JPH0356801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rolling technique for producing a wide strip with narrow and high vertical stripes, and more particularly, it relates to a rolling technique for manufacturing a wide strip with narrow and high vertical stripes, and more particularly, to a rolling technology that is more suitable than conventional wide strips with vertical stripes. The present invention relates to a rolling method for producing strips with high vertical stripes.

[Conventional technology]

Generally, a strip is rolled several times by two cylindrical rolling rolls to form it into a predetermined size having a substantially uniform thickness.

Furthermore, using such strip rolling equipment, strips can be rolled by forming grooves or protrusions of various shapes on the rolling rolls of the final rolling pass, as shown in Japanese Patent Publication No. 52-34022, for example. It is possible to produce strips with projections or grooves of various shapes on the surface of the plate. Such strips have special functions and are used for a variety of purposes.

Among such strip plates with protrusions or grooves, as shown in FIG. 2, an example of the cross-sectional shape thereof, there are thick protruding parts 7 at regular intervals in the width direction. A strip plate is produced in which the flesh portion 7 is substantially continuous in the length direction of the strip to form vertical stripes, and is called a vertical striped steel plate.

To give a specific example, the vertical striped steel plates currently manufactured have vertical stripes formed at regular intervals of 10 mm to 20 mm in the width direction, and the width of the strip is 600 to 1230 mm.
The thickness t of the thin part of the strip is 1.6 to 4.5 mm,
The width of the vertical stripe w is 4 to 6 mm, the height of the vertical stripe Δt
is 2mm to 4mm. These vertically striped steel plates have a high rigidity relative to their weight, so they are used not only as strength materials for car side panels and steel pipes, but also for floorboards and truck beds to prevent slipping. Furthermore, because of its excellent heat dissipation effect, it is used in an extremely wide range of applications, such as in motor frames.

As another example, Japanese Patent Laid-Open No. 60-37484 discloses the use of a vertically striped steel plate having a similar shape to the above-mentioned vertically striped steel plate for a spirally formed steel pipe. This steel pipe is used as a composite pile by filling the inside with concrete, and the purpose is to improve the adhesion strength with concrete by the protrusions on the inner surface of the steel pipe. In this case, the distance between the vertical stripes in the vertically striped steel plate is in the range of 15 to 100 mm.

Such strips having vertical stripes have widths and thicknesses within the same range as ordinary strips, and are therefore manufactured using ordinary strip manufacturing equipment. In other words, the finishing rolling pass of the strip consists of a plurality of rolling passes in which the strip is passed between two upper and lower rolling rolls and rolled to a predetermined thickness. In order to form the shape, in the final rolling pass to shape the cross section into a predetermined shape, vertical stripes are formed along the circumferential direction on the body of at least one of the two roll rolls 1 and 2, the upper and lower rolls. If grooves 3 are provided, vertical stripes can be formed at positions corresponding to the grooves.

[Problem that the invention seeks to solve]

By the way, conventionally, for reasons explained later, rolling passes in which vertical grooves were formed on the rolling rolls were provided only in the final pass, and the cross section of the strip immediately before the final pass was made to have a substantially uniform thickness. was. In such a case, the position in the width direction where the vertical stripes exist and the desired width w of the vertical stripes can be obtained, but a sufficiently high height Δt of the vertical stripes cannot be obtained.
This is because even if the strip is rolled with sufficiently deep grooves in the rolling rolls of the final rolling pass, as shown in FIG. The vertical striped grooves 3 are not filled sufficiently and voids 4 are formed, and there is a limit to the height Δt of the vertical stripes that can be obtained by forming only the final rolling pass.

The reason stripes with vertical stripes are used is because of the special effects they provide, such as high rigidity, anti-slip effect, heat dissipation efficiency, or adhesion to concrete. Naturally, the higher the height Δt of the vertical stripes, the more desirable it is. For example, in the vertically striped steel plate that is used as the material for the concrete-filled composite pile mentioned above, the height of the vertical stripes is at most 4 when formed only in the final rolling pass.
Only 2 mm thick stripes can be obtained, and in some cases it may be difficult to form vertical stripes with a height of 2 mm.
However, from the viewpoint of usability, it is required to form vertical stripes of 5 mm or more.

