JPS60197276A - Surface treatment of aluminum-zinc alloy plated steel plate - Google Patents

Abstract

PURPOSE:To form a uniform good film, by spraying wax solid at an ambient temp. to the surface of an aluminum-zinc alloy plated steel plate under an atmosphere set to a temp. equal to or more than the m.p. of wax in a molten state. CONSTITUTION:An aluminum-zinc alloy plated steel plate, of which the surface preliminarily received chromate treatment, is sent into a coating apparatus and molten wax is sprayed to both upper and lower surfaces of the steel plate from sprayers 5 during the passage through a chamber 8. At this time, sprayed wax is deposited to the surface of the steel plate with good efficiency by the action of high voltage applied by a high voltage electrode 6 but, in order to prevent the fine particles of wax from solidification by cooling, the atmospheric temp. in the chamber 8 is held to the m.p. of wax or more. By this method, if the plated steel plate, to which molten wax is uniformly sprayed, is led out from the chamber 8 and cooled, the plated steel plate having the wax solidified film can be supplied to a molding process as it is.

Description

[Detailed description of the invention] (Technical field) Kibatsu F! f4 relates to a method for treating aluminum-zinc alloy coated steel sheets with wax.

(Background technology) Aluminum-zinc, lead alloy plated steel sheet contains 4 to 75% by weight of aluminum, most of the rest is zinc, and S11
This is a copper plate plated with an alloy containing a trace amount of a third component such as Mg5CeLa. Currently commercialized products include low aluminum-zinc alloy plated steel sheets plated with an alloy containing 4 to 10% by weight of aluminum, most of the remainder being zinc, and a small amount of Mg or Ce-La; 55% by weight and 43% zinc.
There are two types: a high aluminum-zinc alloy plated steel sheet plated with an alloy containing 4% by weight and 1.6% by weight of Si. Compared to commonly used hot-dip galvanized steel sheets, when the thickness of the plating layer is the same, low aluminum-zinc alloy coated steel sheets are 1.5 to 2 times more corrosion resistant, and high aluminum-zinc alloy coated steel sheets are 3 to 3 times more corrosion resistant. It has 6 times better properties. Furthermore, high aluminum-zinc alloy plated steel sheets are excellent in K1-4 heat resistance and heat reflectivity. Aluminum-zinc alloy plated steel sheets have recently attracted particular attention due to their excellent properties, and are used in construction products such as roofing and wall materials, civil engineering products such as guardrails, soundproof walls, snow fences, and drainage ditches, and automobiles. It is rapidly becoming popular as a material for home appliances, industrial equipment, etc., and even as a substrate for painted steel sheets.

However, since the aluminum-zinc alloy coated steel sheet contains aluminum in its plating layer, its hardness is lower than that of the hot-dip galvanized steel sheet. Since the plating layer of the aluminum-zinc alloy plated steel sheet is hard, it is difficult to connect the aluminum-zinc alloy plated steel sheet to forming rolls or press dies when processing it by zero-roll forming or press forming. Due to poor lubricity, the coating layer may be destroyed, or the coating layer may be fused to the forming roll or press die due to the frictional heat between the two, and as a result, the aluminum-zinc alloy plated steel sheet may be removed. The metal powder will adhere to the forming rolls and press molds, and the metal powder will accumulate on some tilted corners of the molded product, causing a seizure phenomenon and causing defects such as scratches and abrasion, resulting in changes in appearance. There is a possibility that this may occur.

Conventionally, in order to avoid such problems, lubricating oil that is liquid at room temperature is applied to the surface of the aluminum-zinc alloy plated steel sheet during forming processing by spraying or zero coating, and then lubricating oil is applied to the forming rolls and press dies. was applied to provide lubricity to the surface of the aluminum-zinc alloy plated steel sheet to improve the slippage between the aluminum-zinc alloy plated steel sheet and forming rolls and press dies.

However, when forming aluminum-zinc alloy plated steel sheets using lubricating oil, the forming rolls and press dies are coated with lubricating oil, so it is difficult to use the surface-coated steel sheets after this process. When molding is performed through a molding tool or press mold, lubricating oil may adhere to the coated surface of the copper plate and contaminate it, or metal powder generated during molding may adhere to the painted surface due to the lubricating oil. Therefore, to prevent such contamination, molding
- A problem arises in that cleaning of the molds and press molds is required. Further, in order to prevent the occurrence of rust due to moisture during storage, the plated surface of aluminum-zinc alloy plated steel sheets is subjected to zero-metal treatment in the same manner as in the case of hot-dip galvanized steel sheets. Aluminum-zinc alloy coated steel sheets are considerably more resistant to rust than hot-dip galvanized steel sheets, but when rust occurs, unlike the white rust-like appearance of hot-dip galvanized steel sheets, aluminum-zinc alloy coated steel sheets are more resistant to rust than hot-dip galvanized steel sheets. Since the steel plate develops a gray to black color and significantly impairs its appearance, it is treated with 0m, but in this case, when treating the aluminum-zinc alloy plated steel plate with lubricating oil. If the lubricating oil is a water-soluble lubricating oil, there is also the problem of contamination due to the elution of zero mate.

