JPH01284404A - Method for rolling steel stock by taper roll shift - Google Patents

Abstract

PURPOSE:To improve crown amounts and crown amount reducing amounts and to surely establish schedule-free rolling by installing at least 2 taper roll shift rolling stands and changing respective shift amounts within a range by which a sum of the respective shift amounts equals to a prescribed amount. CONSTITUTION:At least two taper roll shift rolling stands are installed. In the stands, upper and lower work rolls 2, 3 whose one end is formed into a tapered shape are positioned so that the tapered parts are oppositely located in right and left positions to each other and the rolls 2, 3 are shifted into opposite directions every rolling tie or every an optional number of rolling times so that both edges of a steel stock 1 locate in the tapered part on a basis of a taper starting point changing in accordance with wear of the rolls 2, 3. Respective shift amounts of the rolls 2, 3 are changed within a range by which a sum of shift amounts of the two stands equals to a prescribed amount. Hence, wear of the rolls 2, 3 and thermal crown amounts over the total width of the stock 1 are uniformized and crown amounts and crown amount reducing amounts are improved, so that stable schedule-free rolling is established.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is characterized in that upper and lower work rolls each having a tapered portion at one end are arranged so that the tapered portions are on opposite sides, and the upper and lower work rolls are placed relative to each other. In this method, the crown amount Cps, which indicates the difference in plate thickness at a point 25+l1m from the widthwise center and both side edges of the steel material after rolling, is reduced, and the crown amount of conventional rolling is reduced by a taper roll. Crown amount reduction amount ΔC improved by shift rolling
The present invention relates to a strip rolling method in which schedule-free rolling is possible by smoothing out either or both wear and thermal crown while increasing the number of strips.

<Prior Art> Making the cross section of a steel plate rectangular in the sheet width direction improves the product yield, and the development of effective and practical means continues.

Normally, the thickness of a rolled steel plate suddenly decreases at both ends in the width direction, and this is generally referred to as edge drop.

The plate thickness deviation in the plate width direction of the product is controlled by the crown amount CZS described above, including the edge drop described above, and the structure, operation, and effect of the present invention will be explained below in the same manner.

The edge drop described above occurs because the work roll is deformed and flattened at the roll bite part where the work roll is in contact with the steel material in the soil, and the degree of flattening changes rapidly near both ends of the steel strip in the width direction. It is considered to be.

In recent years, the uniformity of thickness distribution in the width direction of rolled steel strips has improved markedly, but this has not yet met the demand, and there is still a strong demand for steel materials with a small crown IC25, in other words, extremely low crown materials.

In response to this demand, methods for reducing the rolling edge of the work roll for the purpose of reducing the amount of flattening include, for example, reducing the diameter of the work roll, and rolling with light rolling in the latter stage to form the shape (first stage loading type). .

However, each method has its own issues, and the reality is that they are still only used in specific fields.

Currently being considered in the field of steel rolling, a tapered part is formed at one end of the work roll, and the tapered parts of the upper and lower work rolls are arranged oppositely on the left and right, and the upper and lower work rolls are placed relative to each other. This is a rolling method in which the material is shifted in the axial direction.

Furthermore, recently, a so-called schedule-free rolling technique, which is a technique for smoothing the wear of work rolls even when the width of the copper strip changes, has been attracting attention, and efforts are being made to make it compatible with the technique for reducing the crown amount Czq.

Currently, the methods that correspond to these are as follows: (hereinafter expressed as absolute shift amount and Sakaki width W) is first set, and rolling is performed while maintaining the side edge position of the steel material without changing the side edge position for the above-mentioned (hereinafter referred to as above) (Japanese Patent Laid-Open No. 55-77903) (2) In the improvement method of (1) above, the Taper start point cue at the completion of grinding of the work roll is corrected based on the wear caused by rolling the steel strip, and the corrected taper start point D1 and the side of the steel strip. A rolling method in which Wt, which adds the distance from Do to DI to a constant distance #i (hereinafter expressed as effective shift amount and W) to the end, is used in the same way in subsequent rolling.