In order to satisfy such requirements, it is conceivable to first increase the amount of plate thickness reduction in the final rolling pass. However, this means an increase in the rolling load of the final rolling pass, and there is a limit on the equipment. Next, if the width w of the vertical stripes is increased, the material can easily enter the grooves of the rolling rolls, and the height Δt of the vertical stripes can be slightly increased. However, when the width of the vertical stripes increases, the weight of the strip increases compared to the improvement in usage performance, which leads to an increase in price, and in cases where the purpose is heat dissipation, the usage performance deteriorates.

The present invention was developed to solve the above-mentioned problems, and provides a method of rolling a wide strip having vertical stripes with better performance without increasing the load applied to the rolling mill.

[Means for solving problems and their effects]

The technical means of the present invention for solving the above problems is to roll a wide strip plate having a predetermined plate width and a ratio of the plate width to the average plate thickness of 25 or more in a plurality of rolling passes, At a predetermined position in the width direction of the wide strip plate during the final rolling pass, in which a predetermined longitudinal groove is carved in at least one of the rolls, which is composed of two upper and lower rolls. The width is 15mm or less and the height is 2
In a rolling method in which protruding vertical stripes of mm or more in size are substantially continuously formed in at least one location, the longitudinal stripes are formed at the position where the protruding longitudinal stripes are formed in the rolling process before the final rolling pass of the strip. The strip plate is formed to be thicker than the average plate thickness over a width at least 10 mm wider than 1/3 of the width of the strip plate, and then the final rolling pass is performed.

In this case, the preforming method does not need to be particularly limited, but in the finish rolling process of the strip, usually multiple rolling stands are used and each rolling stand performs one pass of rolling. It is most rational to use a rolling stand that shares the rolling passes, and to roll the body of the roll by grinding it into a shape corresponding to the desired preform cross-sectional shape.

In order to understand the superiority of the method of the present invention, a comparison with conventional methods will be explained below.

Generally, in order to roll and form the cross section of a rolled material into a predetermined shape, a multi-pass forming method is used in which the shape of the rolling roll is changed stepwise in multiple rolling passes. This is a very commonly used method. Therefore, in order to form vertical stripes on the surface of a strip that are higher than conventional stripes, it seems easy to form vertical stripes with multiple rolling passes, but In the case of plates, conventionally all strips with vertical stripes were rolled with vertical stripes only in the final rolling pass, because the so-called meandering of the strip, in which the strip is rolled with deviation in the width direction, is unavoidable. was.

In order to clarify the reason for this, the problem when applying the multi-pass forming method to the rolling of a strip having vertical stripes as shown in FIG. 5 will be explained by analogy with the above-mentioned profile rolling.

In this case, as shown in FIG. If it is rolled so as to match the vertical striped grooves 3, sufficiently tall vertical stripes 7 can be formed as shown in FIG. 2B. However, in actual strip rolling operations, the meandering phenomenon in which the strip S is rolled with a slight deviation in the width direction of the strip is unavoidable, and generally
As shown in FIG. 2, the preformed thick protruding portion 5 and the vertical striped grooves 3 of the final rolling roll are rolled with a deviation of δ in the width direction. In this case, since there is no effect of preforming, the portions of the strip S that are rolled with the vertical striped grooves 3 have vertical stripes 7 of the same height as in the case of forming only by the final rolling pass, as shown in Fig. d. ' can only be obtained.
In actual operation, the meandering amount δ of the strip is not constant, so the height of the vertical stripes is high where δ is almost zero, and the height of the vertical stripes is low where δ becomes large. An unsatisfactory strip is obtained in which the height of the stripes varies along the length of the strip. Because of these problems, as mentioned above, strips having vertical stripes have conventionally been manufactured using only the final rolling pass to form the vertical stripes.