(Object of the Invention) The present invention has been made in view of the above points, and is capable of forming a film containing a lubricating oil that is solid at room temperature on the surface of an aluminum-zinc alloy plated steel sheet, thereby removing the lubricating oil. The purpose of the present invention is to provide a method for surface treatment of aluminum-zinc alloy plated steel sheets, which can be subjected to zero-roll forming or press forming without the need for using aluminum alloys, and which can uniformly form a lubricating film. It is.

(Disclosure of the Invention) According to the surface treatment method of the aluminum-zinc alloy plated steel sheet according to the present invention, the surface of the aluminum-zinc alloy plated copper plate is coated with a wax that is solidified at room temperature at an ambient temperature higher than the melting temperature. It is characterized by forming a lubricating film on the surface of an aluminum-zinc alloy plated copper plate by rapidly spraying molten wax.
Kibatsu 11JJ will be explained in detail below.

The wax used in the present invention is mineral oil-based, for example, paraffin-based, and has a melting temperature of 60 to 60.
It is solid at room temperature of 100°C. Of course, it can be used alone, but it can also be used by mixing it with heavy oil lubricating oil such as cylinder oil. It needs to be solid. This wax ill is heated and melted and applied to the surface of the aluminum-zinc alloy plated copper plate.
The one shown in the figure can be used. That is, in Fig. 1, after (5) is sprayed, (6) is the high voltage electrode, and (7) is the high voltage electrode.
) are electrode supporting insulators, which are arranged in the chamber (8). (9) is the Jato board, 1101 is the sword guide board, and (II) is the rJ guide board. The basic structure of the sprayer (5) is as shown in Figure 2, in which heated and melted wax (1) is supplied into a tank.
The lower part of the grooved 0-ra θ is immersed in wax (1), and the rotational speed of the grooved 0-ra 1 is variable. A plurality of longitudinally inclined grooves are provided in this grooved O-ra α, and a plurality of nozzles 4 are arranged corresponding to the grooves. Therefore, pick up the molten wax (1) and stop it at the lower part of the nozzle (particularly the bottom nozzle θ), and send the heated air to the branch pipe 05.
, the molten wax (1) sucked into the suction pipe Q81 is ejected from the spout (17) of the nozzle α through the jetter (I), and the molten wax (1) sucked into the suction pipe Q81 is jetted out together with air, turning the molten wax into fine particles. In this device, the amount of molten wax (1) picked up can be controlled by changing the rotational speed of the grooved 0-503) by synchronizing it with the feeding speed of the aluminum-zinc alloy plated steel plate. The amount of molten wax +11 applied can be made uniform or the amount of application can be changed freely.

Therefore, when surface-treating an aluminum-zinc alloy plated copper plate with wax, the steel plate is passed through a molten metal plating tank in a manufacturing facility for aluminum-zinc alloy plated steel plate to apply aluminum-zinc alloy plating, and then cooled. The shape is corrected using a surface shape correction device such as a temper rolling mill or a tension leveler, and the surface of this aluminum-zinc alloy plated steel sheet is first subjected to chromate treatment if necessary. To perform the 0-metal treatment, apply a reactive 0-metal solution to the surface of the aluminum-zinc alloy plated steel plate using a spray or dipping bath and adjust the amount of application using a 0-ru aperture, or use a 0-ru coater. Coating drying mold 0
This is done by applying a mate solution and drying it to form a film using a hot air dryer, far-infrared heating device, etc. The amount of chromium deposited on one side is 5 to 50mf.
It is best to adjust it so that The aluminum-zinc alloy plated steel sheet thus treated is sent to a coating device as shown in Fig. 1, and while passing through a chamber (8) as shown by the arrow, it is transferred from a sprayer (61) to a sprayer (61). Molten wax is sprayed onto both the top and bottom surfaces of an aluminum-zinc alloy plated steel sheet. At this time, due to the high voltage applied by the high voltage electrode It is applied to the surface of Mu zinc alloy plated steel sheet.
The fine particles of molten wax coming out of the nozzle 01 in step 6) are cooled and hardened in the chamber (8)), and do not adhere well and evenly to the aluminum-zinc alloy plated steel sheet, making it impossible to form a uniform film. F; becomes a white or yellow-white opaque film. Therefore, in the present invention, the temperature of the atmosphere in the chamber (8) is maintained at a temperature higher than the melting temperature of the wax, and the molten wax is thinned out from the nozzle of the spray plate (5). This is to prevent the grains from cooling and solidifying before they are attached to the aluminum-zinc alloy plated steel sheet.The surface of the aluminum-zinc alloy plated steel sheet is also heated with a far-infrared heater, hot air, propane gas flame, etc. The attached wax may be remelted to form a transparent film, or the aluminum-zinc alloy plated steel sheet may be preheated and sent into the chamber (8). The amount of wax attached to the surface is 0.3 to 5
f/ln' is preferred. In order to control the amount of wax deposited in this way, the grooved roller Oi is
51, 5F5-51, VSt-1, is rotatably driven by a variable speed drive device such as a hydraulic motor to adjust the rotational speed of the grooved 0-layer and the pressure of the air ejected from the nozzle (I9). , adjust the voltage of the high voltage electrode (6) in electrostatics, and even adjust the pitch of the nozzle On and the grooved 0-
This can be done by adjusting the spacing and number relationship between the 50 grooves and the nozzles Q9).

