JP2006315073A - Recutting method for maintaining performance of rolling roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recutting method of a rolling roll for maintaining the performance of rolling roll in a rolling mill for rolling a material to be rolled having a rectangular cross section and to more prolong the life of the rolling roll with which the material to be rolled can be rolled without causing defects such as bends even when the roll diameter is made smaller by recutting. <P>SOLUTION: In the rolling mill with which the material 2 to be rolled having the rectangular cross section is rolled by passing the material through between the tapered parts of a pair of the rolling rolls 1 which are formed into a spindle shape by forming the tapered parts 1b, 1c on the sides of both end parts of a straight-shaped part 1a, by this method, the gradient of the tapered parts 1b, 1c is set so as to become a sharp angle in accordance with the thinning of the rolling roll by repeating correction when cutting the outer peripheral surface of the rolling roll 1 in order to correct the deformation caused by wear. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling roll refurbishing method for maintaining rolling performance in a rolling mill for rolling a material to be rolled having a square cross section.

In general, rolling rolls are worn and deformed by use, causing the material to be rolled to bend in the longitudinal direction, deteriorating the shape and dimensional accuracy and causing trouble to the rolling equipment. The deformed rolling roll is repeatedly used by cutting and correcting the deformation by applying a cutting bit to the outer peripheral surface. (See Patent Documents 1 and 2 below).
Japanese Patent Publication No. 8-11322 Japanese Patent No. 3243903

  And each time the deformation is corrected in this way, the outer diameter of the rolling roll gradually becomes thinner, the pressure resistance is lost, and the deflection due to the rolling load increases, so that it is still rolled by correcting the deformation as described above. When a rolling failure such as bending of the material does not fall within a predetermined allowable range, the rolling roll is discarded.

On the other hand, the invention of the rolling mill according to Japanese Patent Application No. 2003-337812 filed earlier by the present applicant, as shown in the schematic diagram of FIG. 1, the pair of rolling rolls 1 are closer to both ends of the straight portion 1a. Each of the tapered portions 1b and 1c is formed into a spindle shape. By passing a material to be rolled (a rectangular material having a square cross section) 2 between the tapered portions 1b or between the tapered portions 1c, FIG. As shown in Fig. 5, the material 2 to be rolled is uniformly pressed while the rolling roll 1 is bent by a rolling load. In other words, the material to be rolled 2 can be rolled without defects such as bending by forming a gradient in the tapered portions 1b and 1c that can cancel the deflection.
In FIGS. 1 and 2, for the sake of explanation, the amount of bending of the rolling roll and the gradient of the tapered portion are described as being excessively larger than actual.

By the way, the spindle-shaped rolling roll 1 has a constant slope of the tapered portions 1b and 1c at the time of the refurbishment. That is, conventionally, the taper portion is cut with a cutting tool so that the gradient of the tapered portion becomes a constant value regardless of the thickness of the rolling roll. For this reason, when the outer diameter of the rolling roll is reduced and the bending is increased, the material to be rolled is also bent, and the shape and dimensional accuracy are rapidly deteriorated.
The present invention seeks to remedy such problems.

  Therefore, the invention for the maintenance and refurbishment method for rolling roll performance described in claim 1 is that the taper portions are formed near the both ends of the straight portion so that the taper portions of the pair of rolling rolls are formed between the tapered portions. In a rolling mill that rolls through a material to be rolled with a square cross section, when cutting the outer peripheral surface of the rolling roll to correct deformation due to wear, the taper portion has a steep slope as the rolling roll becomes thinner by repeated correction. It is characterized by setting to.

  Even if the roll diameter is reduced, the material to be rolled can be rolled with high dimensional accuracy without rolling defects such as bending. For this reason, it is possible to roll the rolled material while maintaining the expected shape and dimensional accuracy without rolling defects such as bending by cutting the rolling roll by the performance maintaining cutting method according to the present invention. . Further, the number of times that the life can be extended by the refurbishment is increased, the economy is increased, troubles such as rolling equipment accompanying the bending of the material to be rolled are reduced, and the quality of the product is improved.

  Next, examples of the present invention will be described. The rolling roll 1 according to the present invention is made of ductile cast iron and has an overall length of 1600 mm and an outer diameter of 640 mm. As shown in FIG. 1, by forming tapered portions 1b and 1c near the both ends of the straight portion 1a, respectively. The tapered portion 1b has a gradient of 1/8000, and the other tapered portion 1c has a gradient of 1/10400. In use, the rolling roll 1 is attached to a roll stand (not shown), and a pair is supported in parallel at appropriate intervals as shown. And after passing the to-be-rolled material (square material with a square cross section) 2 between the taper parts 1b, this to-be-rolled material 2 is passed between the taper parts 1c from the opposite side of the roll stand. Thereby, a load is applied to the material 2 to be rolled, and the material is rolled. Needless to say, the material to be rolled 2 is also passed between the straight portions 1a.

Since the rolling roll 1 is worn and deformed by use, the cutting roll is applied to the outer peripheral surface of the rolling roll to modify the deformation, and the rolling roll is repeatedly used. As shown in Table 1, the gradient of the taper portion 1b and the taper portion 1c is set so as to gradually become steeper as the roll diameter becomes smaller. That is, in the rolling rolls shown in Table 1, when the roll diameter is changed to 620 to 600 mm when the taper portion 1b has an initial gradient of 1/8000, the gradient is reduced to 1/6000. When cutting the diameter to 600 to 580 mm, the gradient is set to 1/4000. In addition, when the roll diameter is changed to 620 to 600 mm, the taper portion 1c is initially set to 1/10400, the gradient is changed to 1/7800, and the roll diameter is changed to 600 to 580 mm. In this case, the gradient is set to 1/5200. As a result, the material to be rolled 2 can be rolled into a desired thickness and shape with a high dimensional accuracy of, for example, a tolerance of 0.5 mm or less without causing deformation such as bending even after cutting. In addition, when the roll diameter becomes 580 mm or less by repeating the cutting, and the required shape and dimensional accuracy cannot be obtained, the rolling roll 1 is discarded.

  As described above, in the present invention, by setting the slopes of the tapered portions 1b and 1c to be steeper as the roll diameter becomes smaller due to refurbishment, the roll diameter becomes thinner due to refurbishment and the amount of deflection gradually increases. However, since the tapered portion is formed to have a gradient that can offset the bending, the rolled material 2 does not cause rolling defects such as bending even if the roll diameter is reduced, and the desired shape and dimensional accuracy can be obtained. It can be maintained and rolled.

  In order to prevent rolling failure, the cooling capacity of the rolling mill is improved by the cooling water sprayed on the rolling roll, and the cooling water jetting control is improved so that the rolling roll is cooled uniformly. It is also important to do. Since the hardness of the roll surface is maintained by such uniform cooling, it is possible to prevent the rolling roll from being unevenly worn by use.

The schematic diagram of the rolling roll set to the rolling mill. The schematic diagram of the rolling roll of the state bent by the rolling load.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Roll 1a Straight part 1b Tapered part 1c Tapered part 2 Rolling material

Claims (1)

  By forming tapered portions near both ends of the straight portion, the deformation due to wear is corrected in a rolling mill that rolls a material having a rectangular cross section between the tapered portions of a pair of rolling rolls each formed in a spindle shape. Therefore, when cutting the outer peripheral surface of the rolling roll, the performance maintaining and refurbishing method of the rolling roll is characterized in that the gradient of the tapered portion is set to a steep angle as the rolling roll becomes thinner by repeated correction.

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