JPH0399715A - Roll for giving difference of tension to metallic strip - Google Patents

Abstract

PURPOSE:To improve wear resistance of roll and to prevent sticking of foreign matters such as iron powder by dulling the surface of bridle roll and the like on which hot-melt-spray-coating of a composite material or a ceramic is performed and buffing both end parts. CONSTITUTION:After hot-melt-spray-coating of the composite material or the ceramic is performed on the dulled surface of a roll with body length L, both end parts of the roll 1 including the parts where the edge parts of the metallic strip are brought into passing contact, i.e. the surface from each end of the roll to 3L/10 is buffed. Therefore, because the surface of the middle part of roll without buffing has peculiar ruggedness of hot-melt-spray-coating, force for gripping the metallic strip is sufficiently obtained. And, because both end parts where are buffed are almost reduced with small and sharp ruggedness, it is difficult for metallic powder itself to be stuck. Then, because scabs on the edge parts of strip aren't shaved off with this ruggedness, the generation of metallic powder itself is remarkably decreased.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a 11-
This is related to LE.

<Prior Art> In order to perform surface treatment or adjust the shape of a strip while stably passing it through -C, an optimum strip tension is required for each. For example, as a roll that generates this tension, there is a bridle roll 1 shown in FIG. 1 that is provided before and after a tension leveler. Because the load on this roll is so high, it wears out faster than other rolls and soon slips occur. FIG. 2 is a schematic diagram showing the state of wear. If the strip slips, the necessary strip tension cannot be achieved and a number of problems occur. Therefore, conventionally, as shown in Fig. 3, N shrine 2 was
1 Coal was used, which had a hardened surface of about 80 to 90 with a dull grain and Cr plating 3 applied. However, even this Cr-plated roll wears quickly and slips soon occur. For this reason, the rolls had to be replaced in a short period of time, causing a significant increase in repair costs.

The 4th layer is placed on the roll surface where the surface of the base material 2 has been dulled.
As shown in the figure, rolls coated with a thermal spray coating 4 of composite material or ceramics have recently come into use. However, the surface smoothness profile of this type of roll has many unevenness with a large pitch and sharp unevenness with a fine pitch, as shown in Figure 5, and it is thought that these fine and sharp unevenness are formed during rolling. In order to scrape away the flakes shown in FIG. 6 on the strip edge, the scraped flakes turn into powder and adhere to the surface of the ml-le near the strip edge due to the anchoring effect of the above-mentioned unevenness. do. As a result, the metal powder becomes protrusive on the roll surface, and the shape is transferred to the strip, causing surface defects.

Therefore, in order to prevent the occurrence of surface defects, JP-A-62-
In Japanese Patent No. 16808, as a surface-coated roll to prevent the adhesion of foreign substances such as metal chips, the roll surface is polished and dulled, and then a composite material with excellent wear resistance is coated.
We have proposed a metal strip cable with chromium plating on the surface of this composite material.

However, in the surface processing process of the 1"-ru, as shown in FIG. 7, a composite shrine O', 14
After coating with (tungsten carbide Kobal 1/shade), Cr plating 3 is applied, but when Cr plating 3 is not applied, it is necessary to immerse the roll in a plating solution. However, when looking at the cross section of the roll coated with the composite 4A material 41 as shown in FIG.
There are many holes 8 that reach the surface of the base material 2, and through these holes, the liquid reaches the surface of the base material 2 and corrodes the surface of the base material.

This corrosion causes peeling between the base material 2 and the composite material layer 4. Furthermore, since the composite material layer 4 has poor electrical conductivity, the strength of the Cr plating film decreases and it easily peels off. Due to the above two reasons, this technique was not practical.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned problems and provide a roll that has excellent wear resistance and prevents the adhesion of foreign substances such as iron powder.

<Means for Solving the Problems> The present invention provides a prydle, a pinch l'', etc. having a dull surface, on which a thermal spray coating of a composite material or ceramics is applied, and a metal A roll for applying a tension difference to a metal strip, characterized in that both ends including the part where the edge part of the strip comes into contact with the plate are buffed, and preferably the roll is further coated with a spray resin. be.

<Function> FIG. 9 shows a conceptual diagram of the processing method and surface condition of a roll according to an embodiment of the present invention.

Figure 9 (a) is a conceptual diagram in which the dulled surface of a roll body length of 0, ) is thermally sprayed with a composite material or ceramics, and then the surface from the left and right end faces of the roll to 3/IOL is buffed once. and the roughness profile in that case.

FIG. 9(b) shows a conceptual diagram when resin is further sprayed onto the entire surface of the roll of FIG. 9(a).

From this figure, the surface condition at the center of the roll, which was not buffed, has unevenness unique to thermal spraying, so it was possible to obtain enough force to grip the metal strip, and buffing was performed on the left and right end surfaces of the roll. This is because the fine and sharp irregularities have been almost completely reduced, making it difficult for the metal powder to adhere to the metal powder itself. It is thought that the unevenness will prevent the stubble from being scraped off at the strip edge, and the generation of metal powder itself will be drastically reduced.

Furthermore, by applying a resin coating to the roll of the present invention, not only the wear of the unevenness imparted to the roll is reduced, but also the metal powder is further removed, especially at the end of the roll.
This results in effects such as less adhesion, and further reduction in scraping of bald spots at the strip edges.

By the way, the part of the roll that the metal strip comes into contact with during passing is 1// from the end surface of the roll, where L is the length of the roll.
It usually exists in the range of I to 1/20L.

Therefore, in the present invention, it is desirable that the range to be buffed is selected from this range depending on the line situation.