(Proposal in Japanese Patent Application No. 1597/1983) (3) To prevent both ends of the a band from coming off the tapered portion of the rolling roll, the effective shift amount W is set to 100 to 200 a+m.
The so-called oscillation rolling method changes the absolute shift iwt every rolling. There are proposals such as (proposal of Japanese Patent Application Laid-open No. 110401/1983).

In addition, W mentioned here is a case where it remains unchanged from the initial setting as in (1), a case where it changes according to wear of <06 as in (2), and a case where both ends of the steel strip are rolled by rolling rolls as in (3). There are cases where it changes depending on the oscillation that is performed to prevent it from coming off the tapered part.

<Problems to be Solved by the Invention> However, if the rolling method described in item (1) above is used continuously, the effect of reducing the edge drop value will be reduced due to wear of the work rolls, especially roll wear near the Taber start point (hereinafter expressed). , starts to decrease immediately after rolling starts, and eventually loses its effect completely.

In addition, as shown in Figure 11, the wear of the work rolls after rolling several tens of rolls results in a steep point Z in the roll profile, and as is clear from the figure, no roll shift effect can be obtained, making application to continuous large-volume rolling difficult. Can not.

Furthermore, when the rolling method described in (2) above is used continuously, the roll profile due to wear of the work roll is smooth without any steep points Z on the roll profile, as shown in FIG. Although the reduction effect continues, better smoothing of the wear and/or thermal crown is desired.

When the rolling method described in (3) above is continued, the wear condition of the work roll after rolling several tens of rolls becomes as shown in Fig. 13, which is smoother than in (1) above, but will be described later on page 11. If a large effect is sought by increasing the taper angle θ or by increasing the width of the steel material facing the tapered portion, or by doing both, large variations in the effect will occur and the effect will gradually disappear.

For example, if the taper angle θ is increased to tanθ-2, OXl0-' and the absolute shift amount Wt is periodically oscillated every time the steel strip is rolled to achieve a schedule-free effect, the crown amount C25 depending on the number of rolled strips is As shown in Figure 10, the effect varies greatly in the early stages,
This effect gradually disappears, and the crown amount C25 finally exceeds the allowable range.

In any case, the above-mentioned effect is lost, so there is a limit to the number of rolls that can be rolled per unit of low-crown material, making it impractical.

As mentioned above, based on taper roll shift rolling,
A rolling technique that achieves both the crown amount CZS reduction effect and the schedule-free effect has not yet been established, and the object of the present invention is to establish this.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides the following features: (1) Each tapered part of the upper and lower work rolls having a tapered part formed at one end of the roll is positioned on opposite left and right sides, and the tapered part of the work roll is A tapered roll that shifts the upper and lower work rolls in a relative direction every rolling or every arbitrary number of rollings, based on a taper starting point that changes according to wear, so that both side edges of the steel material are always located at the tapered part. In the method of rolling the steel material using a shift rolling stand, at least two of the tapered roll shift rolling stands are arranged in a range where the sum of the shift amounts of each stand is a predetermined amount,
The first means is to change the shift amount of the work roll, and (2) the Taber angle, effective shift amount, and rolling reduction rate of each work roll in each tapered roll shift rolling stand reduce the crown amount on the exit side of the final stand. The first step is to set the Taber angle, effective shift amount, and rolling reduction rate of each work roll so that the influence coefficients on the amount ΔC25 are equal.
(3) The range of changing the shift amount in each tapered roll shift rolling stand is made equal to the first and second means.
(4) Adding to the first to fourth means that the above-mentioned at least two tapered roll shift rolling stands are arranged in succession. and (5) adding to the first to eighth means that the tapered roll shift rolling stand is the second rolling stand before the final stand of the tandem rolling mill. This is the 16th means.

Effect> In order to solve the above problem, the inventors of the present application repeatedly conducted various experiments by arranging one tapered roll shift rolling stand at the rear stage of a tandem rolling mill consisting of seven stands.

The outline of the tapered roll shift rolling stand used by the inventors in the above experiment will be explained using FIG. 4.

