JPH07195122A - Method for straightening bent roll - Google Patents

Abstract

PURPOSE:To straighten bent of a roll in on-line in a short time when a method is used when a steel plate is rolled or a billet is drawn. CONSTITUTION:A groove 2 is formed by gauzing a projecting side of the roll 1 in which a bent is generated by thermal stress. When the groove 2 is build-up welded, the welded part is applied with shrinking force and the bent is straightened and the original shape is recovered. For instance, 18.5kg build-up welding is executed for 1.2mm bent of a roll. Then, the surface of welded part is finished and working is continued without exchanging the roll. Accordingly, the bent of roll is straightened without exchanging roll in on-line in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of straightening a roll used for rolling a steel sheet or drawing a slab.

[0002]

2. Description of the Related Art A roll used for rolling a steel sheet or drawing a slab is bent for a long period of time due to thermal stress and other causes. In such a case, conventionally, it is removed from the line and the roll body is cut, or the roll surface is padded to finish the surface to correct the bend and reused.

[0003]

However, the conventional roll bending correction method has the following problems. The curled roll has a smaller diameter because the body is cut to correct the curving, and the diameter is increased when the surface is padded and straightened by finishing. In addition, when the rolls on the line are bent and they are straightened, they have to be removed from the line. Due to the above-mentioned problems, the conventional method is costly and labor-intensive, and the operating efficiency is inevitably lowered.

The present invention solves the problems of the conventional method,
Since there is no cost and labor, the operating efficiency does not decrease, and the roll diameter does not change, it is an object to provide a roll bending straightening method which can be reused as it is without replacing the roll and being straightened online .

[0005]

The roll straightening method according to the present invention is characterized in that a groove is formed by gouging on the convex side of the roll in which the bending is generated, and the groove is subjected to build-up welding for surface finishing. And

[0006]

The operation of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of the method of the present invention. Figure 1
As shown in FIG. 1A, the groove 2 is formed by gouging on the convex side of the roll 1 which is bent due to the effect of thermal stress. When overlay welding is performed on this groove 2,
The contraction force acts on the weld and the bend is corrected, and
Return to the original as shown in (c). It can be restored as is apparent from the center line A shown by the one-dot chain line in (a) and (c).

[0007]

【Example】

(Example 1) By the method as shown in FIG. 1, the bending of a roll having a diameter of 370 mm used in a continuous casting machine was straightened.
FIG. 2 is a sectional view of a roll having grooves formed by gouging. Reference numeral 2 is a groove formed by gouging.

FIG. 3 is a diagram showing the relationship between the build-up welding amount and the straightening amount of a roll having the same dimensions and the same material as those of this embodiment.
This relational expression is represented by the expression (1).

Y (bending correction amount mm) = 0.065X (welding amount kg) (1) Since the roll bending of this embodiment is 1.2 mm, 18.5 kg
Welding welding was performed. After that, the surface of the built-up portion was finished, and as a result, the operation could be continued without changing the rolls.

(Example 2) The bending of a roll having a diameter of 400 mm used in a continuous casting machine was straightened by the method shown in FIG. FIG. 4 is a relationship diagram between the amount of build-up welding and the amount of straightening of a roll having the same size and the same material as those of the present embodiment. This relational expression is represented by the expression (2).

Y (bend correction amount mm) = 0.063X (welding amount kg) (2) Since the roll bend of this embodiment is 0.8 mm, 12.7 kg
Welding welding was performed. After that, the surface of the built-up portion was finished, and as a result, the operation could be continued without changing the rolls.

[0012]

As described above, the roll bending can be corrected in a short time without changing the roll as described above.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method of the present invention.

FIG. 2 is a cross-sectional view of a roll grooved by gouging.

FIG. 3 is a relationship diagram between a roll straightening amount and a build-up welding amount in Example 1.

FIG. 4 is a relationship diagram between a roll straightening amount and a build-up welding amount in Example 2;

[Explanation of symbols]

 1 roll 2 groove

Claims (1)

[Claims] 1. A roll curl straightening method, characterized in that a groove is formed by gouging on the convex side of a roll in which a curl has occurred, and the groove is subjected to build-up welding for surface finishing.