effect due to the ridge is also obtained on the front and back of the steel sheet in a mesh-like uniform distribution condition.

Since the peak height of the ridges maintains a steady state in the lengthwise direction of the steel strip, it is possible to stably obtain the adhesive strength with concrete or the like in which the total length of the steel strip is constant, and the initial characteristics High yield of steel plate with high yield.

When rolling a steel sheet having a plurality of ridges continuous in the plate width direction on both sides in the longitudinal direction of the plate, the angles of the ridges with respect to the plate width direction of the steel plate are parallel on the front and back surfaces of the steel plate. By rolling between work rolls that have calibers formed so that they do not occur, even if there is a deviation due to diameter difference, peripheral speed difference, friction resistance difference, etc. during rolling, the protrusions on the front and back of the steel plate Completely prevent the generation of areas that are completely polymerized.

Even if the ridges on the front and back sides of the steel sheet overlap at the crossing position, they are partial, and the metal flow to the caliber groove portion is instantaneously returned to the original state, so that the ridge height is less affected. Furthermore, since the changes in the height of the ridges are averaged in the lengthwise direction of the steel sheet, the influence on the concrete adhesion strength is practically negligible.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention as described above will be described with reference to the accompanying drawings.
As shown in some examples in FIG. As proposed, the ridges 2, 2 are generally linear as shown, but may be appropriately curved depending on the case.

In order to manufacture the steel sheet of the present invention as described above, the steel sheet 10 is provided with the work roll 1 as shown in FIG.
1. When rolling and forming a plurality of ridges 2 continuous in the plate width direction on the front and back sides in the longitudinal direction of the steel plate 10, the angles of the ridges 2 are parallel on the front and back faces of the steel plate 10. Caliber 3, 3 ─, which was formed so as not to become
Rolls 1 and 1 having 3, 3 are prepared and rolled between the rolls 1 and 1.

The form of the steel plate obtained by the one shown in FIG. 4 is as shown in FIG. 5, and the ridges 2 and 2 on the front and back of the steel plate 10 have the relationship as shown. That is,
The ridges 2 and 2 on the front and back sides intersect at an intersection 4 as shown in the drawing, but the intersection 4 is only a point in view of the overall length of the ridges 2 and 2, and moreover, in the width direction of the steel plate 10. Since the position of each of them and the lengthwise direction are sequentially different, the bonding strength with concrete or the like hardly changes as a whole.

Another typical arrangement relationship of the ridges 2 according to the present invention is as shown in FIG. 6 described above, and the one in FIG. 6B shows the case where the inclination angle of the ridge is increased, and FIG. 7B shows the case where the inclination angles of the ridges 2 and 2 on the front and back of the steel plate 10 are different. Further, FIG. 5C shows the case where the ridges 2 and 2 are bent at the widthwise intermediate portion of the steel sheet 10, but in any case, the intersection 4 of the ridges 2 and 2 becomes a dot shape.
A relationship similar to that of is constructed.

The caliber state in the rolling or work roll of the above-mentioned FIG. 6 is separately shown in FIG.
It is obvious that the steel plate 10 obtained by rolling by forming the caliber 3 in the rolls 1a, 1b, 1c as shown in FIGS.

It should be noted that the above-mentioned ones shown in FIGS.
Even if some protrusions 2 are bent like (C),
The ridges 2 to calibers 3 are in principle linear. However, it is obvious that the ridges 2 on the steel plate 10 or the calibers 3 on the roll 1 according to the present invention may be curved such as corrugated.

[0025]

[Manufacturing Example] Hot rolling a slab to obtain a steel plate with ridges for reinforcing the connection with concrete. Incorporating ordinary flat rolls into the 1st to 4th stands by the hot finish rolling mill, and the 5th stand. As a final rolling stand, caliber rolls as shown in FIG. Slab dimensions are 250mm ^t x 1230mm ^W x 7000
mm ^L , and the heating temperature was 1250 ° C. After rolling to a bar thickness of 35 mm with a rough rolling mill, finish rolling was performed under the conditions shown in Table 1 below.

[0026]

[Table 1]

The specifications of the steel strip with double-sided ridges produced by rolling have a ridge height of 2.5 mm or more and a ridge width of 8 mm.
mm, the longitudinal pitch of the ridges is 38 mm. As the work roll of the caliber roll, one having an upper roll diameter of 750φ and a lower roll of 749φ was used by surface grinding.