In order to solve these problems, the inventors of the present application have researched a preform shape that can form sufficiently high vertical stripes even if the strip meanders to some extent. As a result, if a strip is preformed to have a thick section in a wider range than the meandering amount of the strip, centered on the position in the width direction where a predetermined vertical stripe is to be formed, it is possible to Recalling that the influence of meandering of the strip can be reduced, we also clarified the limit value of the width of the thick part in the preformed cross section, and developed a strip with a cross-sectional shape in which the thick part is formed in such a wide range. The present invention was made by experimentally confirming that even when using the same method, sufficiently high vertical stripes can be formed in the final rolling pass.

That is, as shown in FIG. 6a, the principle of the present invention is that even if the strip S is rolled with a deviation of δ, the width of the thick portion 5 in the preformed cross section will be smaller than the predetermined width w of the vertical stripes by 2δ. If the range is wide, the vertical striped grooves 3 of the final rolling roll 1 will be within the width of this thick part 5, and if this strip S is rolled, it will have sufficiently tall protruding vertical grooves as shown in Figure b. A stripe 7 can be formed. In this case, compared to the case shown in FIGS. 5a and 5b, where the material has already entered the vertical grooves 3 to some extent in the preformed cross section, the vertical grooves 3
At first glance, it seems that the preformed cross-sectional shape of the present invention is not very effective because the vertical stripes 7 of the same height cannot be obtained unless the amount of material to be introduced into the material is large. However, if you think about it carefully, the amount of reduction in the thickness of the thick portion is greater than that in the case of rolling from a cross section of uniform thickness. Therefore, as long as the thick part is local,
This makes it possible to increase the amount of material that enters the longitudinal grooves without increasing the load on the rolling mill.

By the way, even if the strip is shifted by ±δ, in order for the thick part 5 of the preformed cross section to completely cover the vertical striped grooves 3 of the roll as shown in FIG. It is necessary that the width W of the part is at least 2δ wider than the vertical stripe width w of the finished product. However, as will be shown later in Examples, experiments have shown that the thick portion 5 of the preformed cross section is formed by the vertical striped grooves 3 of the roll.
It was found that it is not necessary to completely cover the width w of , and that covering approximately 2/3 of it has the same effect as completely covering it.

This condition is based on the positional relationship shown in Figure 1a: 1/2Wδ+(2/3-1/2)w=δ+1
/6w ∴W1/3w+2δ ...(1) It is expressed as follows.

That is, the width W of the thick portion 5 in the preformed cross section
does not need to be 2δ wider than the width w of the vertical stripes of the finished product; it is sufficient that it is 2δ wider than 1/3 of w.

Note that when rolling a profile, the width B of the profile is within a range that is not very large compared to the typical thickness h, so the meandering of the material may be prevented by the hole shape of the roll itself or by the vertical rolls or guides. Easy to restrain. Therefore, when forming the cross-sectional shape gradually by multi-pass forming, there is no need to take into account the effect of meandering of the profile. Also, in the field of rolling wide strips, for example,
A technology in which a multi-pass molding method is applied to 9911 has been disclosed. However, in this case, the cross-sectional shape of the product is such that the plate thickness gradually varies over a wide range in the width direction, and even if the strip plate meanderes to some extent, it will not have any effect. Therefore, in this case, it is sufficient to keep the meandering of the strip within the normal range.
There is no technical idea to reduce the influence of meandering of the plate when determining the preform cross-sectional shape.

Next, the reasons for each limitation in the present invention will be explained.

The reason why the ratio B/h of the width B of the strip to the average thickness h is set to 25 times or more is because if the width is narrower than this, the meandering of the strip can be easily restrained with a roller guide, etc. This is because there is no need to use a method.

The reason why the width w of the vertical stripes on the product is set to 15 mm or less is that if the stripes are wider than this, if you add a protrusion with the same width as the width w of the vertical stripe during preforming, the rigidity of the protrusion will be increased. This is largely because the protrusions themselves may be restrained by the vertical grooves of the roll in the final rolling pass, and the meandering of the strip may be restrained.

The limit value of this condition is not fully understood, but as shown in the numerical example, currently manufactured products are within this size range, so the maximum value confirmed through experiments was set as the limit. In other words, if the width w of the protruding thick part 7 is smaller than 15 mm, even if the thick part in the preform cross section enters the vertical striped groove of the final rolling roll, the width of the thick part is narrow and the rigidity is weak, so the belt cannot be Unable to restrain the meandering of the board,
It was experimentally confirmed that the method of the present invention needs to be applied.

