JPH05317910A - Manufacture of metal strip with high glossiness - Google Patents

Abstract

PURPOSE:To provide a manufacturing method by which a metal strip having excellent surface characteristic matched with the one rolled at low speed with a Sendzimir mill, particularly the metal strip of a stainless steel strip, etc., attaching importance to the glossiness can be rolled at high efficiency by using a high speed rolling mill having high productivity. CONSTITUTION:In at least a final pass in the case of cold-rolling by a reverse- mill or in at least a final stand in the case of cold-rolling by a tandem-mill, the rolls having roll axial directions of the grinding stripes and 0.20-0.60mum the average roughness (Ratheta) at a center line in the circumferential direction of the roll are used as the working rolls to execute the cold-rolling. Thereafter, the skin pass rolling is executed by using the rolls having <=0.02mum the average roughness (Ratheta) at the center line in the circumferential direction and also the average roughness (RaL) at the center line of the roll axial direction, respectively and using skin pass rolling solution as the work rolls. Thus, the surface of the metal strip after skin pass rolling is made to be smooth and high glossiness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention combines cold rolling using a roll with a special surface polishing state as a work roll and temper rolling using a roll with a large diameter as a work roll, and particularly, the glossiness is improved. The present invention relates to a method for producing an excellent metal plate with high efficiency.

[0002]

2. Description of the Related Art Cold rolling of a metal sheet such as a stainless steel sheet in which surface texture, particularly glossiness is important is usually carried out by a Sendzimir mill using a work roll having a small diameter of 100 mmφ or less. However, in recent years, rolling by a tandem mill or a revers mill of a rolling mill for ordinary steel using a work roll having a diameter of 180 mm or more has been performed. The reason is that in these mills, a roll having a large diameter is used as a work roll, and a water-soluble emulsion having a large cooling capacity is used as rolling oil, so that high-speed rolling is possible and high productivity can be expected.

However, the metal sheet rolled by a rolling mill for plain steel is inferior in glossiness to that obtained by rolling by a Sendzimir mill. This is because when high-speed rolling is performed with a work roll having a large diameter as described above, the amount of rolling oil introduced into the roll bite increases and an oil film forms between the work roll and the metal plate, freeing without being constrained. This is because the surface of the metal plate in the deformed portion is partially concaved by hydraulic pressure. So-called,
A minute defect called an oil pit occurs on the surface of the metal plate, which reduces the glossiness of the metal plate.

So far, proposals have been made to improve the glossiness of metal plates. For example, Japanese Patent Laid-Open No. 2-9240
No. 2 publication describes the average roughness (Ra) of the center line of the work roll.
A method of cold rolling has been proposed in which the rolling oil concentration is reduced to 0.2 μm or less and the rolling oil concentration is 2% or less. However, with this method, the oil film thickness is extremely thin, and insufficient lubrication occurs at the local convex portions on the roll surface, causing seizure due to oil film breakage, thus deteriorating the quality of the surface properties. Moreover, there is a problem that high speed rolling cannot be performed.

Japanese Patent Laid-Open No. 60-227904 discloses a method of cold rolling in which the direction of a grain on the surface of a metal plate and the direction of a grain on the surface of a work roll are crossed by belt grinding. Is disclosed. This method is based on the premise that the surface of the metal plate has a grind in the longitudinal direction.
By cutting the grinds on the surface of the metal plate with the grinds on the surface of the work roll, the oil pits are eliminated. Therefore, it is not possible to apply this method to a metal plate surface that has no longitudinal grinds, and it is inefficient to add such grinds beforehand because the number of processes increases and Investment is high.

Even if oil pits are formed on the surface of a metal plate in cold rolling, it is possible to increase the glossiness of the metal plate by rolling using a mirror finishing roll in temper rolling in the subsequent process. Seem. However, in temper rolling, the reduction ratio is generally as small as 2% or less, so it is extremely difficult to crush the oil pits generated in cold rolling by temper rolling, and the oil pits remain as they are, and the desired glossiness is obtained. Often not obtained.

Further, in the temper rolling, rolling without lubrication (hereinafter referred to as "dry rolling") improves the transfer efficiency of the roll surface of the mirror-finishing roll and enhances the glossiness of the metal plate. The method is also adopted. However, in this method, it is difficult to obtain a predetermined rolling reduction by one-pass rolling in order to obtain scratches due to the inclusion of abrasion powder or dust of the roll on the surface of the metal plate and the friction coefficient becomes high. Usually, there is a problem that the quality of the surface texture is deteriorated or the efficiency of the temper rolling operation is deteriorated, such as the necessity of rolling in two passes.