When the caliber roll as described above is used and the angle between the front and back surfaces of the caliber with respect to the plate width direction is the same as shown in FIG. Every time the rolling is performed for 2.36 m, the upper and lower ridges are displaced from each other by 3.1 mm in the longitudinal direction, so that the displacement of 38 mm (one pitch) is generated in about 12 laps. On the other hand, the total length of the steel strip according to the above manufacturing example is about 400
m, and the height of the ridges in this case was uniform.

That is, FIG. 8 shows a summary of the rolling results according to the prior art as described above for the coil longitudinal direction distance of 100 m, and the average peak height of the average ridge per side is about 28 m for the coil length. Although it is obtained as a 2.8 mm steady portion, an unsteady portion is generated between such steady portions over a coil length of about 6 m, and in this unsteady portion, the average peak height is 1.9 to 2.2 mm / one side. And the average mountain height of the stationary part is 6
It was about 8 to 79%.

On the other hand, in the above-described manufacturing example of the present invention, as shown in FIG. 9, the average peak height of the ridges is 2.75 to 2.85 mm over the entire length of the steel strip over about 400 m,
The occurrence of unsteady parts as in the prior art was not recognized.

That is, the conventional method as described above has insufficient bondability with concrete in the range of the unsteady part as described above, and in order to obtain a stable bond strength, the part must be removed. is necessary. The above-described product according to the present invention is a product capable of obtaining a stable and uniform bond strength with concrete in which a steel strip having a length of several hundred meters or more is generally stable.

[0032]

As described above, according to the present invention, the ridges formed on the front and back surfaces of the steel sheet are not parallel to each other to stabilize the strength of the steel sheet and also to improve the bonding property to concrete. In order to stabilize and homogenize the ridge height and roll it appropriately in a uniform state, it is possible to provide a steel sheet having high adhesion strength with concrete as described above with high yield and efficiently. It is a device that has a large effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a rolling situation according to a conventional technique.

FIG. 2 is a cut front view showing another rolling situation according to the prior art.

FIG. 3 is an explanatory diagram showing a relationship between ridges formed on the front and back sides of a steel plate in the conventional technique as shown in FIGS. 1 and 2.

FIG. 4 is a perspective view of a rolled steel sheet according to the method of the present invention.

5 is an explanatory diagram showing a plan view of a state of steel obtained by the method of FIG. 4. FIG.

FIG. 6 is a plan view of a steel sheet obtained in another embodiment according to the present invention.

7 is a cut front view showing a rolled state for obtaining the steel sheet shown in FIG.

FIG. 8 is a chart summarizing a change state of the average protrusion height per one side in the coil longitudinal direction according to the related art.

FIG. 9 is a chart summarizing a distribution state of average protrusion heights per side in the coil longitudinal direction according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work roll 2 Ridge in a steel plate 3 Caliber 4 in a roll 4 Intersection between ridges 2 on the front and back of the steel plate 10 Steel plate 11 Work roll 11a in the related art 11a Work roll 11b in the related art Work roll 11 in the related art 12 Ridge in the related art 13 Conventional technology Roll Caliber in

Claims (3)

[Claims] 1. A plurality of ridges continuous in the plate width direction are formed on both sides of the plate in the longitudinal direction of the plate so that the angles of the ridges with respect to the plate width direction of the steel plate are not parallel on the front and back surfaces of the steel plate. A steel plate with double-sided ribs that has been characterized. 2. A ridge continuous in the plate width direction is formed on both sides of the plate in the longitudinal direction of the plate so that the angle of the ridge with respect to the plate width direction of the steel plate is not parallel to the front and back surfaces of the steel plate. In addition, a steel strip with double-sided ridges, characterized in that the peak height of the ridges maintains a steady state in the longitudinal direction of the steel strip. 3. When rolling a steel plate having a plurality of continuous ridges extending in the plate width direction on both sides of the plate in the longitudinal direction, the angle of the ridges with respect to the plate width direction is the front and back surfaces of the steel plate. And a method for manufacturing a steel strip with double-sided ridges, which comprises rolling between work rolls each having a caliber formed so as not to be parallel to each other.