JPS6297711A - Method for preventing edge drops in rolling - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application 1) The present invention relates to a method for controlling a plate profile in the rolling process of metal plates such as thin plates and thick plates made of steel, aluminum, etc.

(Prior Art) In the rolling process of metal materials, there is a problem called edge drop, in which the thickness of the edge portion of the rolled material decreases. This is because the elastic deformation of the roll (flattening of the roll) changes rapidly at the end of the rolling material contact area.

The edge drop can be reduced by alleviating the rapid deformation of the roll at the edge position, but the following method is known as a means of preventing edge drop of the rolled material in equipment that has the function of shifting the work rolls. It is being

(1) A method in which one end of the work roll is ground into a teno groove shape and the work roll is shifted so that a part of the chi A coincides with the end of the plate of the material to be rolled (Japanese Unexamined Patent Publication No. 55-77903, etc.) J.

(2) Furthermore, a method of applying bending t to such one-end tapered roll using a bending device to increase the effect (Japanese Patent Laid-open No. 5
4-118364, etc.].

In all of these, edge drops can be reduced by processing the edges so that the roll shape escapes.

(Problem to be Solved by the Invention J) However, in either case, it is necessary to process one end of the roll in advance into a Teno groove shape, which makes the polishing work of the roll complicated, and at the same time, Due to roll wear, the shape of a part of the chi A becomes disordered, and the effect becomes less effective.

In order to eliminate a series of such problems, the present invention focuses on the wear pattern of the rolls, and the present invention has been developed to eliminate the need for pre-processing the rolls into a special shape such as a tapered shape, and to prevent the rolling process from weakening as the rolling progresses. This method realizes a method for effectively reducing edge drops.

(Means for Solving Interval Points) In the present invention, when rolling a plate material by shifting the upper and lower work rolls in the axial direction, the position of a recess formed in the roll during rolling of the rolled material is determined, and the next rolled material is This is an edge drop prevention method characterized by aligning one of the recesses of the upper and lower rolls during rolling of the previous rolled material with both edge portions of the roll.

(Function) The present invention focuses on development in which the form of roll wear and thermal expansion becomes exactly partially tapered, and by utilizing this, the roll can be ground into a special shape (tapered shape). This is based on the fact that edge drop can be reduced without having to keep the edge drop.

The present invention will be explained below.

Normally, the wear A-turn of a roll has a peak around the edges and edges of the rolled material, as shown in Figure 1. This is because the metal flow at the edge is different from that at the center of the strip (or in the case of hot rolling, the temperature at the edge of the strip is lower than that at the center of the strip, resulting in a higher load on the roll at the edge). ], and furthermore, it is thought that this is because the amount of expansion of the roll due to the heat received from the material to be rolled is greater at the center of the strip than at the ends of the strip.

Utilizing this phenomenon, in order to reduce edge drop, in order to create a chi-shaped or e-shaped shape on the work roll in advance,
For example, a roll shift is performed using the following method.

Among the materials rolled between roll changes, focus is on the narrowest material. Its width is 1) min,
Furthermore, it is assumed that the roll shift is JliS determined by the equipment. Now change the rolls and change the width of the material to be rolled i-1st.
1, the shift amount Wa executed during the i-1th rolling
H,1 is determined by the following equation.

WS; -s= (bmin+s l-ψi -+ (However, WSi-!≧0) This means that the same parts of the upper and lower rolls should fit against the temporary edge. This means creating a tapered shape in advance.

Figure 1 (a) shows that after rolling a material with a material width bi-1, b
An implementation image is shown when attempting to roll a material with a width of i. In this case, a mechanism for reducing the edge drop of the material by utilizing the already created partially tapered shape is shown in FIG. 1(b).

(Material of the material Cbi width)) Obtain the partial tenor 7 part generated before rolling online by actual measurement or prediction calculation of flattening, and when the material is rolled down, apply this tenor 7 part to the edge part of the material. It is shifted and rolled so that they match.

(Implementation row) FIG. 3 shows a system configuration in which the present invention is implemented in a finishing tandem rolling mill of a hot strip mill.

This is shown for the i-stand of a tandem rolling mill.

Furthermore, the rolling results and the roll information obtained from the roll diameter information input device 8 are inputted to the roll profile calculation device 7 to accurately determine the local profile of the contact portion between the roll and the plate edge. Based on this result, the optimum work roll shift amount calculating device 9 determines the optimum shift amount from the information regarding the material width obtained from the next material rolling information input device 12 and the schedule information input device 13. The shift amount determined in this manner is stored in the next material presetting buffer 10, and is executed by the roll shift device 11 immediately before rolling the next material.

This series of operations is executed from role reshuffling to role reshuffling. Note that when changing roles, the role profile is initialized to match the role that will be installed from now on.

A train in which the present invention is applied to a hot strip mill finish rolling operation is shown in FIG.

The broken line in the figure shows a single trapezoidal roll, and the solid line shows a comparison in which the edge drop was reduced under almost the same material conditions by washing with water, thereby reducing the crown of the rolled material. As the number of rolls increases (after 40 to 50 rolls are rolled), the crown reduction due to edge drop reduction is more remarkable when washing with water compared to using a single trapezoidal roll.

(Effects of the Invention) As described above, by washing with water, edge drops can be reduced without requiring any special roll shape, and thereby a low crown of the rolled material can be achieved.

[Brief explanation of drawings]

1 and 2 are diagrams showing the relationship between roll wear and roll shift for explaining the present invention, FIG. 3 is a rolling control block diagram to which the present invention is applied, and FIG. 4 is a diagram showing the effects of the present invention over the conventional FIG. 1... Rolled material, 2... Work roll, 3... Width meter,
4...ffl & total, 5...N, total, 6...load cell, 7...roll profile calculation device, 8...rolling record and roll diameter information input device, 9...optimum work roll shift Quantity calculating device, 10... Nonotufa for presetting next material, 11... Work roll shift device, 12...
- Next material rolling information input device, 13... schedule information input device. Agent Patent attorney Masamitsu Aki Sawa and 2 others ~ 目α）
rrs voluntary procedure amendment November 28, 1985, L-f

Claims (1)

[Claims] (1) When rolling a plate material by shifting the upper and lower work rolls in the axial direction, find the position of the recess that occurs in the roll during rolling of the rolled material, and then apply the position of the concavity created in the roll during rolling of the rolled material to both edges of the next rolled material. An edge drop prevention method characterized by aligning one of the recesses of the upper and lower rolls.