JPH0669561B2 - Rolling method for steel plate with protrusions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Object of the Invention” The present invention relates to a method for rolling a steel plate with projections, and provides a rolling method capable of accurately obtaining an arbitrary projection height over a wide range of plate thicknesses by the same caliber roll. It is what

Industrial application field Rolling technology for steel plates with protrusions that are formed for the purpose of improving the bondability with concrete, etc. or reinforcing or preventing slippage.

Conventional technology It has been practiced to hot-roll a steel plate with a caliber roll, but the method is to fill the caliber with rolling material to form a projection with the desired height. It is what That is, it can be said that it is based on the technical concept that the height of the caliber is inevitably the same when the material is filled in the caliber.

Problems to be Solved by the Invention However, when the conventional method as described above is used, it is necessary to prepare a dedicated caliber roll for each in order to immediately respond to various changes in the intended height of the projection. It is necessary and cannot respond to these changes without preparing a large number of caliber rolls.

Further, as described above, in order to fill the steel material into the caliber, the rolling force against the caliber roll must be considerably high, and the rolling energy becomes large. Furthermore, in order to obtain a proper projection, the desired rolling condition cannot be obtained unless many trial rollings are performed.

EXAMPLE To further explain the present invention as described above, in FIG. 1, a caliber roll 1 is arranged with respect to a flat roll 2 and a steel plate 3 having a plurality of projections on one surface of the steel plate is continuously rolled in the rolling direction. In the hot rolling tandem mill, this caliber roll is incorporated into the final rolling stand, but if the inlet plate thickness is to and the rolled plate thickness is t, this pass The amount of reduction Δt of
Since Δt = to−t, the inventors of the present invention conducted many experiments on the influence of the shape of the caliber 4, the plate thickness to and the reduction amount Δt on the height of the post-rolling protrusion in such a case, and made repeated studies. As a result, the relationships shown in FIGS. 2 and 3 were confirmed.

That is, print rate [projection height h / reduction amount Δt × 100 (%)]
Is influenced by the caliber angle θ, the caliber width wb, and the caliber pitch (value obtained by subtracting the caliber width wb from the caliber center position interval SR) SR ′, and the larger θ and wb / SR ′, the larger the printing rate η can be obtained. As an example, the relationship between the print rate η and the rolling reduction Δt is shown in the model experiment of caliber width wb = 30 mm, caliber pitch (SR ′) = 9.5 mm, roll diameter 220 mm, caliber angle θ = 60 °. FIG. 2 shows the appearance when the entrance side plate thickness is variously changed in the case. That is, for example, the entrance side plate thickness is 4 mm
With a reduction of 1 mm, the print rate is 80%, and the height of the protrusion is 0.8 mm. Even with this reduction of 2 mm, the print rate is 86.5% and the height of the protrusion is 1.73 mm. On the other hand, when the entry side plate thickness is 8 mm, the printing rate is 55% and the projection height is only 1.1 mm when the reduction amount is 2 mm. That is, the print rate increases as the reduction amount increases, but the print rate becomes saturated when the reduction amount increases to some extent.

Also, at the same amount of reduction, it is affected by the entry side plate thickness to: the thicker the entry side plate thickness to, the lower the protrusion height, and the thicker the plate thickness, the greater the amount of reduction required to obtain the same protrusion height. To obtain this same protrusion height, the caliber shape, that is, the caliber width wb also influences. Fig. 3 shows the influence of the entry side plate thickness and the caliber width wb on the reduction amount Δt required to obtain a protrusion height of 3.0 mm in the actual machine with the conditions of the model experiment tripled. In this case, the roll diameter is 550 mmφ, the caliber width distance SR ′ is 28.5 mm, and the caliber angle θ = 60 ° is constant, and even if the caliber width to is the same, the required reduction is required. The amount will increase.

Fig. 4 shows the relationship between wb / SR ', caliber angle θ, and print rate η. The conditions of the caliber roll are the same as those in Fig. 3 and the roll diameter is 660 mm.
φ, caliber pitch 28.5mm, caliber width wb
These are 36.5 mm, 7.8 mm and 9.0 mm, but when the caliber width wb is constant, the print rate η increases when the caliber pitch SR ′ is reduced. The relationship between the print ratio and the required reduction amount is as shown in FIG. 4, and this required reduction amount is for obtaining a protrusion height of 3.0 mm.

By the way, as described above, the following formula I exists between the projection height h, the reduction amount Δt, and the print rate η.

.DELTA.t = h.multidot.100 / .eta .... I In the above equation, however, it was confirmed that the print rate .eta. Is as in the following equation II as a result of many practical studies conducted by the present inventors.