The height Δt of the protruding thick-walled part of the product was set to 2 mm or more because vertical stripes with a height of 2 mm or less can be formed only by forming the final rolling pass, so there is no need to apply the method of the present invention. It is.

The width of the thick part in the preformed cross-sectional shape is (w/
3) The reason for setting the width to be more than +10 mm is because with current strip rolling technology, even if sufficient care is taken during rolling, it is unavoidable that the strip will be rolled with a meandering width within a range of ±5 mm. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1a and 1b. This example will be explained using experimental results using a rolling roll having a diameter of 250 mm. However, the rolling rolls in actual production machines are even larger, so
Below, we will show an example of numerical values calculated when all geometrical conditions are doubled and the diameter of the rolling roll is 500 mm.

As shown in Figure 1b, the intended cross-section of the product is a vertical stripe with a protruding thick part with a width of 7 mm.
However, five pieces are lined up in the width direction with an interval b=40 mm. The width of the strip plate is B = 320 mm under the experimental conditions, but if the width is wider, the number of vertical stripes will increase, but there will be no difference basically. There are various plate thicknesses, but as a representative example, the average plate thickness h is approximately 8.6.
The results are shown for mm strips. In this case B/h
The value of is approximately 37. Steel heated to 1000°C and lead at room temperature were used as rolling materials, but the results were almost the same, so the experimental results for lead at room temperature are shown.

In order to obtain the product cross-sectional shape as described above, a substantially uniform strip having a thickness of 20 mm was rolled in one pass and preformed into a cross-sectional shape having an average thickness H=13 mm as shown in FIG. 1a. The generatrix shape of the roll in this preform rolling was a cosine curved roll shape with a pitch b = 40 mm and a total depth of 4 mm. Corresponding to this roll shape, the preformed cross section had a maximum thickness difference of 4 mm between the thick part 5 and the thin part 6, as shown in the figure. Since the preformed cross-sectional shape has a cosine curve thickness distribution, the width of one vertical stripe that is thicker than the average sheet thickness is in the range of 20 mm, and this value is the predetermined vertical stripe width w = It is 17.7mm wider than 1/3 of 7mm.

In addition, as a comparative example, a roll with vertical striped grooves of width 11 mm and depth of 6 mm was used, and the average thickness H = 13
Further preparations were made that had been preformed to a size of mm. In this case, the width of the thick part in the preform cross section is only 8.7 mm wider than 1/3 of the predetermined vertical stripe width w = 7 mm of the product, so the influence of meandering of the plate is greater than in the method of the present invention. It is easy to receive and insufficient. In addition, the height of the stripes in the preformed cross section at this time was 3.6 mm,
It can be seen that the 6 mm deep groove is not sufficiently filled.

Now, the strip preformed using the method of the present invention and the strip preformed using the unsatisfactory comparative method were rolled using rolling rolls of the same type. In order to obtain the cross-sectional shape of the product shown in Figure 1b, the rolling rolls at this time were provided with grooves of 7 mm width and 6 mm depth along the circumferential direction, and the gap between the upper and lower rolling rolls was The average thickness h is 8.6mm
I adjusted it so that

When the strip is bitten by the rolls in such a final rolling pass, the thick part 5 in the preform cross section is aligned with the vertical striped grooves of the rolling rolls. The strip becomes oblique when viewed from above, and as rolling progresses, the position of the thick part in the preformed cross section and the position of the longitudinal grooves of the rolling rolls are shifted from each other in the width direction. The meandering amount δ in the width direction at this time can be determined by measuring and correlating the positions in the width direction of the thick portion before and after rolling.