1 is the steel material to be rolled, 2 is the upper work roll, 3 is the lower work roll, 4 is the upper and 5 is the lower work roll, 6 is the upper spindle, 7 is the lower spindle, 8 is the upper, 9 is the lower These are reinforcing rolls that support each work roll, and 10 is a chock for the upper reinforcing roll, and 11 is a chock for each of the lower reinforcing rolls.

The work rolls 2 and 3 have a tapered portion whose diameter gradually decreases at one end in the axial direction, and each of the upper and lower work rolls 2.3 has a tapered portion such that the tapered portions are in opposite positions. are disposed in opposite directions, and are supported by work roll sinks 4 and 5 so as to be shiftable in the roll axis direction.

Although the shift devices for work rolls 2 and 3 are not shown,
A known one was used.

Although not shown in the drawings, a roll bending device is installed to apply both increase and defreeze pending forces to the work rolls in the same way as in a normal rolling device.

FIG. 5 is an enlarged view of the vicinity of the Taber starting point of the work roll shown in FIG. 4, and C is the center of the barrel portion of the work roll. Also, Do indicates the initial Taber starting point, and A indicates the above C.
is the Taber starting point distance indicating the distance between and 00. The angle θ formed by the extension of the barrel portion of the work roll and the Taber portion is called the Taber angle and is expressed by the value of tan θ.

There are the following two Taber starting points.

One of them is to take the initial Taber start point which is the Taber start point at the time of completion of grinding as shown in FIG. 1
One is, as proposed in the above-mentioned Japanese Patent Application No. 1597/1983, as the steel strip is rolled after work rolls are rearranged, the actual Taber start point continues to shift toward the Taber end point due to roll wear;
That is, this is the case where the correction Taber starting point DI is taken.

Therefore, the above-mentioned absolute shift) amount wt is the distance between the side edge of the rolled material and the above-mentioned Taber starting point Do, and the above-mentioned effective shift)! wi is the distance between the side edge of the rolled material and the Taber starting point D1.

The present inventors used the rolling stand described above to establish a rolling method that solves the practical problem of the prior example (2), by combining the preceding examples (2) and (3). We experimented with rolling methods.

The results will be explained using FIG. 6.

FIG. 6(a) is a diagram illustrating the movement of the Taber start point relative to the side end position of the rolled material when it is aligned with the side end position as a reference in a case where the preceding examples (2) and (3) are combined.

■ indicates the state of the first roll after work roll rearrangement.

At this time, the situation is the same as that proposed in Japanese Unexamined Patent Publication No. 55-77903.

A is the initial taber starting point Do from the roll center C at this time.
It represents the starting distance up to Taber.

(2) shows the state of W when several steel materials are rolled and the amount of oscillation is 0.

At this time, the surface of the work roll (2) above has disappeared due to roll wear, and is therefore indicated by a dashed line in the figure.

The corrected Taber start point in ■ is the Do in ■ moved to the left in the figure by the distance L'd B + to Dl, and the figure represents the side edge position of the rolled material whose position changes each time it is rolled. Zuni,
Since the side edges of the rolled material are shown aligned as a reference, the center position of the work roll B is shown to have moved to the left.

■ is after rolling more than 10 rolls, and the amount of oscillation is O
This shows the state of Wt when ing.

From the above, the present inventors have found that when shifting the upper and lower work rolls toward the anti-Taber portion side each time rolling, if an oscillation shift is performed by adding a shift amount of B or 82, the effect on the corrected Taber start point DI and B2 is The shift amount W8 is always maintained at a predetermined amount, stably and smoothly shifting to the target C25.
and ΔC25 can be obtained.

The proposal of Japanese Patent Application Laid-open No. 55-77903 is based on this Do
81 and B2 have been changed to Dl and B2, so when B becomes larger than the effective shift amount, the side edge of the steel material no longer exists in the tapered part of the upper or lower work roll, and the 11th This results in the results shown in the figure, making it impossible to continue tapered roll shift rolling.

FIG. 6(c) shows the prior example (3) independent shift method and (2)
) and (3) are combined, and both shift rolling methods based on the knowledge shown in FIG. 6(a) are shown in rolling order.