[0008] In the temper rolling described above, an attempt has been made to solve the problems in dry rolling by rolling using a temper rolling liquid (hereinafter referred to as "wet rolling"). However, the temper rolling liquid is filled in the oil pits generated during the cold rolling, and the temper rolling results in an increase of the oil pits, and the glossiness may be lower than that in the dry rolling. In addition, the lubrication action of the temper rolling liquid enclosed in the oil pit may cause a new problem that the friction coefficient is excessively lowered and it becomes difficult to perform temper rolling at a low pressure reduction rate of 2% or less.

As described above, various attempts have been made to increase the glossiness of the metal plate, but the current situation is that there is no method that can be industrially implemented and is effective.

[0010]

DISCLOSURE OF THE INVENTION The present invention is directed to a metal plate having an excellent surface property comparable to that of a product rolled at a low speed with a Sendzimir mill by using a high-speed rolling machine having high productivity, and in particular, stainless steel in which glossiness is important. The purpose was to develop a technology capable of rolling a metal plate such as a thin steel plate with high efficiency.

[0011]

Means for Solving the Problems In the course of research for enhancing the glossiness of a metal plate, the present inventor has conducted cold rolling using a roll having a special surface polishing state as a work roll and a work roll having a large diameter roll. It was found that it is possible to obtain a metal plate having an extremely excellent glossiness by combining it with temper rolling.

The gist of the present invention is the following rolling method.

In the production of a metal sheet which is cold-rolled, then annealed or annealed and pickled, and then temper-rolled, in the case of cold rolling with a levers mill, at least in the final pass, with a tandem mill. In the case of cold rolling, at least in the final stand, the polishing grain is in the roll axial direction, and the center line average roughness (Raθ) in the roll circumferential direction is 0.20 to 0.
Cold rolling was performed using a roll of 60 μm as a work roll, and then the centerline average roughness (Raθ) in the roll circumferential direction and the centerline average roughness (RaL) in the roll axial direction were 0.02 each.
A method for producing a metal sheet having high gloss, which comprises temper rolling using a temper rolling liquid with a roll having a diameter of 500 μm or less and a diameter of 500 mm or more as a work roll.

[0014]

The present invention was born from the idea that the problems in cold rolling and temper rolling described above could be solved all at once by adjusting the direction of the grain of the work roll and the surface roughness. It is a thing.

The surface of the metal plate before cold rolling is usually
The center line average roughness (hereinafter referred to as “Ra”) has a roughness of about 2 to 3 μm. Since the rolling oil trapped in the recesses of the surface roughness of the metal plate and the recesses of the surface roughness of the work roll exerts hydrostatic pressure during cold rolling, the work roll and the metal plate are separated by an oil film. Therefore, even if cold rolling is performed, not only the concave portion of the surface roughness of the metal plate does not disappear, but also the surface of the metal plate at a portion which is freely deformed without being restrained becomes partially concave due to the hydrostatic pressure of the rolling oil. This is a slight defect called the oil pit described above. A metal plate having a high glossiness cannot be obtained by temper rolling by various methods on a metal plate in which recesses of surface roughness remain or oil pits are generated in cold rolling.

In order to reduce the remaining surface roughness of recesses and the formation of oil pits, cold rolling is performed by setting a relatively large reduction rate and increasing the contact rate between the work roll and the metal plate. It is said to be good. However, although this method solves the problems associated with the concave portions of the surface roughness and the oil pits, it causes a problem that the polishing eyes themselves of the work roll are deeply transferred to the surface of the metal plate. Even when temper rolling is performed on the metal plate with the deeply polished work rolls still present by various methods, the glossiness of the metal plate is still not improved.

The cold rolling process in the method of the present invention will be described below.

FIG. 1 is a diagram for explaining the direction of the roll-polished grain, FIG. 1A is a diagram for explaining the inclination of the roll-polished grain, and FIG.
Is a diagram showing the direction of the roll polishing eye in the case of the conventional method,
(C) is a figure which shows the direction of the roll grinding | polishing in the case of the method of this invention.

