JPH11129009A - Method of roll polishing and roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a thin steel sheet with good surface quality using the large diameter roll in high-speed and high-efficiency. SOLUTION: A roll profile is formed by conducting a circumferential direction polishing on the surface of the roll 3, and circumferential direction polishing grain 4 is given at circumferential direction average roughness of within Ra1=0.2-0.5 μm and afterwards an axial polishing grain 5 is given at axial average roughness within Ra2=Ra1×20-100% by axial polishing. On this occasion, if Ra1 is 0.2 μm or less the roughness of the roll is small and as a friction coefficient between the roll and the sheet lowers, a slip easily arises in the rolling. On the other hand, if Ra1 exceeds 0.5 μm, the slip flaws of the product after rolling by the polishing grain in the circumferential direction becomes noticeable. And if Ra2 is Ra1×20% or less, discharge effect of the filling oil is not sufficiently obtained, and on the other hand, if Ra2 exceeds Ra1×100% the circumferential direction polishing grain 4 does not remain on the surface of the roll 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll polishing method and a roll obtained by the polishing method.

[0002]

2. Description of the Related Art Rolling of a thin steel sheet having a severe surface quality, such as a stainless steel sheet, is performed by a 150 m diameter machine such as a Sendzimir mill.
The work rolls with a small diameter of less than m are used, but this is because when a roll with a large diameter work roll is used, oil enclosed in a roll bite causes a concave surface defect called an oil pit on a thin steel plate. .

However, rolling using a work roll having a small diameter of 150 mm or less has a problem that it is relatively difficult to perform high-speed and high-efficiency rolling compared to rolling using a work roll having a large diameter.

[0004] In view of the above, an oil pit is prevented by imparting a circumferential abrasive to the work roll to allow oil in the roll tool to escape from the abrasive during rolling.
As shown in Japanese Patent Application Laid-Open No. 5-96309, a work roll is provided with an axial polishing grain parallel to the rotation axis, and a small slip between the roll and the thin steel plate during rolling causes the work roll to have a convex portion. In order to improve the surface gloss of the thin steel sheet by crushing the convex portion of the thin steel sheet, thereby preventing the deterioration of the surface properties of the thin steel sheet, which is a problem when rolling is performed using a large-diameter work roll. What has been proposed.

[0005] Incidentally, as a method for giving the above-mentioned axial polishing marks to the roll, for example, as shown in Japanese Patent Application Laid-Open No. 7-265912, the rotation axis of the disc-shaped grindstone is offset from the roll axis, and in this state, 2. Description of the Related Art There is known an apparatus in which a whetstone and a roll are rotated and the whetstone is moved along the axial direction of the roll.

[0006]

SUMMARY OF THE INVENTION However, work
In the case where the roll is provided with circumferential polishing lines,
At the time of rolling, after the N point (neutral point)
Speed v of thin steel sheet₁Becomes smaller than the roll peripheral speed V,
Speed v of the thin steel sheet in front of point N (roll exit side) _TwoBut
Steel peripheral speed V, the thin steel sheet slips
The steel plate surface has slip flaws due to circumferential grinding.
In addition, there is an inconvenience of lowering the surface properties.

Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 5-96309, oil is less likely to be discharged in the roll bite than in the case of using a work roll having circumferentially polished edges, so that the oil on the rolling-in side is reduced. Oil is more likely to be filled in a concave defect such as an oil pit, which has a disadvantage that not only the ability to repair the concave defect is small, but also a new oil pit is easily generated.

Further, in the grinding method disclosed in Japanese Patent Application Laid-Open No. 7-265912, it is necessary to perform heavy polishing so as to change the roll profile, and there is a disadvantage that it is difficult to form a uniform axial polishing line. .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned inconvenience, and a roll polishing method and a roll capable of producing a thin steel sheet having good surface properties at high speed and high efficiency by using a large-diameter roll. The purpose is to provide.

