JPS5939404A - Temper rolling method with control for roughness of plate surface - Google Patents

Abstract

PURPOSE:To obtain a uniform surface roughness over the entire region in the rolling direction of a temper rolled plate by adjusting adequately rolling force according to rolling speeds. CONSTITUTION:The rolling speed signal of a strip 1 detected with a speed detector 3 connected to the work roll 2a' of the No.2 stand is converted by a signal converter 4. The converted signal thereof and the blank material conditions of the strip 1 as well as the rolling force signal fed from a rolling down force detector 8 with a converter 9 for rolling force signal are added and the rolling down force satisfying the relation P=f(V) (P; rolling down force, V; rolling speed) is calculated with an arithmetic device 5. The output thereof is amplified with an amplifier 6 and is delivered to a control mechanism 7 for rolling down force so that the strip is rolled under the prescribed rolling down force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temper rolling method for controlling plate surface roughness, and in particular, a method that is advantageously carried out to obtain a pressure regulating plate having uniform surface roughness over the entire rolling direction. This is a proposal about.

The surface roughness of cold-rolled steel sheets requires quality control in terms of die galling resistance during pressing, paintability, and solder rise during iron making, and has traditionally been controlled by the roughness of pressure regulating rolls. There is.

Generally, when observing a product after temper rolling, it is known that the roughness differs between the ends and the middle part in the longitudinal direction (rolling direction) of the strip. Therefore, from a quality assurance standpoint, conventionally, both ends and the middle part were roughly checked, and after confirming that both of them were within the target roughness tolerance range, the shipping case was shipped. A system was in place to send it to the bamboo plating process.

However, in order to implement such a system, it is necessary to
It was necessary to take sample plates at the IE rolling or the next process glue coiling line and measure the roughness, which forced the suspension of purchasing and pressure processing until the results were known. However, when this entrainment is carried out, there are drawbacks such as the occurrence of shape defects due to changes in the heat crown of the rolling rolls.

Moreover, the bigger problem with this stoppage is that when the roughness judgment comes out, it is decided whether to replace the rolling roll, change the rolling condition f: or continue as it is. After that, the work can be resumed, resulting in a significant loss of efficiency.

The purpose of the present invention is to propose a temper rolling method that can overcome all the shortcomings of the prior art described above. This technology is characterized in that a uniform surface roughness can be obtained over the entire area. The details of the configuration of the present invention will be explained below using preferred practical examples.

The present invention is based on the knowledge that there is a certain relationship between the temper rolling speed and the plate surface roughness (the downstream edge P is expressed by the width of the rolling speed WiP-f(V)). This is a quality rolling method.

Although the plate surface roughness during temper rolling is roughly determined by the surface finish of the work rolls used, research has revealed that it is greatly influenced by the speed of A quality rolling. For example, in A-quality rolling of Hl tinplate original plate, the speed difference is 1 in 2 stand one-hand temper rolling with prite finish.
It was found that there is a difference of 0,088 m (Ra) at 500 mpm. (The roughness becomes rougher when the rolling speed is high.) This is because the strain rate changes depending on the rolling speed, and as a result, the deformation resistance fluctuates, resulting in fluctuations in the rolling reduction amount.

It was assumed that this phenomenon was caused by fluctuations in the degree to which the work roll surface roughness was transferred to the plate surface, the so-called transfer rate. Therefore, it has been found that the non-uniform roughness in the longitudinal direction of the strip, which has conventionally been observed, can be resolved by controlling the rolling force in accordance with the rolling speed during temper rolling.

Next, a description will be given of how to control the -C plate surface roughness during temper rolling.