As shown in (a), the angle between the roll-polished grain and the roll circumferential direction (direction perpendicular to the roll axis) is α.
In the conventional method, α is approximately 0 ° as shown in (b). That is, the roll polishing mesh is parallel to the roll circumferential direction.
On the other hand, in the method of the present invention, α is almost 90 as shown in (c).
Let be °. That is, the roll polishing meshes are parallel to the roll axis direction.

FIG. 2 is a diagram for explaining that there is slippage between the roll surface and the metal plate surface in cold rolling.
(A) is sectional drawing which shows a roll bite part, (b) is a figure explaining the locus | trajectory of a certain point on the roll surface on the metal plate surface.

When the metal sheet S is rolled by the work roll 1 from the thickness t ₁ to the thickness t ₂ in the X direction as shown in (a), the rolling speed v of the metal sheet S becomes the same as the roll peripheral speed V. The point is called the neutral point (N point), the area from the N point to the front (roll-out side) is called the advanced area, and the area from the N point to the rear (roll-in side) is called the reverse area. Further, if the rolling speed of the metal plate S on the roll entrance side (point A) is v ₁ and that on the roll exit side (point B) is v ₂ , then v ₁ <v ₂ .

Focusing on one point of the work roll 1 and rotating the point in the order of A point → N point → B point, the locus on the metal plate S is as shown in (b) point A → N point → B point. Thus, the rolling direction is opposite to the rolling direction X between point N and point B. The reason is,
Since there is a difference in the rolling speed of the metal plate between the advanced region and the reverse region, and the relationship between the roll peripheral speed V and the rolling speeds v ₁ and v ₂ of the metal plate S is v ₁ <V <v _2. Is.

FIG. 3 shows a transfer of a roll-polished grain formed on the surface of a metal plate when cold rolling is performed using a roll (conventional roll) whose grain direction is the circumferential direction of the roll (hereinafter referred to as ""Transferpattern"), (a)
Is a plan view for explaining rolling with a roll whose polishing grain direction is the roll circumferential direction, (b) is a diagram for explaining a locus on a metal plate at a point on the roll surface, and (c) is a transfer pattern of a metal. Sectional drawing explaining the width direction of a board, (d) is sectional drawing explaining the residual condition of an oil pit.

When the metal plate S is rolled in the X direction by the work roll 1 as shown in (a), the locus on the metal plate S at a certain point on the work roll 1 is point A as shown in (b). N
The point is changed to the point B, and the rolling direction X is opposite to the direction between the point N and the point B. If there is relative slip between the metal plate S and the work roll 1 as described above, the work roll 1 causes a slip flaw on the surface of the metal plate S.

When the transfer pattern in the case where the direction of the roll grind is the roll circumferential direction is seen in the widthwise cross section of the metal plate S,
As shown in (c), the unevenness of the roll-polished grain is emphasized and transferred. This is because, in addition to the transfer of roll polishing marks in the roll circumferential direction to the surface of the metal plate S, slip defects in the roll circumferential direction are formed, and both the roll polishing marks and the slip defects are emphasized by overlapping. is there. Further, when the cold rolling is performed using a roll whose polishing grain direction is the roll circumferential direction,
As shown in (d), an oil pit can be seen at a position corresponding to the valley of the surface roughness of the work roll 1. This is because oil pits are generated due to the oil film present in the valleys of the surface roughness, but even if slip flaws occur in the roll circumferential direction as described above when the direction of the roll grind is the roll circumferential direction. This is because the pit cannot be crushed.
That is, the generated oil pit remains as it is.

FIG. 4 shows an enlarged plan view of the surface of the metal plate and a sectional curve of roughness in the rolling direction after cold rolling is performed by a roll having a polishing grain direction in the roll circumferential direction (conventional roll). It is a figure. It can be clearly seen from the sectional curve in FIG. 4 that the oil pit remains as a recess.

Generally, temper rolling is the final step when producing a metal sheet having high gloss. Usually, it is dry-rolled using a mirror-finished roll to finally determine the gloss of the metal plate. Wet rolling may also be performed using a mirror-finished roll. However, as shown in FIG. 3 (d), wet rolling with a reduction rate of about 1%, which is called skin pass rolling, is performed on the surface of the metal plate in which the unevenness of the polishing roll of the cold rolling roll is emphasized and the oil pits remain. Even if (hereinafter, referred to as "wet skin pass rolling") is performed, a metal plate having a high gloss cannot be obtained. The reason is,
This is because even if a roll having a mirror finish is used, it is not possible to completely crush the oil pits and the concaves and convexes of the embossed polished mesh, and the surface of the metal plate cannot be made smooth. The oil pits and the convex portions of the embossed polished irregularities are smoothed to some extent, but the deep portions of the concave portions remain.