[0010]

According to a first aspect of the present invention, there is provided a method for polishing a roll, comprising: performing a circumferential polishing to form a roll profile; and a circumferential average roughness Ra1 = 0. It is characterized in that circumferential polishing lines in the range of 2 to 0.5 μm are provided, and thereafter, axial polishing is performed to provide axial polishing lines in the range of average axial roughness Ra2 = Ra1 × 20 to 100%. And

According to a second aspect of the present invention, there is provided the roll, wherein the circumferential average roughness Ra1 is in a range of 0.2 to 0.5 μm;
An axial direction roughness Ra2 = Ra1 × 20 to 100% in the axial direction, wherein the axial direction polishing line is a polishing line formed after the formation of the circumferential direction polishing line. .

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view for explaining a method of giving circumferential polishing lines to a work roll for cold rolling, and FIG. 2 is giving an axial polishing line to the work roll for cold rolling after applying circumferential polishing lines. FIG. 3 is an explanatory view for explaining the method, FIG. 3 is an explanatory view for explaining the principle of improving the surface properties of the thin steel sheet by the axial polishing, and FIG. 4 is provided with both the circumferential polishing and the axial polishing. FIG. 5 is an explanatory diagram for explaining a roll for cold rolling, FIG. 5 is a schematic diagram showing a state inside a roll bite, and FIG. 6 is a graph showing a relationship between glossiness of a thin steel sheet and roll polishing.

First, as shown in FIG. 1, a rotating shaft 2 of a disc-shaped grinding wheel 1 is arranged in parallel with an axis of a work roll 3 for cold rolling (hereinafter simply referred to as a roll). The grindstone 1 is moved along the axial direction of the roll 3 while rotating the grindstone 1 and the roll 3 to perform circumferential polishing, thereby forming a roll profile and, at the same time, the axis of the roll 3 on the surface of the roll 3. Is provided with a circumferential polishing line 4 orthogonal to. Here, the circumferential average roughness Ra1 of the circumferential polishing line 4 is in the range of 0.2 to 0.5 μm. Ra1
If it is less than 0.2 μm, the roughness of the roll is small, and the friction coefficient between the roll and the plate is reduced, so that slip tends to occur during rolling. Slip flaws due to polished eyes in the direction become remarkable.

Next, as shown in FIG. 2, the rotating shaft 6 of the disc-shaped grindstone 5 is arranged orthogonal to the axis of the roll 3 and the rotating shaft 6 of the grindstone 5 is offset from the roll axis. In this state, the grindstone 5 is moved in the axial direction of the roll 3 while rotating the grindstone 5 and the roll 3 to perform the axial polishing parallel to the roll axis. 7 is given. Here, the average roughness Ra2 in the axial direction of the axially polished stitch 7 is in the range of Ra1 × 20 to 100%. If Ra2 is less than Ra1 × 20%, the effect of discharging the sealed oil cannot be sufficiently obtained, while if Ra2 exceeds Ra1 × 100%, the circumferential polishing streaks 4 will not remain on the surface of the roll 3.

As described above, in this embodiment, the roll 3
20-1 of circumferential polishing after giving circumferential polishing stitch 4 to
Since the axial polishing line 7 is provided by light polishing of 00%, irregularities of 0.04 to 0.5 μm in Ra2 exist in the axial direction, and the concave portion of the circumferential polishing line 4 is formed in the circumferential direction. A remaining roll surface is created.

Then, as shown in FIG. 4, when the stainless steel sheet 8 is rolled by using the roll 3 provided with both the circumferential polishing line 4 and the axial polishing line 7 by the above-mentioned roll polishing method, With reference to FIGS. 3 and 5, the convex portion of the stainless steel sheet 8 is caused by minute slippage of the axial polished stitch (convex portion) 7 caused by the difference between the roll peripheral speed on the rolling in / out side and the speed of the stainless steel sheet 8. Can be crushed to improve the surface properties (glossiness) of the thin steel plate 8, and the oil is discharged through the circumferential grinding line 4 in the roll bite.
It is possible to prevent a decrease in the ability of repairing a concave defect due to enclosing oil into a concave defect such as an oil pit on the rolling entry side, thereby preventing the generation of a new oil pit.