This Fig. 6(C) shows a situation in which the width of the rolled material decreases by 2X on the way with the roll center C as the reference line, contrary to Fig. 6(a) for a work roll having a tapered portion on the right side. It shows.

In the preceding example (3) shown by the broken line, the initial taper start point is from the center C of the taper work roll until the temporary width change.

The distance MA is constant, and the position of the side end of the rolled material is represented by a broken line, and the broken line is the position of the initial taper start point DO plus a predetermined oscillation shift for each group.

Therefore, at the board width change point, the roll is moved to 1/1 of the board width change point.
Since it is shifted to the left in the figure by X, which corresponds to 2, the center C of the roll is also the initial taper starting point.

is also shifted to the left side in the figure, and thereafter the work rolls are shifted in the same state as before the sheet width change point.

On the other hand, in the combination of precedent examples (2) and (3) shown by the solid line, the corrected taper starting point DI-n sequentially moves to the right side of the figure as the number of rolled pieces increases, so the position of the side edge of the rolled material shown by the solid line is the initial taper start point Do plus the aforementioned Bl-n and a predetermined oscillation shift for each group.

At the board width change point, the roll is shifted by X to the left in the figure as in the prior example (3), and thereafter the same roll shift as before is repeated.

Therefore, when the rolled material in (b) is completely rolled, in the preceding example (3) alone, the side end position of the rolled material is always at the point WL in (3) above tenths from the roll center C, and in the preceding example (2
) and (3), the rolled material side end position is at the position A+B+W, -A+ (W of the above (2) + above (3)) from the roll center C.

Next, the characteristics of tapered roll shift rolling were analyzed using the above rolling mill by varying the effective shift amount W1 and the Taber angle θ, and the results shown in FIG. 3 were obtained.

In the figure, tan θ=1.0X10" is marked 0, and ta is marked .
The experimental value of n θ・1.6×10″1 is entered.

As is clear from the figure, the larger the effective shift amount W, the larger the crown amount reduction amount ΔC2-1, and the larger the taper angle θ, the larger the crown amount reduction amount ΔC.
ps increases.

This rolling characteristic is not limited to the stand position (for example, the fifth or sixth stand) of the tandem rolling mill, and shows the same tendency in any stand, although there are differences in effectiveness.

However, the absolute value of the influence coefficient of the Taper angle, effective shift 1w, and rolling reduction rate on the crown amount reduction amount ΔCtS varies somewhat depending on the position in the tandem rolling mill of the stand where the tapered roll shift rolling stand is installed. In doing so, we found that it is necessary to select the most efficient location by looking at the overall effect from the aspects of economy, productivity, and operability.

Therefore, the inventors of the present application reduced the crown amount Ct%,
Based on the above experimental data and rolling theory, we have devised various ideas to increase the crown amount reduction amount ΔCzs to enable rolling of extremely low crown material, and to simultaneously perform schedule-free rolling that allows continuous mass rolling. Ta.

One of them is to install tapered roll shift rolling stands in multiple stands of a tandem rolling mill, and to set the effective shift IW in each tapered roll shift rolling stand,
I tried to use them complementary to each other.

The results will be explained using FIG.

The figure shows a case where tapered roll shift rolling stands are installed in the fifth stand (hereinafter referred to as F5) and the sixth stand (hereinafter referred to as F&) of a seven-stand tandem rolling mill.

Taking the crown amount reduction amount ΔC25 on the vertical axis and the effective shift) LtW on the horizontal axis, the effective shift amount W of F6 is O ~
100n+m, and vice versa.

If we take the Ws of 100 to OIl in correspondence, the independent characteristics of Fs and F become opposite trend characteristics as shown by the two broken lines, and the effects of F and F6 can be evaluated using the characteristics of the influence coefficient. When combined, the result shown by the solid line is obtained, and Fs
When the effective shift (IW) of F6 was between 0 and 10011 m, the crown amount reduction amount ΔC25 was a substantially constant value of 30 μm.

The second study organized the rolling characteristics in relation to the number of rolled sheets.
It is a diagram.

