JPS5913077A - Chemical conversion treatment of metallic surface - Google Patents

Abstract

PURPOSE:To control the contact time between a band steel and a treating soln. and to control freely the thickness of the chemical conversion film on the surface of the band steel in the stage of treating the surface of the band steel with a chemical conversion treating soln., by making a device for dipping the band steel into said treating soln. movable. CONSTITUTION:A chemical conversion treating soln. 2 is filled in a long treatment tank 1, and a band steel A to be treated is passed continuously in the soln. 2, whereby the surface thereof is subjected to a chemical conversion treatment. A device 3 for dipping the band steel consisting of a roll 5 which supports the steel A above the treating soln. and a roll 6 which curves and guides the steel A downward and dips the same into the soln. 2, and a takeout device 4 for the band steel provided with similar rolls 7, 8 are provided in this case, and one or both of the devices 3, 4 are moved so as to be attached or detached to or from each other, whereby the contact time between the steel A and the chemical conversion treating soln. is controlled and the thickness of the chemical conversion film on the surface of the band steel is controlled freely. A riser 35 provided with many nozzles is provided in the bottom of the treatment tank and the treating soln. is injected therefrom, whereby sludge is expelled into a recovery tank 32 and the deterioration of the chemical conversion film owing to the sludge is prevented.

Description

[Detailed description of the invention]

The present invention is a metal surface chemical conversion treatment apparatus, more specifically, when a metal strip is continuously conveyed and subjected to chemical conversion treatment by dipping, the contact time of the metal surface with the chemical conversion treatment solution can be controlled by a novel method. Regarding equipment. Conventionally, when strip metal is subjected to continuous chemical conversion treatment using the immersion method,
In order to adjust the amount of chemical conversion coating by changing the contact time between the metal surface and the chemical conversion treatment solution, it has generally been adopted to change the immersion passage speed of the metal surface in the chemical conversion treatment solution. The present invention also relates to varying and adjusting the contact time of the metal surface with the chemical conversion treatment liquid. As a technology that can provide even more flexibility,
No. 80 discloses the invention. According to this invention,
The contact time is adjusted by varying the length of the immersion zone of the conversion treatment liquid through which the metal surface is immersed. In addition, as a chemical conversion treatment device that can change the length of the immersion area, (a) a movable device that can move in parallel to the length direction (and the moving direction of the metal surface) within the treatment tank of a predetermined length A partition wall is provided, and a chemical conversion treatment liquid is accommodated in an immersion area formed on either side of the partition wall,
A device that adjusts the contact time by moving the partition wall while conveying the metal surface through openings provided in both the front and rear walls of the processing tank and the partition wall; A fixed intermediate wall is provided, a chemical conversion treatment solution is stored in some of the immersion areas formed by the intermediate wall, and the chemical conversion treatment is carried out while conveying the metal surface through openings provided in both the front and rear walls and the intermediate wall of the treatment tank. a device for adjusting the contact time by varying the number of immersion zones containing liquid; (C) providing a treatment tank of a predetermined length with a plurality of collapsible walls transversely dividing the same, some of the walls; A chemical conversion treatment solution is stored in the immersion area formed in communication by the folding of the treatment tank, and the metal surface is conveyed through openings provided in both the front and rear walls of the treatment tank and the unfolded wall, while changing the number of folded walls. (d) the treatment tank comprises at least two movable parts telescopically fitted together, containing a chemical conversion solution therein, through openings in the front and rear walls of the treatment tank; The above invention discloses an apparatus that adjusts the contact time by displacing the movable part while conveying the metal surface.Thus, the above invention is capable of adjusting the length of the immersion area itself, in other words, the length of the immersion area itself, in other words, the By changing the length of the tank, the contact time of the metal surface with the chemical conversion treatment solution can be adjusted.However, in each of the above devices, the movable member is