On the other hand, unlike the metal plate surface as shown in FIG. 3 (d), even if the extremely smoothed metal plate surface is subjected to wet skin pass rolling by using a mirror-finished roll, it is still glossy. A high-quality metal plate cannot be obtained. The reason is that oil tempering occurs on the contrary when temper rolling is performed. This is because even if both the roll surface and the metal plate surface are extremely smooth, if an oil film is formed between the roll surface and the metal plate surface due to the tempered rolling liquid that has been drawn in, the hydrostatic pressure of the oil film causes the metal plate surface to move. Is partially concave.

FIG. 5 is a diagram for explaining the transfer pattern formed when cold rolling is performed in the case of the method of the present invention, with the direction of the roll polishing grain being the roll axis direction.
Is a plan view for explaining rolling with a roll whose polishing grain direction is the roll axis direction, (b) is a diagram for explaining a locus on a metal plate of one polishing grain, and (c) is a metal plate by transfer 2D is a cross-sectional view in the plate width direction for explaining the degree of smoothing, and FIG. 7D is a cross-sectional view in the rolling direction for explaining the transfer of polishing eyes and the state of remaining oil pits.

When the metal plate S is rolled in the X direction by the work roll 1 as shown in (a), the locus of the metal plate S at one polishing eye in the roll axis direction is as shown in (b). A point → N point → B point, and the rolling direction X is the opposite direction between N point → B point. In this way, if there is relative slip between the metal plate S and the polishing eyes in the roll axial direction, the surface of the metal plate S is rolled in the circumferential direction by the roll polishing eyes having a certain length in the roll axial direction. Slip marks will occur.
That is, one polishing grain in the direction of the roll axis smoothes a partial area of the surface of the metal plate S.

When the transfer pattern is viewed in the cross section in the width direction of the metal plate S, the unevenness is gentle as shown in (c). Further, when the transfer pattern is viewed in a cross section in the rolling direction, only minute protrusions are present as shown in (d), and no oil pit is seen.

This is because the roll polishing marks are transferred to the surface of the metal plate S, and the oil pits are also temporarily generated by the hydrostatic pressure of the oil film existing in the valleys of the surface roughness, but the polishing marks in the roll axis direction are the metal plates. Since the surface of S is made smooth in the circumferential direction of the roll, the transferred polishing marks and the generated oil pits are crushed and almost disappear. In addition, as for the minute protrusions, the protrusion of the surface roughness of the roll is the metal plate S.
When the surface of the metal plate S was slid in the circumferential direction of the roll, the surface of the metal plate S was intruded into the concave portion of the surface roughness of the roll and further raised.

The fine projections are crushed during temper rolling in the subsequent process, but the deformation received at this time maintains a high friction coefficient in wet skin pass rolling to some extent, resulting in easy temper rolling. It becomes a thing. It also prevents excessive surface pressure from being applied to the surface of the metal plate during temper rolling, and thus prevents oil pits from occurring.

FIG. 6 is an enlarged plan view of the surface of the metal plate and a cross-sectional curve of roughness in the rolling direction after cold rolling is performed with a roll whose polishing grain direction is the roll axis direction. It is well understood from the sectional curve in FIG. 6 that minute protrusions are generated on the surface of the metal plate.

A metal plate having a transfer pattern obtained by cold rolling in the method of the present invention, that is, a metal plate having only minute projections but no oil pits, is used in the method of the present invention described later. If temper rolling is performed, a metal plate having high gloss can be obtained even if wet skin pass rolling using a mirror-finished roll is performed.

When the cold rolling method in the method of the present invention is applied, in the case of cold rolling by the revers mill, at least the final pass, and in the case of cold rolling by the tandem mill, at least the final stand, the direction of the polishing grain is If cold rolling is performed using rolls in the axial direction of the roll, seizure flaws (heat scratches) and slip flaws generated on the surface of the metal plate during rolling in the previous pass or stand can be crushed and smoothed. be able to.