Fig. 2 (a) shows the characteristics of crown crab reduction ΔC25 when tapered roll shift rolling is performed with Fs and F6 alone, and the solid line shows the effective shift amount W of Fs, starting from the Oim point and sine up to 100++ue. This is a schematic representation of the individual characteristics in the case of a wave-like periodic shift. The broken line is F
Starting from the 100ms point, the effective shift amount W of 6 is Om.
This diagram schematically shows the individual characteristics when the waveforms are periodically shifted in a cosine wave shape up to m, and each vibrates at 30 μm.

On the other hand, ■) represents the final stand exit side, that is, the ΔC25 of the steel material after rolling, when the effective shift NWs of F and F6 are shifted in a complementary manner in a sine wave shape and a cosine wave shape from 0 to 10 shaft openings, respectively. The vibration was much smaller at 5 μm.

Here, to make the effective shift amounts W3 of a plurality of stands act complementary to each other means to make them act in balance with each other, in other words, to maintain a predetermined relationship.A typical example is that each effective shift amount Ws The sum of the sum is a predetermined amount.

For example, in the case of FIG. 1, the sum of the effective shift amount W8 of F5 and the effective shift amount W of F6 is always a predetermined amount of 1001111.

In addition, when three tapered roll shift rolling stands are installed, they can be rotated at 120° from each other, such as in the dynamic waveform of a three-phase alternating current.
It is sufficient to move the effective shift (fftW) in a sinusoidal waveform in which the phase is shifted while maintaining the phase difference of .

Further, the maximum point of the effect of the predetermined amount is one point, but in practice, even if there is a slight deviation, the effect will not change much, so in practice it is sufficient as long as it is within the predetermined range.

The present inventors have determined that, from the relationship shown in FIG. 1, the influence coefficient on the crown bite reduction amount ΔC2% with respect to the effective shift amount Ws is
It has been found that when F5 and F6 are equal, the effect of the present invention by combining them is maximum (the amount of variation in ΔC25 is minimum). In accordance with this, it is preferable to make the range of variation of the effective shift amount of each tapered roll shift rolling stand the same as it is easy to implement and stable. Furthermore, it has been learned that it is preferable to install the tapered roll shift rolling stand continuously in the tandem rolling mill, and that it is preferable to install the tapered roll shift rolling stands close to the final stand during hot rolling. The rolling engineer may arbitrarily select whether to install a tapered roll or a flannel roll on the final stand, and whether to make the backup roll of the tapered roll flat or crowned. There will be no change in the operation or effect of the invention.

Based on the above facts, the present inventors have determined that during hot rolling, at least two consecutive rolling stands before the final stand,
It has been found that application of the present invention satisfies the above-mentioned demands, has great effects, and has excellent operability.

<Example> A typical example in which the present invention is applied to a hot tandem rolling mill will be described below.

This example is an example in which a 7-stand hot tandem rolling mill whose equipment specifications are shown in Table 1 was used, and the above-mentioned taper roll shift rolling stand shown in FIG. 4 was inserted at the rear stage to roll a steel material.

The dimensions of the rolling rolls at that time are shown in FIG.

- Barrel length 2400a+m - Taper length 30f) am - Roll diameter D710-800+nm - Taper angle θ (listed in Table 2) - Diameter at the tip of the tapered part d d = D -2x300 Xtanθ (mm) In addition, the initial stage of each rolling roll The crowns were all flat.

The results of crown profile control of steel materials according to the present invention are shown below.

An example of the present invention will be explained in comparison with a conventional tapered roll shift rolling method.

(Example 1) The tapered roll shift rolling stands were placed at F and F6.

The Taber angle θ and effective shift of the rolling rolls F and F6 were determined as shown in Table 2.

In this example, the predetermined amount that is the complementary addition of F and the effective shift amount W of F6 is set to 100 mn.

As shown in Table 3, the shift pattern was such that each steel material was shifted by an arbitrary shift amount each time one steel material was rolled, and a group of six steel materials was formed.

The conventional rolling method was carried out in the same manner as in the example of the present invention by installing flat work rolls (the first progeny crown is also flat) in all stands of the tandem rolling mill shown in Table 1.

The conditions shown in Table 4 were used for the steel type, dimensional conditions, and rolling/temperature conditions of the steel material.