FIG. 1 shows the results of C-74 testing of roughness differences due to differences in rolling speed when flight-finished tin blanks were manufactured using a two-stand Chokahi rolling mill. As you can see from the figure above, there is a high rolling speed and an extremely low rolling speed (speed→
The roughness difference ΔHa(μ
There is a strong correlation between m) and the temper rolling speed v' (tnpm), and 71 can be expressed by a path equation. That is, ΔRa=(2X l 0-6)V...
... Song ... (1) Figure 2 shows the speed 150 (+
(mpm), the reduction edge per depression P (/, □) and the roughness reduction value Rλ [μm] were shown to have a close relationship, and a strong correlation was also observed, and the relationship between the two was It can be shown by the formula.

(0,5≦P≦1.5) ΔRa--0.08 (P-1,5) +0.08-・
-...-(2)) Here, assuming that ΔRa-ΔRa-0 approximately holds true, the above equations (1) and (2) can be rearranged as follows.

2X1(l V+0.08(P-1,5)-0,0&
= 0 ・(8) This equation (3) is solved for the downstream blade P as follows: Under the assumption that the above condition ΔRa - ΔRa - 0 is fully satisfied: In other words, the reduction, force and temper rolling speed to obtain a constant plate surface roughness over the entire rolling direction (longitudinal direction of the strip) are It can be said that it shows the relationship between the two. Figure 3 shows the opening of both of them as shown in equation (4).

It is something that

Next, an example is shown in Fig. 4 in which the above-mentioned FA quality rolling method to obtain a uniform plate surface roughness is carried out by controlling to maintain the relationship between speed and pressure shown in equation (4) above. I will explain. .

In the figure, 1 is a strip' which is the pressure material to be controlled; 2 is a two-stand tandem temper rolling mill; 2a and 2'a are its work rolls; and this rolling mill is equipped with a speed detector 8 and a downstream force detector 8. This is the provision. Now, to adjust the rolling blade for skin pass rolling to make the roughness of the strip l uniform over the entire area, the signal converter 4 converts the speed signal detected by the speed detector 3 connected to the A2 stand work roll 2. do. Then, by taking into account the signal regarding this speed, the material conditions of the strip l, and the rolling blade number fi sent from the rolling force detector 8 through the rolling blade number 16 converter 9, the arithmetic unit 5 calculates -
Using formula (4) in section h, calculate the appropriate rolling blade using the checkerboard shown in Figure 3, and amplify the output with the amplifying device 6 and output it to the rolling force control mechanism 7 to adjust the rolling blade to a predetermined rolling blade. Roll it.

FIG. 5 shows a comparison of the results of roughness control using this device W+ with the conventional method. Looking at this result,
The roughness difference between high speed and low speed according to the method of the present invention is 0.02μ
It is clear that the number of cases outside the target tolerance value has been significantly reduced, and the intended effect of the present invention has been verified as expected.

[Brief explanation of the drawing]

Figure 1 is a graph illustrating the influence of speed on plate surface roughness. Figure 2 is a graph illustrating the influence of rolling blades on plate surface roughness. Figure 8 is a graph illustrating the effect of rolling blade on plate surface roughness. 2. Drawing force setting curve diagram for keeping the rolling force constant; Figure 4 is a route diagram of the device for controlling plate surface roughness; Figure 5 shows the influence of the conventional method and the present invention on plate surface roughness. This is a graph for comparison. l... Strip 2... Temper rolling mill 2a,
2a'...Work roll 3...Speed detector 4...
- Signal converter 6... Arithmetic device 6... Amplifying device 7... Rolling force control mechanism 8... Rolling force detector 9... Downstream fN converter. Patent applicant: Kawasaki Steel Corporation Figure 1'2'E! Rf compression speed VC leaf lead 2 Width somah vertical pressure ゛FhP (tC54 Yahoo Figure 8 Osoo tooo tso. Training ash communication degree Cmprn) ;;) Figure 4

Claims (1)

[Claims] L The plate surface roughness during skin pass rolling is controlled by passing the plate so that the rolling speed V and the rolling blade P satisfy the relationship expressed by P - f (V), a function of the rolling speed,
A rolling method for controlling plate surface roughness, which consists of obtaining uniform plate surface roughness in the rolling direction.