JPH1080705A - Temper rolling roll of strip excellent in wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of a steel plate by coating a wear resistant metal on a working face of a recessed part of ruggedness formed on a roll surface through dull working so as to improve wear resistance and to prevent formation of indentation flaw due to sticking of foreign matter. SOLUTION: A ruggedness part having a recessed part 2 of 5-100μm depth, a flat area ratio of a projecting part 3 of 10-80% is formed on a roll surface 1 of the temper rolling roll. Formation of the ruggedness part is done by electrolytic etching or chemical etching, after forming of the ruggedness part, by coating with a wear resistant metal, fine ruggedness 4 generated on a working face (bottom part, side wall) of the recessed part 2, is flattened, also, wear of the projecting part 3 at rolling is protected through coating of the wear resistant metal 5 and durability of the roll 1 is improved. In this case, for the wear resistant metal, for example, electro-plated metal chromium, or electroless plated nickel-phosphor alloy is used and a coating thickness is set preferably to 3-95μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temper rolling roll for a plated steel strip having excellent wear resistance.

[0002]

2. Description of the Related Art As a roll of a steel strip, it is known to form irregularities on the roll surface to dull the rolled steel strip. As a method for forming irregularities on the roll surface, a method using laser, plasma, and electron beam is disclosed in Japanese Patent Application Laid-Open No. 63-10013.

[0003]

As described above, when a hot-dip galvanized iron-alloy-plated steel strip or the like is temper-rolled by a rolling roll, foreign matter such as zinc powder or iron powder adheres to the concave portion and pushes the steel strip. May occur. As a result of the present inventors' various studies on the mechanism of foreign matter adhesion to the concave portion, when the surface of the roll is formed asperities by laser, plasma, electron beam, or chemical etching, as shown in FIG. It was found that fine irregularities 4 were formed on the processing surfaces (bottom and side walls) of the three concave portions and the two concave portions. It has been clarified that such fine irregularities 4 capture foreign substances or gradually accumulate and grow on the three convex portions to generate press flaws in the steel strip during rolling. The present invention has been made on the basis of such knowledge, and abrasion resistance and the like are improved by coating abrasion-resistant metal on a processed surface of a concave portion of an uneven portion formed on a roll surface, and a foreign matter adhesion resistance is improved. It is an object of the present invention to provide a temper rolling roll of a plated steel strip excellent in quality.

[0004]

The feature of the present invention is that a concave and convex portion having a concave portion depth of 5 to 100 μm and a convex portion smooth area ratio of 10 to 80% is formed on the roll surface, and the concave portion has abrasion resistance. It is a temper rolling roll of a plated steel strip having excellent wear resistance characterized by being coated with a metal.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the irregularities formed on the surface of the rolling roll as described above, the concave portion has a depth of 5 to 100 μm, the convex portion has a smooth area ratio of 10 to 80% (substantially equidistant), and the shape of the convex portion has a smooth surface. Can have an appropriate shape such as a circle or a square. With such a roll, temper rolling is performed on a coated steel strip such as a hot-dip galvanized iron alloy-plated steel strip, a double-layer plated steel strip composed of a lower-layer hot-dip zinc-iron alloy plating, and an upper-layer electric zinc-iron alloy plating. This makes it possible to form irregularities on the plated steel sheet, which can prevent local peeling of the plating layer (die galling or the like) during press forming. Thus, the formation of the irregularities on the surface of the rolling roll can reliably form the irregularities as described above by, for example, chemical etching or electrolytic etching. However, when the irregularities are formed by the chemical etching, the concaved surface (bottom or side wall) can be formed. Since fine irregularities are formed on the surface of the roll, the surface of the roll is coated with a wear-resistant metal to flatten the fine irregularities on the concave processing surface (bottom and side walls) to prevent adhesion and accumulation of foreign substances and improve wear resistance. Is what you do. That is, as shown in FIG. 1, after forming three concave portions and two convex portions on the surface of the rolling roll 1, by coating as a wear-resistant metal 5, fine irregularities 4 on the processed surface of the concave two portions (bottom and side walls) are formed. In addition to being flat, the three convex portions are coated with the wear-resistant metal 5 which is a hard metal, so that the wear resistance of the three convex portions can be improved and the durability of the rolling roll 1 can be increased.