η = f (wb, SR ', θ, to, D) …… II That is, it depends on the print ratio obtained by the caliber width, caliber pitch, caliber angle, entrance side plate thickness and roll diameter, and the projection height to be obtained. If you decide the amount of reduction and roll,
Since the predetermined protrusion height can be obtained, the target protrusion height can be obtained regardless of the caliber depth. Therefore, the caliber depth is prepared as a value appropriately larger than the maximum value of the projection height obtained by the roll, and the caliber roll is used with the inlet side plate thickness used in consideration of the relationship of the above formulas I and II. The print rate can be obtained from the relationship, and the required amount of reduction Δt can be obtained from the relationship between the print rate and the projection height to be obtained, and the target projection height can be realized substantially accurately. . For example, as shown in Figs. 3 and 4, if the target projection height is 3.0 mm, the caliber width becomes
9.0mm, caliber angle θ is 60 °, caliber pitch SR 'is 28.
When the roll diameter is 5 mm and the roll diameter is 660 mm, Δt = 0.158 ・ to +
It can be expressed as 1.80.

It should be noted that the height of the protrusions arranged in the plate width direction as described above tends to be low at the edge portion of the plate width, but in order to prevent such a phenomenon, the caliber width is increased from the roll center toward the edge part. By making it larger, the height of the protrusions in the plate width direction can be made uniform, and by doing so, even protrusions having a height of 3.0 mm or more can be obtained in an appropriate and uniform state. Further, by using the steel plate thus obtained, it becomes possible to appropriately manufacture a spiral steel pipe with inner surface projections and the like.

A concrete production example of the device according to the present invention is as follows.

When manufacturing products with required projection height of 4 mm or less on steel plate, the caliber depth is 5.1 mm and the roll diameter is 660 mm.
φ, caliber interval SR is 28.5 mm, caliber angle θ is 60 °, inlet side plate thickness is 14 mm, and the amount of reduction is constant at 5.0 mm, and the caliber width wb is changed to 7.8 mm, 8.4 mm, 9.0 mm. The heights were obtained as 3.25 mm, 3.50 mm, and 3.90 mm, respectively.The actual results are 3.2 when the caliber width wb is 7.8 mm.
1 to 3.29 mm, 3.46 to 3.55 mm when the caliber width is 8.4 mm,
When the caliber width was 9.0 mm, it was possible to obtain a protrusion height of 3.86 to 3.94 mm.

When rolling a steel plate with a required projection height of 3.0 mm and a projection thickness of 6 to 22 mm, the caliber roll conditions are as follows: caliber depth h is 5.1 mm, caliber width wb = 7.8 mm, caliber interval SR =
With 28.5 mm and caliber angle θ = 60 °, the necessary reduction amount at each plate thickness is Δt = h · 100 / η, η = f (wb, SR, θ, to,
The result obtained by D) is as shown by o in FIG. 5, and the projection height obtained by concrete rolling according to such required reduction amount is as shown by. As a result, highly accurate rolling such as ± 0.05 mm or less was obtained in a wide range of plate thickness.

The specific rolling conditions and projection heights in this case are as shown in the table below, and the hot rolling stand finishing rolling mill was carried out by using the above-mentioned caliber roll for the first stand or the third stand. .

"Effect of the invention" According to the present invention as described above, it is possible to accurately roll a steel plate having an arbitrary protrusion height in a wide range of plate thicknesses by the same caliber roll,
It is an invention that is industrially highly effective.

[Brief description of drawings]

The drawings show the technical contents of the present invention. FIG. 1 is a cross-sectional explanatory view of a caliber shape for rolling a steel plate with protrusions, and FIG. 2 is an influence of a reduction amount and an inlet side plate thickness on a print rate. Fig. 3 shows an example of the above, Fig. 3 is a diagram showing the influence of the entry side plate thickness and caliber width on the amount of reduction required to obtain a protrusion height of 3.0 mm, and Fig. 4 is the print rate and protrusion height. A chart showing the relationship between the amount of reduction required to obtain 3 mm and the caliber shape (caliber width / interval between calibers). Fig. 5 shows the required amount of reduction and projection plate thickness (input 2 is a table summarizing the relationship between the thickness of the side plate) and the measured height of the protrusion obtained by rolling. However, in the above drawings, 1 is a caliber roll, 2 is a flat roll, 3 is a steel plate, and 4 is a caliber.

Claims (1)

[Claims] 1. When rolling a steel plate with protrusions having a thickness of 6 mm or more by means of a caliber roll by means of a hot rolling stand, the caliber depth of the roll is made larger than the maximum value of the protrusion height obtained by rolling. A method for rolling a steel sheet with projections, comprising rolling with a required amount of reduction Δt according to the following formula using a caliber roll. Δt = h · 100 / η ………… I η = f (wb, SR ′, θ, to, D) …… II However, in these equations, h is the protrusion height, η is the print ratio, and wb is Caliber width, SR 'is the caliber pitch, θ is the caliber angle, to is the entrance side plate thickness, and D is the roll diameter.