The results of rolling according to the present invention are shown in FIG. 8 together with the results of the conventional rolling method.

As is clear from the figure, the profile of the rolled steel material in the sheet width direction has a crown amount C25 of 20μ in the rolling method of the present invention.
1, and in the conventional rolling method it was 60μ, and the effect of the example of the present invention was remarkable.

Further, as shown in FIG. 9, the value of the crown amount C2S of the present invention is stable for each rolling, and the fluctuation value of the crown ICzs due to the influence of shift amount fluctuation is as small as 20IIIl.

The effect of the example of the present invention becomes even clearer when comparing FIG. 9 with FIG. 10, which shows the results of shift rolling using a single tapered roll shift rolling stand.

(Example 2) As in Example 1, the taper roll shift rolling stands were arranged in two stands F5 and F6, and the respective taper angles, ranges of effective shift lit, and predetermined amounts of the sum of each shift i were also implemented. The present invention was carried out using the same settings as in Example 1 and under the following conditions.

Number of rolls rolled (rolls) 12 group predetermined number (rolls) N-6x2 Roll wear fit per rolled material (μIII)
4 Upper limit of effective shift amount (+am) 10
0 Lower limit of effective shift amount (■) 0 First group effective shift) order of f (II+m) Fs:
Ws 1=20 Ws 2=60 Ws 3=1
00Fa: Ws 1=80 Ws 2; 40 W
s 3=OF5:Ws 4=so Ws 5=40
Ws 6=OFh:Ws 4=20 Ws 5
=60 Ws 6=100 Second group effective shift amount order (ms) Fs: Ws 1”20 Ws 2:
OWs 3=40F*: Ws 1”80 Ws 2=
100Ws 3=60Fs:Ws 4”80W
s 5; 100 Ws 6=60Fh: Ws 4”2
0 Ws 5=OWs 6=40 Deviation value (as) of the taper start point in the roll axis direction due to work roll wear during rolling 4 (-0,004/ (1,OXl0
) According to the above conditions, 12 pieces of rolled material were rolled into two groups, and the average product crown within the group was 35 (μm) for the inventive example and 60 (μm) for the conventional example.
μm), the example of the present invention was able to achieve the target extremely low crown.

(Example 3) The tapered roll shift rolling stands were arranged in the rear three stands F3, F6, and Fl.

The taper angle of the roll of each tapered roll shift rolling stand is set so that the influence coefficient of the crown amount reduction amount ΔC25 on the exit side of the final stand with respect to the effective shift amount is equal, and the possible range of the effective shift MI W s is also equal. It was determined as shown in Table 5.

Further, the predetermined amount that is the complementary addition of F5, F, and FT effective shifts (IJW) was set to 18.

The shift pattern of the present invention example was carried out as shown in Table 6 in the rolling order of each rolled material.

The steel type, dimensions, and rolling/temperature conditions of the steel material are as per Example 1 (
Same as Table 4).

As a result, in the example of the present invention, the crown amount CZS was further reduced to 10 am.

Furthermore, the variation range of the crown amount C25 for each rolled material was further reduced to 8 μm.