Further, in producing a special roll surface,
Roll profile and circumferential polishing 4 in circumferential polishing
Is formed and then lightly polished in the axial direction to form the axially polished stitches 7, so that a uniform axially polished stitch 7 can be easily formed and the axially polished stitches 7 can be formed. Can be more preferably made to appear on the roll surface as compared with a case in which the surface abrasive grains 4 are formed before the circumferential abrasive grains 4 are formed. Can be planned.

In the above-described embodiment, the case where both the circumferential polishing stitch 4 and the axial polishing stitch 7 are applied by the grindstones 1 and 5 is taken as an example. However, other than the grindstone, for example, lapping polishing or etching is applied to the roll surface. The circumferential polishing line 4 and the axial polishing line 7 may be provided.

Further, in the above-described embodiment, the case where the circumferential polishing line 4 perpendicular to the axis of the roll 3 is provided is taken as an example. However, the present invention is not limited to this, and is inclined with respect to the axis of the roll 3. A circumferential polishing line may be provided.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A roll 3 provided with a circumferential polishing line 4 and an axial polishing line 7 by the roll polishing method of the above embodiment is an example of the present invention, and a roll provided with only the axial polishing line 7 is a conventional example. In Example 1, the roll 3 provided with only the circumferential polishing line 4 was referred to as Conventional Example 2. Using the rolls of the present invention, Conventional Example 1 and Conventional Example 2, the stainless steel sheet was rolled under the same conditions except that the form of polishing was different. FIG. 6 shows the results. As is clear from the figure, it can be seen that in the rolling using the roll 3 of the example of the present invention, the glossiness is greatly improved as compared with the conventional examples 1 and 2.

[0021]

As is clear from the above description, according to the present invention, it is possible to improve the surface properties of a thin steel sheet by micro-sliding in the axial direction during rolling, and to improve the peripheral properties in a roll bite. The oil discharge function by directional polishing prevents oil from filling in concave defects such as oil pits on the rolling entry side, thereby preventing a decrease in the ability to repair the concave defects and preventing the generation of new oil pits. The advantage is that a thin steel plate having a good quality can be manufactured at high speed and high efficiency using a large-diameter roll.

Further, in preparing a special roll surface,
Since a roll profile and a circumferential polishing line are formed by circumferential polishing, and then light axial polishing is performed to form an axial polishing line, a uniform axial polishing line is easily formed. It is possible to improve the surface properties of the thin steel sheet, because the axial polished stitches can be better exposed on the roll surface as compared with the case where the axial polished stitches are formed before forming the circumferential polished stitches. Is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining a method of giving circumferential polishing lines to a work roll for cold rolling.

FIG. 2 is an explanatory diagram for explaining a method of giving an axial polishing grain to a work roll for cold rolling after the circumferential polishing grain is provided.

FIG. 3 is an explanatory diagram for explaining the principle of improving the surface properties of a thin steel sheet by an axially polished stitch.

FIG. 4 is an explanatory diagram for explaining a cold rolling roll provided with circumferential polishing lines and axial polishing lines.

FIG. 5 is a schematic diagram showing a state in a roll bite.

FIG. 6 is a graph showing a relationship between glossiness of a thin steel sheet and roll polishing line.

[Explanation of Signs] 3 ... Work roll for cold rolling 4 ... Circumferential polished line 7 ... Axial polished line 8 ... Stainless steel sheet

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI B24B 5/37 B24B 5/37

Claims (2)

[Claims] A roll profile is formed by performing circumferential polishing, and a circumferential average roughness Ra1 is 0.2 to 0.2.
A circumferential polishing grain in the range of 0.5 μm is provided, and thereafter, an axial polishing is performed to obtain an average axial roughness Ra2 = Ra1 × 20.
A roll polishing method characterized by providing an axial polishing grain in a range of 100% to 100%. 2. Average circumferential roughness Ra1 = 0.2 to 0.5
The circumferential polishing line in the range of μm and the axial average roughness Ra2 =
A roll provided with an axial polishing stitch in a range of Ra1 × 20 to 100%, wherein the axial polishing stitch is a polishing stitch formed after the formation of the circumferential polishing stitch.