JP2006199985A - Device for manufacturing hot-dip galvannealed steel sheet having oxide layer on plating surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for manufacturing a hot-dip galvannealed steel sheet having an oxide layer on a plating surface, and a device for manufacturing a galvannealed steel sheet having oxide layers of different film thicknesses on face and back plating surfaces. <P>SOLUTION: The device for manufacturing the hot-dip galvannealed steel sheet comprises an acid solution contact device (1), a cleaning device (3) arranged with a space from the acid solution contact device (1), and a drying device (4). After bringing the acid solution into contact with the surface of the galvannealed steel sheet in the acid solution contact device (1), oxides are generated on the plating surface between the acid solution contact device (1) and the cleaning device (3) to form the oxide layer on the plating surface. One or two or more deflector rolls (5a, 5b) to deflect the steel sheet traveling passage are arranged between the acid solution contact device (1) and the cleaning device (3). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for producing an alloyed hot-dip galvanized steel sheet having an oxide layer on a plating surface.

  By forming the oxide layer on the plating surface, the characteristics of the alloyed hot-dip galvanized steel sheet, for example, the slidability during press forming are improved. For example, in Patent Document 1 and Patent Document 2, a flat portion is formed on the surface of the plating layer, and an oxide layer having a thickness of 10 nm or more is formed on the flat portion, thereby improving the slidability during press molding. An alloyed hot dip galvanized steel sheet is disclosed.

  A method for manufacturing such an alloyed hot-dip galvanized steel sheet and its manufacturing apparatus are disclosed in Patent Document 3, Patent Document 4, and the like.

  Patent Document 3 describes the production of an alloyed hot-dip galvanized steel sheet in which an oxide layer is formed on the plating surface by subjecting the steel sheet to hot-dip galvanization, alloying treatment by heat treatment, temper rolling, and then contacting with an acidic solution. In the step, after contact with the acidic solution, the oxide layer having a thickness of 10 nm or more is formed on the surface of the flat portion of the plating surface by holding for 1 to 30 seconds and then washing with water.

  In an example of Patent Document 4, as an apparatus for forming an oxide on a plated surface of a temper-rolled galvannealed steel sheet, as shown in FIG. 1, an acidic solution tank (acidic solution contact tank) 1, A water washing tank (water washing device) 3 and a dryer (drying device) 4 are connected horizontally, and the amount of liquid film is adjusted between the acidic solution tank 1 and the water washing tank 3 by a squeeze roll 2 on the outlet side of the acid washing solution tank 1. It is described that a concentration region (reaction process) 8 that can secure a time for the acid solution on the plated surface to be concentrated to produce a desired oxide is provided and disposed.

In the above-described prior art, as a method for controlling the oxide film thickness, adjustment of the concentration of the acidic solution (Patent Document 1), adjustment of the standing time after contact with the acidic solution (Patent Documents 2 to 4), and throttling after the contact with the acidic solution The liquid film amount adjustment by a roll (patent document 3) etc. are illustrated.
JP 2001-131772 A JP 2002-302753 A JP 2003-306781 A JP 2003-231959 A

  The aforementioned prior art has the following problems.

  The first problem is that, in a horizontally connected path, in order to ensure a sufficient standing time from acid solution contact to water washing necessary for forming an oxide film, the plate passing speed is slowed down. Or the facilities will be long.

  The second problem is that the oxide film thickness is controlled on both sides in the same manner, and the front and back surfaces cannot be controlled to different film thicknesses.

  The present invention solves the aforementioned problems. The first problem is an alloyed hot dip galvanizing having an oxide layer on the plating surface that can solve the problem of slowing the plate passing speed or lengthening the equipment when forming an oxide film with a required film thickness. It is to provide steel plate manufacturing equipment. A 2nd subject is providing the manufacturing apparatus of the galvannealed steel plate which has an oxide layer of a different film thickness by plating front and back.

  Means of the present invention for solving the above-mentioned problems are as follows.

  1st invention is equipped with the acidic solution contact apparatus, the washing | cleaning apparatus arrange | positioned at intervals with the said acidic solution contact apparatus, and the drying apparatus, and is acidic on the surface of the plated steel plate after an alloying process with the said acidic solution contact apparatus. An apparatus for producing an galvannealed steel sheet for forming an oxide layer on the plating surface by generating an oxide on the plating surface between the acidic solution contact device and the cleaning device after contacting the solution, One or two or more deflector rolls for turning the steel plate traveling path are disposed between the acidic solution contact device and the cleaning device. Alloyed hot dip galvanizing having an oxide layer on the plating surface. It is a manufacturing apparatus of a steel plate.

  A second invention is the alloyed hot-dip galvanized steel sheet having an oxide layer on the plating surface, wherein the deflector roll is provided with a water spray device for cleaning the roll surface in the first invention.