Furthermore, the degree of roughness of the dull surface of the roll of the present invention is Ra
A range of 4.0-12.0 pm is desirable. Ila 4
．． 01jT! If it is less than 1, the grip force on the strip will be too weak, which is undesirable, and if it exceeds 12.071 m, the rounded peaks will cause flow restriction on the strip, which is very likely to result in quality deterioration, which is undesirable.

Further, the degree of buffing can be adjusted by changing the number of times of buffing. If the roughness of the dull processing is large, it is desirable to perform Hough polishing two or more times to smooth the surface. In addition, the area where the strip edge comes into contact with the end of the roll is buffed many times to improve smoothness.
From the center of the roll, the roughness can be increased by buffing about once, and the grip strength can be maintained.

As the composite material (cermet) used for coating the melt 1 of the present invention, tungsten carbide-cobalt type, chromium carbide-nira gel-chromium type, ditanium 11 carbide ninkel-chromium type, etc. can be used. Ceramics include chromium oxide, chikunia,
White alumina type, tungsten carbide type, chromium carbide type, etc. can be used.

In the present invention, it is desirable that the resin coating be thicker at the buffed edges than at the center.

In addition to silicone resins, Teflon resins, epoxy resins, and the like can be used as the spray resin coating resin used in the present invention.

Next, the present invention will be explained in more detail with reference to Examples.

<Example> Example 1 A composite material (W C-12Go) to JET-KOT
Sprayed using the E method. At this time, the surface roughness Ra was 8 to 9. Then, buffing finish (polishing conditions (1) Buffing material: Kenmaron (Scotch Bligh l-), #80φ350
×30 width (2) Construction conditions/Roll circumferential speed 209-262
mm/S, buff rotation speed 1.200 rpm, feed speed 5
mm/rcvl three times from the left and right end faces of the roll to 350 mm, and from that 350 mm to 525 mm.
I went there once in the meantime.

Example 2 The entire roll of Example 1 was spray-coated once with a silicone resin, and the buffed portion was further spray-coated twice.

When the rolls of the present invention of Examples 1 and 2 prepared as described above were used as bridle rolls in tension leveler lines of steel slips and lips, respectively,
In both the rolls of Examples 1 and 2, there was no metal powder τJ adhering to the surface near the strip edge J, and therefore, surface defects due to transfer of the adhered metal powder to the strip did not occur. Furthermore, the roll life was significantly extended to more than 12 months in Example 1 and more than 16 months in Example 2, compared to the life of conventional Cr-plated rolls (approximately 4 months).

Example 3 Bridle roll used before and after skin pass (body length 122
0 mm), the surface was subjected to dull processing (Ra 8.0 to 10.0 before skin pass; Ra 6.0 to 8.0 before skin pass) using an alumina grid material.

- Meth I- (CriCz) was sprayed using a plasma method (Ra 6.0 to 7.0 for before skin pass, Ra 4.0 to 5.0 for skin pass removal), then buffed and polished. Row (!l) (1) Buffing material: Kenmaron (Scotch Bligh I-), #80φ350 x 30 width, (2)
Construction conditions: Two roll circumferential speed 209-262mm/s,
Buff rotation speed 120Orpm, feed speed 5mm/rev)
This was performed three times for a distance up to 250 mm from the left and right end faces of the roll, and twice for a distance from 250 mm to 400 mm.

Example 4 The entire roll of Example 3 was spray-coated twice with epoxy resin, and the buffed fins were further spray-coated once.

When the rolls of the present invention of Examples 3 and 4, which were prepared as described above, were used before and after the skin pass of the steel strip, both the rolls of Examples 3 and 4 showed that the gold Fi on the surface near the strip edge (=J) i5) 41 deposits were completely eliminated, and therefore surface defects due to transfer of adhered metal powder to the stamping pump were no longer generated.

Moreover, the roll life is also the same as that of the conventional Cr plated roll (
In Example 3, it was 9 months or more before the skin pass and 6 months or more after the skin pass, and in Example 4, it was 12 months or more before the skin pass, and 8. It has been significantly extended to more than a month.

<Effects of the invention> As described above, by using the roll of the present invention,
This eliminates the generation of metal powder caused by scraping off the edge of the strip edge and the adhesion of metal powder to the roll surface, which prevents surface defects on the strip and greatly extends the life of the roll, reducing roll repair costs. did not result in a significant decrease in

[Brief Description of the Drawings] Figure 1 is a schematic diagram of a line to which the roll of the present invention is applied;
Fig. 2 is a schematic diagram showing the roll wear state, Fig. 3.4 is an explanatory diagram showing the conventional roll surface coating structure, and Fig. 5 is a schematic diagram showing the state of roll wear.
The roughness profile of a conventional roll, Fig. 6, is an explanation showing the fringing of the strip edge part.1 The gruel diagram, Fig. 7 is an explanatory drawing showing the conventional roll surface coating structure, and Fig. 8 is the conventional roll surface. FIG. 9(a), an explanatory diagram showing the cross-sectional structure of the coating, is a conceptual diagram of the roll of the present invention and the roughness profile after buffing. (1) is another example of the conceptual diagram of the roll of the present invention. 1... Bridle roll, 2... Base material surface, 4... Composite 1 layer or Cera 5... Slippery lip, 7... Paris, 3... Cr plating layer, mix layer (?8 QJ layer), 6...Slip edge, 8...hole. 1) Applicant Kawasaki Steel Corporation 2 Figure @ 3 Funeral diagram Funeral diagram

Claims (1)

[Scope of Claims] 1. A bridle roll, a pinch roll, etc., which has a dulled surface, is coated with a composite material or ceramic by thermal spraying, and includes a portion where the edge of the metal strip comes into contact with the plate when passing through it. A roll for creating a tension difference on sliding metal strips, characterized by having both ends buffed. 2. A roll for tensioning a metal strip according to claim 1, further comprising a spray resin coating.