In the work roll for cold rolling in the method of the present invention, the direction of the grind is the roll axial direction, and the center line average roughness (Raθ) in the roll circumferential direction is 0.20 to 0.60 μm.
Must.

When Raθ is less than 0.20 μm, the roll roughness is too small with respect to the oil film thickness, so that oil pits frequently occur. If the top of the surface roughness of the roll does not reach the valley of the generated oil pit, the original effect of crushing the generated oil pit cannot be seen.
If the top of the surface roughness of the roll does not reach the metal plate surface sufficiently, the metal plate surface is unlikely to rise due to the slip of the roll polishing, and a minute convex portion as shown in FIG. There is also a problem that it is not sufficiently formed. If the minute protrusions are not sufficiently present, the effect of increasing the coefficient of friction in wet skin pass rolling is reduced, the temper rolling is not stable, and oil pits are generated. Therefore, the lower limit of Raθ is set to 0.20 μm.

On the other hand, when Raθ exceeds 0.60 μm, even the valleys of the surface roughness of the roll are intruded into the metal plate surface during rolling, and the unevenness of the roll polishing is emphasized too much, and the depth of the transfer pattern in the cross-sectional direction is increased. Becomes excessively large. There is also a problem that new surface flaws such as local seizure flaws and indentation flaws due to abrasion powder of metal plates occur. Even if temper rolling is performed with the surface properties of the metal plate in such a state, it is difficult to smooth the convex portions on the surface of the metal plate, and a metal plate having a high gloss cannot be obtained. Therefore, the upper limit of Raθ is set to 0.60 μm.

The center line average roughness (Raθ) in the roll circumferential direction is
When cold rolling is performed using a work roll of 0.20 to 0.60 μm, desired minute convex portions are generated on the surface of the metal plate. It is desirable that the height of this minute convex portion is 0.5 to 2.0 μm.

Next, the temper rolling method in the method of the present invention will be described.

After performing the cold rolling in the above-mentioned method of the present invention, temper rolling is performed by using the rolls whose surface roughness and size are defined below, so that a metal plate having high glossiness can be obtained.

In the work roll for temper rolling in the method of the present invention, both the center line average roughness (Raθ) in the roll circumferential direction and the center line average roughness (RaL) in the roll axial direction are 0.02 μm or less. Must have a diameter of at least 500 mm.

The temper rolling is a rolling in which the rolling reduction is about 0.3 to 1.5%, slippage between the roll and the metal plate is reduced, and the metal plate is pressed by the roll. Therefore, the roughness of the roll surface is directly transferred, so Raθ and
If RaL exceeds 0.02 μm, the surface roughness of the metal plate will also be 0.02 μm.
This is because a metal plate having a high glossiness exceeding m cannot be obtained. Therefore, the upper limits of Raθ and RaL are 0.02 μm.

FIG. 7 is a view for explaining a situation in which the convex portion of the transfer pattern formed by cold rolling in the method of the present invention is crushed by temper rolling, and (a) is the roll diameter of temper rolling. Is small, (b) is a case where the roll diameter of temper rolling is large. If the roll diameter is less than 500 mm, the convex portions may be pushed obliquely as shown in (a), and may be crushed to be folded, or the folded convex portions may be torn off to become abrasion powder. If the metal plate after temper rolling has such a surface texture, its glossiness is difficult to improve. When the roll diameter is large, as shown in (b), the convex portion is crushed from above relatively, so that the convex portion is not crushed so as to be folded, and is not torn off to become abrasion powder. Therefore, the lower limit of the diameter of the work roll for temper rolling is set to 500 mm. If the roll diameter is 700 mm or more, the gloss of the metal sheet after wet rolling will be significantly improved.
That is all.

The manufacturing method of the present invention described in detail above will be summarized in FIG.

FIG. 8 is a diagram schematically showing the surface condition of each metal plate after cold rolling and during temper rolling by the wet skin pass rolling method and after temper rolling.

FIG. 8 (a) shows a case where cold rolling is carried out with a roll whose grain direction is the circumferential direction of the roll. After cold rolling, there are many recesses due to oil pits and slip flaws on the roll, and wet During skin pass rolling, the tops of the recesses are deformed due to high surface pressure, but the temper rolling liquid remains trapped in the valleys of the recesses, and the recesses remain after wet skin pass rolling.