  A third invention is the alloyed molten zinc having an oxide layer on the plating surface, wherein the number of deflector rolls brought into contact with the steel plate surface is different from the number of deflector rolls brought into contact with the back surface of the steel plate in the first invention or the second invention It is a manufacturing apparatus of a plated steel plate.

  According to the present invention, a deflector roll for turning the steel plate traveling path is disposed between the acidic solution contact device and the cooling device, and a path line combining a horizontal path and a vertical path is formed, or a horizontal path as necessary. By arranging the slant path obliquely with respect to the vertical path, it is possible to shorten the interval between the acidic solution contact device and the cleaning device while ensuring the reaction time required for oxide formation, and thereby the plate passing speed. Can be prevented, or the equipment can be made compact. By providing a water spray device for cleaning the deflector roll, the problem of acidic solution adhesion to the deflector roll does not occur.

  While the steel plate is in contact with the deflector roll, the oxidation reaction on the steel plate surface is suppressed, so by changing the number of deflector rolls in contact with the steel plate surface and the steel plate back surface, the alloy having oxide layers with different thicknesses on the front and back surfaces A hot-dip galvanized steel sheet can be manufactured.

  In the apparatus of the present invention, one or two or more deflector rolls for turning the steel plate traveling path are arranged between the acidic solution contact device and the cleaning device pass line, and the pass line is a combination of the horizontal pass and the vertical pass. Or, if necessary, by arranging a skew path that is skewed with respect to the horizontal path and the vertical path, the reaction time (pass line length) required for oxide formation between the acidic solution contact device and the cleaning device. ), The interval between the acidic solution contact device and the cleaning device (horizontal interval) can be shortened, thereby preventing a decrease in the plate passing speed or making the equipment compact.

  The acidic solution contact device, the cleaning device, and the drying device may be either a vertical type or a horizontal type. The method of contacting the acidic solution with the plated steel sheet in the acidic solution contact device is not limited, and an immersion method, a jet method, a spray method, a roll coating method, or the like can be employed. The washing method and the drying method are not limited.

  While the steel plate is in contact with the deflector roll, the oxidation reaction on the surface of the steel plate is suppressed. When forming an oxide layer with the same film thickness on the front and back surfaces of the steel sheet, the number of deflector rolls in contact with the front and back surfaces of the steel sheet is the same. When forming oxide layers having different film thicknesses on the front and back surfaces of the plating, the number of deflector rolls in contact with the front and back surfaces of the steel sheet is changed. The number of deflector rolls disposed between the acidic solution contact device and the cleaning device may be one or more.

  Hereinafter, an embodiment of an apparatus for producing a galvannealed steel sheet according to the present invention will be described.

  FIG. 2 is a side view showing the equipment layout of the apparatus for producing an galvannealed steel sheet having an oxide layer on the plating surface according to the first embodiment of the present invention. In FIG. 2, 1 is an acidic solution tank (acidic solution contact device), 2 is a squeeze roll, 3 is a water washing tank (cleaning device), and 4 is a dryer (drying device). The acidic solution tank 1, the water washing tank 3, and the dryer 4 are horizontal types. Two deflector rolls 5a and 5b that are in contact with one surface of the steel plate 5 (the upper surface side when the acidic solution bath is passed through and the rear surface side of the product in this apparatus) between the acidic solution tank 1 and the washing tank 3. Are arranged, and water sprayers 7a and 7b are arranged on the deflector rolls 5a and 5b, respectively. Each of the water sprays 7a and 7b can spray cleaning water over the entire width of the deflector rolls 5a and 5b. After spraying on the roll surface, the cleaning water on the surface of the roll is removed with a blade (not shown), and the acidity to the steel plate surface Spraying is possible regardless of whether there is contact with the solution.

  When the equipment length between the acidic solution tank 1 and the washing tank 3 in the apparatus of FIG. 1 in which the horizontal path is between the acidic solution tank 1 and the washing tank 3 is L (see FIG. 1), in the apparatus of FIG. The equipment length (horizontal equipment length) between the tank 1 and the washing tank 3 is 0.4 L, which is a compact equipment.

An example of a method for forming an oxide layer on the plating surface using this apparatus will be described. The temper-rolled galvannealed steel sheet 6 is passed through the acidic solution tank 1 and brought into contact with an acidic solution, for example, a sulfuric acid acidic solution. The amount of the liquid film is reduced to a predetermined liquid film amount, for example, 3 g / m ² or less by the squeezing roll 2 on the outlet side of the acidic solution tank 1. The travel path of the steel plate 6 that passes through the squeeze roll 2 and is a horizontal path is changed to a vertical path by the first deflector roll 5a, and then the horizontal path reverses to the first travel path of the steel plate by the second deflector roll 5b. It is turned and introduced into the washing tank 3. While passing through the squeezing roll 2 and being introduced into the washing tank 3, an oxide layer containing Zn is formed on the plating surface. The pass line length during this period is set so that the sheet passing time of the steel sheet is 1 to 30 seconds. The acidic solution remaining on the plating surface is washed and removed in the water rinsing tank 3 and then dried with a dryer 4 to obtain an alloyed hot-dip galvanized steel sheet having an oxide layer of 10 nm or more on the plating surface. Since the acidic solution adhering to each deflector roll 5a, 5b is cleaned by the water spray devices 7a, 7b and removed from the system, there is no problem due to the acid solution adhering to the surface of each deflector roll 5a, 5b.