[0006] As described above, as a method of coating the wear-resistant metal on the surface of the rolling roll after forming the irregularities, for example, when the irregularities are formed by chemical etching, first, a resist agent is applied to the surface (entire surface) of the rolling roll. After coating and photo-curing the portion corresponding to the convex portion, the resist material in the unexposed portion (uncured portion) corresponding to the concave portion is washed and removed, and then the resist material is etched by contacting with an etching solution. The concave portion is formed by forming the concave portion.
Thereafter, the resist agent in the convex portions is removed, and the entire surface is coated with a wear-resistant metal by a plating method as described later.

[0007] As the wear-resistant metal as described above, for example, metal chromium, nickel-phosphorus alloy and the like can be coated. Metal chromium can be coated by electroplating, and nickel-phosphorus alloy can be coated by electroless plating. With a coating thickness of 3 to 95 μm, the recessed surface (bottom and side walls) can be reliably flattened, and such metal is hard and the wear resistance of the rolling roll is increased, and the recessed surface is improved. And the life of the smooth surface of the convex portion can be improved, and the durability can also be improved.

Next, as a method of forming an uneven portion on the surface of the rolling roll by electrolytic etching, for example, first, a resist agent is applied to the surface (entire surface) of the wear-resistant metal coated on the surface of the rolling roll, and a resist is applied. After the portions to be exposed are cured by light, the resist agent in the unexposed portions (uncured portions) corresponding to the concave portions is washed and removed, and then, as shown in FIG. The electrolytic etching liquid 8 of 7 flows down from the nozzle 10 to the rolling roll 1 via the pump 9, flows along the rolling roll 1, flows into the electrolytic etching liquid tank 7 from the electrolytic etching liquid receiving pan 11, and from the electrolytic etching liquid tank 7 While circulating again to the nozzle 10, it is brought into downward contact with the surface of the rolling roll 1, while simultaneously rotating the rolling roll 1, the electrode 12 is a cathode, and the rolling roll 1 is an anode. Te energized from a power source 13 to form the uneven portion by forming a concave portion of the resist material removal site by electrolytic etching.

As described above, while the electrolytic etching solution is caused to flow down to the surface of the rolling roll, in the electrolytic etching, the engraving processing speed by the etching of the surface of the rolling roll is increased by 10%.
By not exceeding μm / min, it is possible to prevent the formation of fine irregularities on the processed surface of the concave portion and to perform electrolytic processing for making the processed surface smooth. Also, if the engraving processing speed by etching is too small to improve the smoothness, the resist agent may expand and be easily peeled off. The lower limit of the engraving processing speed is 0.05 μm / min or more. Is preferred.

In the electrolytic etching as described above,
When a passivation film is formed at the electrolysis site of the rolling roll 1 during electrolysis, fine irregularities may be formed on the surface of the uneven portion or workability may be reduced. Sodium chloride aqueous solution (10-2
5%) or the like. In addition, electrolytic etching can be performed at a liquid temperature of normal temperature to 60 ° C. If the liquid temperature is higher than 60 ° C., heating by electrolysis may be applied to reach a boiling temperature, which is not preferable.

In order to reduce the processing speed to 10 μm / min or less while flowing down such an electrolytic etching solution to a rolling roll, for example, in the case of chromium plating, the current linear density to be applied is 3 to 15 A / min. In cm, the formation of fine irregularities on the bottom and side walls of the concave portion can be prevented, and the electrolytic processing can be performed flat. That is, if the current linear density is less than 3 A / cm, fine irregularities are formed on the bottom and side walls of the concave portion, which is not preferable.
If it exceeds A / cm, the resist agent applied as described above is peeled off, and the convex portions are also etched, so that a desired concave portion depth cannot be obtained, which is not preferable.

When the recess is processed by electrolytic etching as described above, the bottom and the side wall of the recess are formed with almost no minute unevenness and are flat, and it is possible to prevent a pressing flaw on the plated steel strip due to adhesion of foreign matter during rolling. However, as shown in FIG. 3, by coating the surface of the concave portion 2 and the surface of the convex portion 3 of the rolling roll 1 with the wear-resistant metal 5 by electrolytic etching, the wear resistance is improved and a large amount of rolling is stably performed. be able to.

In such a roll of the present invention,
Since the irregularities are deep and can be formed almost in the direction of the center of the roll, the shape of the irregularities does not change due to the abrasion caused by rolling, and the dull (irregularities) that does not generate mold galling etc. during press forming of the plated steel strip (plate) is plated. It can be formed on a steel strip and, as described above, can prevent foreign matter from adhering to prevent the occurrence of a press flaw on the plated steel strip. That is, the rolling roll of the present invention is a rolling roll that has excellent wear resistance and can be rolled into a plated steel strip having excellent press formability.

[0014]

Next, examples of the present invention will be described together with comparative examples.