FIG. 8 (b) shows, for example, when low-speed cold rolling is performed with a roll having a polishing grain whose direction is the circumferential direction of the roll but whose surface roughness is small, or when the direction of the polishing grain is the axial direction of the roll. It is a case where cold rolling is performed with a roll having a small surface roughness, and even if a smooth surface is obtained after cold rolling, there are few recesses during wet skin pass rolling, so there is a temper rolling liquid. As a result, the entire surface of the metal plate has a high surface pressure, and after wet skin pass rolling, oil pits are present in the soft part of the surface.

FIG. 8C shows the case where the cold rolling according to the present invention is performed, that is, the direction of the grain is the roll axis direction and the center line average roughness (Raθ) in the roll circumferential direction is 0.20 to 0.60.
This is the case when cold rolling is performed with a roll that is μm, and although there are minute protrusions after cold rolling, during wet skin pass rolling, the minute protrusions become deformed due to high surface pressure, After wet skin pass rolling, a smooth surface without oil pits is obtained. The temper rolling liquid may be a commercially available one which is usually used.

Next, the present invention will be described more specifically with reference to examples.

[0052]

[Example] First, in a 2Hi rolling mill equipped with 380 mmφ × 400 mmL rolls, SUS430 steel, thickness 3.2 mm, width 100 mm
The hot-rolled-annealed material of (1) was used as a test material, and the cold rolling rolls with the surface roughness and the polishing grain direction shown in Table 1 (the names of the rolls were A, B, C, D, E and F),
Cold rolling was performed up to 5 passes according to the rolling schedule shown in Table 2. The roll designation used in each rolling pass for each test No. is as shown in Table 4 below. As a lubricating oil for cold rolling, synthetic ester rolling oil (viscosity 25 cS
An emulsion having a concentration of 3% (t at 50 ° C.) was used.

Next, after annealing at 830 ° C. for 30 seconds in the atmosphere, electrolytic polishing was performed for 1 minute in a 15% nitric acid solution at 50 ° C. to remove the scale on the surface.

After that, rolls for temper rolling having the surface roughness and roll diameter shown in Table 3 (the names of the rolls are:
, And) were subjected to temper rolling. In the case of wet rolling, a 10% aqueous solution of a rolling oil containing alkylamine as a main composition was used as a temper rolling oil. In the case of dry rolling, there is no lubrication. The reduction rate in temper rolling is 0.8%,
The rolling was repeated until the predetermined rolling reduction was obtained.

Finally, the gloss of the rolled plate after temper rolling is
When measured with a reflection type gloss meter with an incident angle and a reflection angle of 45 °, and the measured value is less than 700 (“X” mark shown in Table 4 below), the measured value is 700 to 800 (same). "△"
(Marked) and the measured value exceeds 800 (marked “○” in the same figure). Further, as other surface quality qualities, the presence or absence of uneven gloss, the presence or absence of oil pits, and the presence or absence of indentation of abrasion powder were visually confirmed.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

Table 4 shows the names of rolls used in each rolling pass in cold rolling and the heights of the convex portions after rolling, the names of rolls used in temper rolling, the presence / absence of lubrication, and a predetermined rolling reduction. The number of passes is the surface quality after temper rolling: glossiness, presence of uneven gloss, presence or absence of oil pits, presence or absence of indentation of abrasion powder, and the total number of passes of temper rolling and surface quality. It describes the evaluation.

The presence / absence of gloss unevenness, the presence / absence of oil pits, and the presence / absence of indentation of wear debris are marked with an "X" mark when they are present, and a "○" mark when they are absent, and in the middle of them It is marked with "△". In addition, the category for comprehensive evaluation is that when one-pass temper rolling yields a rolled plate with high gloss, and with excellent surface quality without uneven gloss, indentation of oil pits and abrasion powder, ⊚ ”indicates that a rolled plate with high glossiness was obtained by one pass temper rolling, but if there were some uneven glossiness, oil pits or indentation of abrasion powder, it was marked with ∘.
When the pass was temper-rolled and the glossiness was low, or when the glossiness was high but the required number of passes in the temper-rolling was two or more, the mark was marked with "x". Further, those described in the column of the present invention examples are those obtained by performing cold rolling and temper rolling based on the method of the present invention, and those described in the column of comparative examples are:
Some or all of them are performed under conditions other than the method of the present invention.