[For example, since the partition wall of FA, the collapsible wall of C1, and the two movable parts of DL come into direct contact with the chemical conversion treatment solution, their smooth movement may not be ensured due to adhesion of generated sludge, etc. Since the nature of the device is similar, it is not appropriate to actually use the device industrially.In addition, the inside of the treatment tank is divided into multiple parts, and one of the metal surfaces passing through is installed not only on the front and back walls of the treatment tank but also on the dividing means. Providing an opening in the chamber only complicates the device.Furthermore, it requires another processing liquid tank to catch the processing liquid leaking from the openings on both the front and back walls of the processing tank, so that the so-called double Since the tank (4) must be constructed, the device becomes complicated as well.Therefore, from the above points, it is recognized that it is difficult to apply the above invention to an industrial advantage. This solves the problem, and in contrast to the conventional technology that controls the contact time of the metal surface with the chemical conversion treatment solution by changing the length of the immersion region itself, this method changes the immersion length of the metal surface itself with respect to the immersion region. According to the present invention, a treatment tank of a predetermined length (i), a treatment tank ( 1) Means (11) for bending and guiding the strip-shaped metal surface, which is continuously conveyed horizontally along the length thereof, downward and immersing it in the processing solution; A means (1v) for bending and guiding the metal surface upward to take it out from the processing liquid, a means (1v) for horizontally moving the immersion means and/or the ejection means +110 to relatively approach or separate them (1v), and during immersion passage. A nozzle riser means M attached to the processing tank (1) for spouting the processing liquid so that the processing liquid near the metal surface flows along the metal surface conveyance direction.
Provided is a metal surface chemical conversion treatment apparatus characterized by comprising: Next, the apparatus advantageous to the present invention will be specifically described with reference to the accompanying drawings. In FIGS. 1 to 3, the treatment tank (1) may be a box-shaped tank having a predetermined length as shown by 1 in the figure, in which the chemical conversion treatment liquid 2 is stored and immersed for a predetermined length. area is configured. A is a band-shaped metal that is continuously conveyed horizontally over the length of the tank 1, and is immersed in the processing solution at the left side (in the drawing) of the tank 1, and is transported horizontally within the tank 1. After passing through the immersion state, it is taken out from the processing liquid at the right side of the tank 1 and transported as it is above the tank 1 toward the next process. The means (11) for injecting the metal A into the processing solution and the means (till) for removing it from the processing solution are indicated by 3 and 4, respectively. 5, and a roll 6 located behind the roll 5, which bends and guides the metal downward to allow it to penetrate and then presses it in the processing liquid.The extraction means 4 also basically consists of is composed of a front presser roll 7 corresponding to the roll 6, and a rear support roll 8 corresponding to the roll 5.The metal A, which is horizontally immersed in the processing liquid by the roll 6.7, is kept at the liquid level. It should be located within the range of about 10 to 30 lower fins.Therefore, if the diameters of each of the rolls 5 and 6°7.8 are appropriately selected, the diameter of the roll 1c, for example, the roll 6.
7 has a diameter of 25 ONIR or more), their respective rotating shafts (i.e., movable members) can be prevented from coming into contact with the processing liquid, so that the The problems of the above-mentioned known inventions are solved. The positional relationship between the rolls 5 and 6 or 7 and 8 is preferably large in terms of horizontal distance, for example, a distance of 1 m or more is sufficient. In the case of illustration based on such a viewpoint, the diameter of rolls 5 and 8 is 150 mm, the diameter of roll 6.7 is 250 mm, the horizontal distance is 1 m, and the entrance angle and take-out angle of metal A are respectively It is set so that it is 11 degrees. These angles are the (
7) It may be appropriately selected depending on the properties, but it is preferable to set it as small as possible in consideration of the ease of transportation of the metal A during the immersion treatment and the influence on the finished surface of the treatment. Moreover, the above-mentioned roll 5. 6. 7. 8 preferably has excellent chemical resistance, such as those made of commonly commercially available neoprene (polychloroprene) or hypalon (fluorosulfonated polyethylene), and preferably has a hardness of about 40 to 80. In order to change the immersion length of the metal surface in the treatment liquid in the invention, the above-mentioned infiltration means 3 and/or extraction means 4 are used.