The aluminum-zinc alloy plated steel sheet onto which the molten wax has been sprayed is taken out from the chamber (8) and cooled to solidify the wax and form a film on the surface of the aluminum-zinc alloy plated steel sheet. It is then wound onto a tension reel. This film may be formed on both sides of the aluminum-zinc alloy plated steel sheet, but it may also be formed on only one side.However, the film made of wax, which is solid at room temperature, has lubricating properties. D-
This makes it possible to form aluminum-zinc alloy plated steel sheets while ensuring lubricity during forming processes such as molding and press forming to prevent seizures, scratches, and gamma rays. Even when a steel plate is subjected to 90 mate treatment, there is no fear that it will act on ro mate, unlike in the case of liquid lubricating oil.

Moreover, this film is solid at room temperature and will not adhere to the o-ru or press mold. Furthermore, the solid wax film treated on the surface of aluminum-zinc alloy plated steel sheets in this way is easily removed during the degreasing process after forming, and aluminum-zinc alloy plated steel sheets can be used as roofing and wall materials. When used as an adhesive, it will be naturally peeled off in a short time by rainwater. In addition, when painting aluminum-zinc alloy plated steel sheets after forming, it is easy to sand them with sandpaper before painting.
fAJNi is removed.

Next, the present invention will be specifically explained with reference to examples.Example: As an example aluminum-zinc alloy plating M#L, the composition of the plating layer is A/=55% by weight, Zn=43.4% by weight, 5i -1.6% by weight, the amount of plating on one side is 'lo'
In t/d, board width'? + 4. , a plate with a thickness of 0.8-=- was used, and the amount of chromium deposited was 20m on one side. / n
0 meter treatment was carried out due to the adhesion amount of f. This aluminum-zinc alloy plated copper plate was passed through the coating apparatus shown in FIGS. 1 and 2, and microwax having a melting temperature of 90° C. was sprayed and electrostatically coated. The ambient temperature inside the chisemper was 120 °C, and the amount of microwax applied was 2 f/nl on one side. After the wax was sprayed in this manner, the aluminum-zinc alloy plated steel sheet was cooled to form a film formed by assimilation of the wax.

The thus surface-treated aluminum-zinc alloy plated steel sheet was formed at a forming speed of 50 m/min.
0 m through, cross-sectional shape as shown in Figure 3, mountain height h1
A folded plate roof with a length of 130 mm and a working width of 550 mm was formed.

There were no burns, scratches, or aggregations on the surface of the molded product formed in this way, and there was no adhesion of metal powder on the surface of the forming roll that had peeled off from the plating layer of the aluminum-zinc alloy plated steel sheet. Immediately after forming in this way, a white-painted steel sheet was passed through the same forming roll, and the white-painted steel sheet did not show any stains, indicating that the aluminum-zinc alloy It was confirmed that the coating applied to the surface of the plated steel sheet did not adhere to the forming roll.

(Effects of the Invention) As described above, in the present invention, the surface of the aluminum-zinc alloy plated steel sheet is lubricated by spraying molten wax that is solid at room temperature onto the surface of the aluminum-zinc alloy plated steel plate. Since it is designed to form a sticky film, there is no need to use liquid lubricating oil to obtain lubricity like in the past, and the lubricity between the rolls and press molds is achieved by a film made of solid wax. Aluminum while ensuring the prevention of burning, scratches, and abrasion. I1
This machine is capable of forming 1-lead alloy plated steel sheets. Moreover, when spraying wax that is solid at room temperature in a molten state, the spraying is performed at an ambient temperature that is higher than the melting temperature of the wax, so the fine particles of the sprayed molten wax do not solidify. It reaches and adheres to the aluminum-zinc alloy plated steel sheet in a molten state, and it is possible to uniformly apply a wax film.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of a wax coating device used in the present invention, Fig. 2 is a sectional view showing the structure of the sprayer in the same, and Fig. 3 is a sectional view showing the shape of a molded product. (]) is wax. Agent Patent Attorney Ishi 1) Chief 7th Prisoner

Claims (1)

[Claims] +11 Surface K of aluminum-zinc alloy coated steel sheet, forming a lubricating film on the surface of the aluminum-zinc alloy coated steel sheet by spraying a molten wax that is solid at room temperature under an ambient temperature above the melting temperature of the wax. A method for surface treatment of aluminum-zinc alloy coated steel sheet, characterized by