[Table 1]

Note 1: The unevenness is formed in Examples 1, 3, and 5 and Comparative Examples 1, 2, and 3 by a generally used chemical etching method. In Examples 2, 4, and 6, an aqueous solution of sodium chloride (10 to 25%, a liquid temperature of room temperature to 60
° C) flows down from the upper part of the roll, and the electrode at the falling position is a cathode
Formed by electrolytic etching (etching engraving speed 0.2 to 10 μm / min) at a current linear density of 3 to 15 A / cm and a roll rotation peripheral speed of 10 to 40 mpm using the roll as an anode. Comparative Examples 4, 5, and 6 were formed by a laser. Note 2: Metal is a wear-resistant metal, electroplated with Cr (metal chromium), Ni-P alloy (P5%, Ni remaining)
Covered by electroless plating. Note 3: In Examples 1, 3, and 5 and Comparative Examples 1, 3, and 5, the molten zinc-iron (iron 10%, remaining zinc) alloy plating (adhesion amount 4
0g / m ² ) Rolled coated steel strip. In Examples 2, 4, and 6 and Comparative Examples 2, 4, and 6, the lower molten zinc-iron (iron 10%,
Rolled plated steel strip with zinc (alloy remaining) alloy plating (adhesion amount 30 g / m ² ) and upper layer electro-melted zinc-iron (iron 85%, zinc remaining) alloy plating (adhesion amount 5 g / m ² ). Note 4: Degradation rate of press flaw is 0.6mm in thickness and 900m in width.
The rate at which the product was downgraded due to the occurrence of press flaws due to foreign matter adhering to the rolling roll when the steel strip of m was rolled for 40,000 t was indicated. Note 5: The mold galling evaluation was performed by subjecting the plated steel strip after temper rolling to a square bead portion tensile test. The specimen size is 17
Anti-corrosive oil (Knoxlast 530 manufactured by Nippon Parker Rising Co., Ltd.)
Was applied at 1 g / m ² . The bead shape has a protrusion height H: 6 mm, width D: 6 mm, and a shoulder radius of 2R.
FIG. 4 shows the basic shape of the square bead. The test piece 14
A load test of several steps is performed in the range of a bead holding load of 100 to 300 kgf, and a continuous 30 times at a pulling speed of 500 mm / min.
After pulling in the longitudinal direction of 0 mm, a tape test was performed on both sides of the bead contact, and the flaking resistance was judged from the degree of blackening. In the evaluation leaf and the area where the holding load was high, those that did not cause plating peeling were evaluated as good, and those that easily peeled in the low load area were evaluated as inferior (◎ indicates practically no problem, ○ indicates practically no problem, Δ indicates use) (Be careful, X cannot be used.)

[0016]

According to the present invention, it is possible to reliably prevent foreign matters from adhering to the rolling rolls and to significantly reduce the pressing flaws of the plated steel strip, thereby improving the quality of the steel strip. Product yield can be increased. Also,
Excellent effects such as little change in the shape of the uneven portion due to abrasion of the rolling roll, and reduction of product deterioration due to mold galling and the like can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of a rolling roll of the present invention.

FIG. 2 is a front view showing an example of an apparatus for forming uneven portions on the surface of the rolling roll of the present invention.

FIG. 3 is a sectional side view of a main part of the rolling roll of the present invention.

FIG. 4 is an explanatory view of a method for tensile test of a square bead portion.

FIG. 5 is a sectional side view of a main part of a conventional rolling roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roll roll 2 Concave part 3 Convex part 4 Fine unevenness of concave part bottom 5 Wear-resistant metal

Claims (3)

[Claims] A concave portion having a depth of 5 to 100 μm on a roll surface;
A temper rolling roll for a plated steel strip having excellent wear resistance, characterized by forming a concavo-convex portion having a convex portion smooth area ratio of 10 to 80% and coating the concave portion with a wear-resistant metal. 2. A concave portion having a depth of 5 to 100 μm on a roll surface,
2. The plated steel strip having excellent wear resistance according to claim 1, wherein the projections and depressions having a smooth area ratio of 10 to 80% are formed by electrolytic etching, and the depressions are coated with a wear-resistant metal. Temper rolling roll. 3. A concave portion having a depth of 5 to 100 μm on a roll surface.
The unevenness | corrugation part of a convex part smooth area ratio of 10-80% was formed by chemical etching, and this recessed part was coated with a wear-resistant metal, The coated steel strip excellent in wear resistance of Claim 1 characterized by the above-mentioned. Temper rolling roll.