<Effects of the Invention> The present invention as described above performs taper roll shift rolling using multiple tandem rolling mills, which compensates for the movement of the taper starting point due to wear, and also makes it possible to smooth roll wear and/or thermal crown over the entire width. By complementarily performing the rolling between the stands, the crown amount C25 and the crown amount reduction amount ΔC25 are significantly improved, making it possible to establish stable schedule-free rolling that satisfies the above requirements. The industrial effects brought about in the rolling field are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram explaining the present invention in detail, and FIG.
) shows the characteristics of C25 in terms of crown amount reduction when tapered roll shift rolling is performed with F5 and F- alone, and (b)
is the effective shift iW of F5 and F&, respectively from 0 to 10
Figure 3 shows the crown amount reduction amount ΔCZS when a tapered roll shift rolling stand is used as one stand of a tandem rolling mill. FIG. 4 is a characteristic diagram showing the relationship between the effective shift view Ws and the effective shift view Ws. Figure 4 is a front view of the tapered roll shift rolling stand, Figure 5 is an enlarged view of the plate side end of the steel material and the vicinity of the taper start point of the rolling roll, and Figure 6 (a) (C) is the front view of the steel material. FIG. 3 is a comparison diagram of the relationship between the plate side end and the taper start point of the lower work roll, an example of changing the width of the rolled material, and the actual state of changing the width of the rolled material and each taper roll shift rolling method. Fig. 7 is a front view showing the dimensions of the tapered rolling roll of the tapered roll shift rolling stand, Fig. 8 is an actual measurement drawing showing the profile shape in the width direction of the steel material after rolling according to the present invention and the conventional method, and Fig. 9 is a It is a rolling progress diagram of crown amount C25 of this invention. Fig. 10 is a rolling progress diagram of crown amount C25 when one stand of a tandem rolling mill is provided with a tapered roll shift rolling stand, and Fig. 11 is a conventional example of JP-A-55
Fig. 12 is a cross-sectional view of the steel material and the roll showing the wear status of the roll when taper rolling is performed (Wt - constant) disclosed in Japanese Patent Application No. 1597-1983 as a comparative example. A cross-sectional view of the steel material and the roll showing the wear status of the roll when performing the proposed taper power crawl shift rolling while correcting the taper start point according to the wear of the work roll. Figure 13 is a conventional example of JP-A Showa 59
FIG. 2 is a cross-sectional view of a steel material and a rolling roll showing the state of wear of the rolling roll when oscillation rolling is carried out on the tapered roll shift rolling stand disclosed in Japanese Patent No. -110401. Patent applicant: Nippon Steel Corporation Agent: Masu Tegori (and 2 others) Figure 1 Figure 2 (a) (FS Fl,...------) Bottom latitude
→n (b) Bottom material →n Fig. 4 Fig. 5 Fig. 6: Engraving of upper spindle drawing (no change in content) Fig. 6 (b) (c) e Dyu Fig. 6 Fig. 7 Fig. 8 ( Dimensions: 2.0 'X840' ) Figure 9 (μm) (Example of the present invention) Figure 10 (□j) □ Missing Figure 11 Figure 13 Procedural amendments Working side August 25, 1988 Commissioner of the Japan Patent Office Yoshi 1) Moon Yi 1, Indication of the incident 1986 Patent Application No. 111993 B
Name of the invention Method for rolling steel materials by tapered roll shift 1 Relationship to the case of the person making the amendment Patent applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name
(665) Nippon Steel Corporation Representative M Fuji
Yu4, agent address ■812 Hakata Shin-Mitsui Building, 1-1-1 Hakata Ekimae, Hakata-ku, Fukuoka (092) 451-8781 Shipping date
July 2G, 1986 (contents of Kuchiyama;

Claims (5)

[Claims] (1) The tapered parts of the upper and lower work rolls, each with a tapered part formed at one end of the roll, are positioned on opposite sides, and both edges of the steel material are always aligned based on the taper starting point, which changes depending on the wear of the work roll. In the method of rolling the steel material using a tapered roll shift rolling stand that shifts the upper and lower work rolls in a relative direction every rolling or every arbitrary rolling number of times so as to be located in the tapered part, the tapered roll shifting rolling stand In the range where at least two stands are arranged and the sum of the shift amounts of each stand is a predetermined amount,
A method of rolling a steel material using a taper roll shift, characterized in that the shift amount of the work roll is changed. (2) The taper angle of each work roll is adjusted so that the influence coefficients of the taper angle, effective shift amount, and reduction rate of each work roll on the crown amount reduction amount on the exit side of the final stand are equal in each of the taper roll shift rolling stands. The rolling method according to claim 1, characterized in that the effective shift amount and rolling reduction ratio are set. (3) The rolling method according to any one of claims 1 to 2, wherein the range in which the shift amount is changed in each of the tapered roll shift rolling stands is made equal. (4) The rolling method according to any one of claims 1 to 3, wherein the at least two tapered roll shift rolling stands are arranged in series. (5) The rolling method according to any one of claims 1 to 4, wherein the tapered roll shift rolling stand is a second rolling stand before the final stand of a tandem rolling mill.