Figure 7 shows the height of the vertical stripes in the product when the meandering amount δ between the thick part of the preformed cross section and the vertical striped groove of the final rolling roll changes in the above-described embodiment of the present invention and comparative example. This figure shows how the value Δt changes. As shown in FIG. 7, when the meandering in the width direction is small (δ5 mm), a vertical stripe height of Δt=5 mm or more is obtained in both the example and the comparative example. It can be seen that preforming can significantly increase Δt compared to the conventional rolling method that involves forming only the final rolling pass, which could only obtain Δt=3.0 mm or less for this size. However, when the meandering amount δ in the width direction increases, Δt suddenly starts to decrease from around δ = 5 mm in the case of the comparative example where the width of the thick part of the preformed cross section is narrow.
When δ=8 mm or more, the effect of preforming is almost lost. On the other hand, according to the embodiment, the height of the vertical stripes can be made sufficiently large even if the strip meanders by about δ=8 mm.

As described above, in this embodiment, even if there is a meandering of the strip of about δ=±8 mm, it is possible to form sufficiently high vertical stripes. Also in the comparative example,
The width of the thick part in the preformed cross section is 8.7 mm wider than 1/3 of the width of the vertical stripes of the product, so δ =
Meandering of strips of 4.4 mm or less is not a problem, but meandering of δ = ±5 mm or more is unavoidable in rolling operations for wide strips, and this comparative example is insufficient to stably obtain high vertical stripes. It is something.

In this example, the shape of the preformed cross section was a periodic cosine curved cross section as shown in FIG. This was to avoid patterns that would appear on the surface of the product when rolled, and it was easiest to specify the dimensions when giving a preformed cross section with a gentle thickness distribution. This is what I chose. The shape of the preform can be selected as appropriate within the basic idea of increasing the thickness near the vertical stripes of the product. In addition, as shown in Figure 1a, the preform cross section has thick-walled parts even in areas where vertical stripes are not formed on the product. This is because rolls of the same shape can be used in common as rolling rolls, and there is almost no effect on the thickness distribution of the uniform thickness portion of the product.

〔Effect of the invention〕

As explained above, the rolling method according to the present invention includes:
During rolling before the final rolling pass of the strip, at the position where the protruding vertical stripes are to be formed, the strip is formed in advance over a width wider than the width of the vertical stripes and is thicker than the average thickness. Since the vertical stripes are formed using a roll with predetermined vertical stripes carved in the final rolling pass, it is possible to effectively form taller vertical stripes on the surface of the wide strip plate than ever before. Even if the strip meandering occurs during normal operation, vertical stripes of uniform height can be obtained.

[Brief explanation of drawings]

1a and b are embodiments of the present invention, a
2 is a sectional view showing an example of a strip plate having vertical stripes, and 3 is a sectional view of each product.
The figure is a front view showing the roll shape of the final rolling pass, FIG. 4 is a schematic cross-sectional view explaining the conventional rolling method, and FIG.
Figures a to d are schematic cross-sectional views illustrating the positional relationship between roll grooves, thick-walled portions, and vertical stripes in a conventional rolling method; Figures 6 a and b are schematic side sectional views illustrating the principle of the present invention; FIG. 7 is a drawing showing the influence of the meandering amount of the plate on the vertical stripe height. 1, 2...Rolling roll, 3...Vertical striped groove, 4...
...Empty hole, 5...Preformed protruding thick wall part, 6
...thin wall part, 7,7'...vertical stripe, S...band plate,
δ...Amount of meandering.

Claims (1)

[Claims] 1 A wide strip plate having a predetermined plate width and a ratio of plate width to average plate thickness of 25 or more is rolled in multiple rolling passes, and is composed of two upper and lower rolling rolls. During the final rolling pass in which predetermined vertical striped grooves are cut into one roll, protruding vertical stripes with a width of 15 mm or less and a height of 2 mm or more are formed at predetermined positions in the width direction of the wide strip. In a rolling method in which a protruding vertical stripe is formed in at least one or more places almost continuously, a strip with a width larger than 1/3 of the width of the vertical stripe is formed at a position where a protruding vertical stripe is formed in the rolling process before the final rolling pass of the strip. at least
A method for rolling a wide strip plate having vertical stripes, characterized in that the strip plate is formed to have a thickness thicker than an average plate thickness over a wide width of 10 mm or more, and then the final rolling pass is performed.