[0061]

[Table 4]

Test Nos. 1 to 6 are examples of the present invention. That is, at least in the final pass, it has a polishing grain in the roll axis direction,
Cold rolling is performed by using rolls with Raθ of 0.20 to 0.60 μm as work rolls, and then temper rolling of wet rolling using rolls with Raθ and RaL of 0.02 μm or less and a diameter of 500 mm or more as work rolls. That is the case. In Test Nos. 2 to 5 of the present invention example, the rolled sheet having high glossiness and other excellent surface quality was obtained by temper rolling in one pass. In Test No. 1, although there was some oil pit, Test N
In o.6, although some abrasion powder was pushed in,
A one-pass temper rolling yielded a rolled plate with high gloss.

Test Nos. 7 to 12 are comparative examples. That is, when cold rolling is performed using a roll having a polishing grain in the roll circumferential direction in the final pass as a work roll (Test Nos. 7 and 12), Raθ is 0.20 although it has a polishing grain in the roll axial direction in the final pass.
When cold rolling is performed with work rolls of less than μm or over 0.60 μm (Test Nos. 8 and 9), and temper rolling is performed with the roll diameter of the work rolls being less than 500 mm (Test No. 10). And the case where the temper rolling of the dry rolling is performed (Test Nos. 11 and 12). In Test Nos. 7-10,
Although a predetermined rolling reduction was obtained by temper rolling in one pass, only a rolled plate having a low glossiness and having uneven glossiness, oil pits, or indentation of abrasion powder was obtained. In Test Nos. 11 to 12, although the gloss was high, indentation of abrasion powder was present on the rolled plate, and since it was dry rolling, three passes were required to perform temper rolling to a predetermined rolling reduction.

It can be seen that if cold rolling and temper rolling in the method of the present invention are carried out, a rolled plate having a high gloss can be obtained only by carrying out wet rolling in one pass.

[0065]

According to the method of the present invention, temper rolling using the temper rolling liquid can be performed after cold rolling.
With pass temper rolling, it is possible to obtain a metal plate that has an extremely high glossiness and is free from uneven gloss, oil pits, or indentation of abrasion powder. Moreover, since wet rolling using a work roll having a large diameter is performed, high-speed rolling is possible, and in particular, a stainless steel sheet having a high degree of importance on glossiness can be produced with high efficiency.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a direction of roll-polished eyes.

FIG. 2 is a diagram illustrating that there is slippage between a roll surface and a metal plate surface in cold rolling.

FIG. 3 is a diagram illustrating a transfer pattern formed on the surface of a metal plate when cold rolling is performed using a roll whose polishing grain direction is the roll circumferential direction.

FIG. 4 is an enlarged plan view of the surface of the metal plate and a cross-sectional curve of roughness in the rolling direction after cold rolling is performed with a roll whose polishing grain direction is the roll circumferential direction.

FIG. 5 is a diagram illustrating a transfer pattern formed on the surface of a metal plate when cold rolling is performed using a roll whose polishing grain direction is the roll axis direction.

FIG. 6 is an enlarged plan view of the surface of the metal plate and a cross-sectional curve of roughness in the rolling direction after performing cold rolling with a roll whose polishing grain direction is the roll axis direction.

FIG. 7 is a conceptual diagram illustrating a situation in which a convex portion of a transfer pattern formed by performing cold rolling in the method of the present invention is crushed by temper rolling.

FIG. 8 is a diagram schematically showing the surface condition of each metal plate after cold rolling, during temper rolling and after temper rolling.

Claims (1)

[Claims] 1. A tandem mill for at least a final pass in the case of cold rolling with a levers mill in the production of a metal sheet in which cold rolling is carried out, followed by annealing or annealing and pickling, followed by temper rolling. In the case of cold rolling in, at least in the final stand, the polishing grain is in the roll axial direction, and the center line average roughness (Raθ) in the roll circumferential direction is 0.20 to 0.
Cold rolling was performed using a roll of 60 μm as a work roll, and then the centerline average roughness (Raθ) in the roll circumferential direction and the centerline average roughness (RaL) in the roll axial direction were 0.02 each.
A method for producing a metal sheet having high gloss, which comprises temper rolling using a temper rolling liquid with a roll having a diameter of 500 μm or less and a diameter of 500 mm or more as a work roll.