  FIG. 3 is a side view showing an equipment layout of an apparatus for producing an alloyed hot-dip galvanized steel sheet having an oxide layer on the plating surface according to the second embodiment of the present invention. This apparatus is an example in which the acidic solution tank 1 is a horizontal type, and the water washing tank 3 and the dryer 4 are vertical types. In this apparatus, the three deflector rolls 5a to 5c that change the traveling direction of the steel plate are arranged so as to come into contact with one surface of the steel plate, and water sprays 7a to 7c are installed on the deflector rolls 5a to 5c, respectively. Yes.

  In this apparatus, the steel plate traveling path after contact with the acidic solution is changed from the horizontal path to the vertical path by the deflector roll 5a, and then the vertical path is changed from the vertical path to the horizontal path reverse to the first steel sheet traveling path by the deflector roll 5b. Next, the deflector roll 5 c changes the direction from a horizontal path to a vertical path, and sequentially passes through the washing tank 3 and the dryer 4. By using the apparatus of FIG. 3, an oxide layer can be formed on the plating surface in the same manner as the apparatus of FIG.

  In contrast to the installation length L between the acidic solution tank 1 and the washing tank 3 in the apparatus of FIG. 1, the installation length (horizontal length) between the acidic solution tank 1 and the washing tank 3 in the apparatus of FIG. It is a compact facility manager.

  FIG. 4 is a side view showing an equipment layout of an apparatus for producing an alloyed hot-dip galvanized steel sheet having an oxide layer on the plating surface according to the third embodiment of the present invention. In this apparatus, the acidic solution tank 1, the water washing tank 3, and the dryer 4 are vertical examples. In this apparatus, the two deflector rolls 5a and 5b that change the direction of the steel plate traveling path are arranged so as to come into contact with one surface of the steel plate, and water sprays 7a and 7b are respectively installed on the deflector rolls 5a and 5b. Yes.

  In this apparatus, the travel path of the steel plate 6 led vertically upward from the acidic solution tank 1 is changed to a horizontal path by the deflector roll 5a, and then changed to a vertical path by the deflector roll 5b. The plates are sequentially passed through the dryer 4. By using the apparatus of FIG. 4, an oxide layer can be formed on the plating surface in the same manner as the apparatus of FIG.

  By making the vertical path longer as in the apparatus of FIG. 4, the facility length in the horizontal direction can be further shortened. In contrast to the equipment length L between the acidic solution tank 1 and the rinsing tank 3 that can be placed in the apparatus of FIG. 1, the equipment length (horizontal length) between the acidic solution tank 1 and the rinsing tank 3 in the apparatus of FIG. It is a 2L compact equipment length.

  FIG. 5: is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which has an oxide layer on the plating surface based on the 4th Embodiment of this invention. This apparatus is an example in which the acidic solution tank 1 is a vertical type, and the water washing tank 3 and the dryer 4 are horizontal types. In this apparatus, the deflector roll 5 that changes the direction of travel of the steel plate is disposed so as to come into contact with one surface of the steel plate, and a water spray 7 is installed on the deflector roll 5. In this apparatus, the traveling path of the steel plate 6 led out vertically from the acidic solution tank 1 is turned into a horizontal path by the deflector roll 5 and is sequentially passed through the washing tank 3 and the dryer 4. By using this apparatus, an oxide layer can be formed on the plating surface in the same manner as the apparatus of FIG.

  By making the vertical path longer in the apparatus of FIG. 5, it is possible to further reduce the installation length in the horizontal direction. In contrast to the equipment length L between the acidic solution tank 1 and the rinsing tank 3 that can be placed in the apparatus of FIG. 1, the equipment length (horizontal direction length) between the acidic solution tank 1 and the rinsing tank 3 in the apparatus of FIG. It is a 2L compact equipment length.

  FIG. 6: is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which has an oxide layer on the plating surface based on the 5th Embodiment of this invention. In this apparatus, the acidic solution tank 1, the water washing tank 3, and the dryer 4 are horizontal. One deflector roll 5 a, 5 b in contact with each surface of the steel plate 6 is disposed between the acidic solution tank 1 and the water washing tank 3. The deflector roll 5 a is disposed substantially below the washing tank 3, and the deflector roll 5 b is disposed substantially above the acidic solution contact tank 1. The travel path of the steel plate 6 led out from the acidic solution tank 3 is changed by the deflector roll 5a from the horizontal direction to the oblique direction upward from the horizontal direction, and then the travel path of the steel plate is again horizontal (original) by the deflector roll 5b. In the same direction as the travel path).

  Since this apparatus has the same number of deflector rolls in contact with the front and back surfaces of the steel sheet, oxide layers having the same film thickness are formed on the front and back surfaces. If the equipment length between the acidic solution tank 1 and the rinsing tank 3 in the apparatus of FIG. 1 in which the steel plate traveling path between the acidic solution tank 1 and the rinsing tank 3 is only a horizontal path is L, the acidic solution tank in the apparatus of FIG. The equipment length (horizontal equipment length) between 1 and the washing tub 3 is 0.8 L, and can be made compact with respect to the apparatus of FIG.

  The alloyed hot-dip galvanized steel sheet produced as described above is excellent in slidability at the time of press molding because an oxide layer having a thickness of 10 nm or more is formed on the flat surface of the plating surface. It can be used for applications that require excellent slidability during press molding.

  For applications where different sliding characteristics are required on the front and back surfaces of the steel sheet during press forming, an alloyed hot-dip galvanized steel sheet having oxide layers with different film thicknesses on the front and back surfaces can be suitably used.

  After temper rolling using an acidic solution of sulfuric acid having a pH of 2.0 and 50 ° C. as the acidic solution, and using the apparatuses of FIGS. 2 to 6 in which the number of deflector rolls brought into contact with the steel plate surface is different between the acidic solution tank and the washing tank. The alloyed hot-dip galvanized steel sheet was contacted with the above-mentioned sulfuric acid acidic solution, washed with water and dried to form an oxide layer containing Zn on the plated surface. The film thickness of the oxide layer on the flat surface of the plated surface of the galvannealed steel sheet obtained above was measured. The formation conditions of the oxide layer and the film thickness measurement results of the oxide layer are shown in Table 1. The film thickness was evaluated by the film thickness ratio between the front and back surfaces. Table 1 also shows the results of the conventional apparatus for comparison.

  In the comparative example (conventional device), the front and back oxide film thicknesses are the same. In Invention Example 4, Invention Example 4 in which the number of deflector rolls in contact with the steel plate surface and the back surface is the same, but the oxide film thickness on the front and back surfaces is the same, but the number of deflector rolls in contact with the steel plate surface and back surface is different. -3 and 5 have different oxide film thicknesses on the front and back sides. When the number of deflector rolls in contact with the steel plate surface and the back surface is different, assuming that the oxide film thickness on the surface not in contact with the deflector roll is 1, the back surface in contact with the deflector roll has a thin oxide film thickness with respect to the surface. The film thickness decreased as the number of deflector rolls in contact increased.

It is a side view which shows the principal equipment arrangement | positioning of the apparatus which forms an oxide layer on the plating surface of a prior art. It is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which concerns on the 1st Embodiment of this invention. It is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which concerns on the 2nd Embodiment of this invention. It is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which concerns on the 3rd Embodiment of this invention. It is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which concerns on the 4th Embodiment of this invention. It is a side view which shows the equipment arrangement | positioning of the manufacturing apparatus of the galvannealed steel plate which concerns on the 5th Embodiment of this invention.

Explanation of symbols

1 Acidic solution tank (acidic solution contact tank)
2 Squeezing roll 3 Washing tank (cleaning device)
4 Dryer (drying equipment)
5, 5a-5c Deflector roll 6 Steel plate 7, 7a-7c Water spray (water spray device)
8 Concentration region (reaction process)

Claims (3)

An acidic solution contact device, a cleaning device spaced apart from the acidic solution contact device, and a drying device are provided, and the acidic solution is brought into contact with the surface of the plated steel sheet after the alloying treatment by the acidic solution contact device. Thereafter, an apparatus for producing an galvannealed steel sheet that forms an oxide layer on the plating surface by generating an oxide on the plating surface between the acidic solution contact device and the cleaning device, the acidic solution contact device 1 or 2 or more deflector rolls that change the direction of travel of the steel sheet are disposed between the cleaning device and the cleaning device. An apparatus for producing an galvannealed steel plate having an oxide layer on a plating surface. The said deflector roll is equipped with the water spray apparatus which wash | cleans the roll surface, The manufacturing apparatus of the galvannealed steel plate which has an oxide layer on the plating surface of Claim 1 characterized by the above-mentioned. 3. The apparatus for producing an galvannealed steel sheet having an oxide layer on a plating surface according to claim 1, wherein the number of deflector rolls brought into contact with the steel sheet surface is different from the number of deflector rolls brought into contact with the back face of the steel sheet. .

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