horizontally to bring them closer together or farther apart. In the illustrated case, an example is shown in which the intrusion means 3 is movable and the extraction means 4 is fixed in position. The means [1v] for moving the infiltration means 3 may be configured as follows, for example. A moving frame 1 that positions the rolls 5 and 6 on both sides of the tank 1
1a and 11b to be rotatably supported. This moving frame lla has wheels 12 on the outside of its upper part.
a+ 13a has gears 14a, 153 on the outside of the bottom
are each rotatably provided. The wheel 12 (8) a+ 13a is engaged with a rail 17a with a cross-sectional shape provided on the lower surface of the horizontal frame 16a, and the gear 14a
llSa is engaged with a rack 19a provided on the top surface of another horizontal frame 18H. One of the gears 15a engages with the other gear 20a, which is connected via a speed reducer 22a to a reversibly rotatable electric motor 21a supported by a moving frame lla. The other moving frame llb also has members 12b to 12b corresponding to the members of the moving frame lla.
22b (partly not shown) is arranged, and the same mechanism is adopted. And the one-car electric motor is a moving frame lla,
It is designed to function in synchronization so that there is no deviation in the horizontal reciprocating motion of ILB. In addition, when the motion stop position of this immersion means 3 is set in advance, a normal relay circuit may be employed to automate changing the immersion length of the metal surface in the processing liquid. Furthermore, it goes without saying that the above-described configuration may be employed as is in order to make the extraction means 4 movable. The vertical support positions of the rolls 5 and 8 may be fixed, but the rolls 6 and 7 may be supported by normal means (
Advantageously, it is supported in a vertically movable manner, for example by means of hydraulic cylinders, pneumatic cylinders (not shown). When the roll 6.7 is lifted to release the pressure on the metal A, the dipping process is temporarily interrupted while the metal A is being conveyed, and the dipping means 3 is moved to change the dipping length of the metal A. This is because no load is applied to the metal A on the metal A, which is advantageous in terms of its mechanism, and also allows for smooth movement. Of course, in the case of the illustrated device, only the roll 6 may be supported so as to be movable up and down. In the invention having the above configuration, for example, after performing a predetermined immersion treatment between the infiltration means 3 and the extraction means 4 at the position indicated by the chain line in FIG. To adjust the contact time between the two, do the following: The rolls 6 and, if necessary, the rolls 7 are raised to release the pressers aligned with the metal A, and then both of the above-mentioned motors are driven to horizontally move and stop the infiltration means 3, and then the rolls 6. 7 to its original position and press the metal A into the processing liquid again. During this time, all personnel may or may not be in transit. According to the above non-invention, roll 5. 6. 7. Since movable members such as the rotating shaft in No. 8 can be arranged so as not to come into contact with the processing liquid, there is no need to adopt a special seal structure for them, and the contact time between the two can be changed by changing the immersion length of the metal surface in the processing liquid. Control can always be carried out easily. Moreover, since the treatment tank only needs to be box-shaped with a predetermined length, it is possible to control the contact time as described above.
There is no risk of complicating the structure. Furthermore, the control of the contact time can be carried out steplessly over the entire length of the treatment tank (i.e. the immersion zone). In the field related to the above-mentioned non-invention, high speed is generally employed for conveying the metal A. By the way, in the present invention, when such high-speed transport is carried out, depending on the speed, the metal floats above the processing liquid surface due to the buoyant force acting on the metal passing through the processing liquid, and the surface is exposed. There is a possibility that satisfactory processing cannot be achieved. In particular, when the relative speed difference between the metal passing through the immersion and the treatment liquid in the vicinity of the metal exceeds 100 m/min, the above phenomenon becomes remarkable. To eliminate this, the above relative speed difference should be 50 m/min or less, preferably 20 m/m.
It would be possible to reduce the transport speed to less than 100 m, but it is difficult to reduce the transport speed of the metal itself from the viewpoint of processing efficiency. Therefore, the present invention. Now let's try to solve this problem from another perspective. That is, the processing liquid near the metal during the immersion is moved in the same direction as the metal conveyance direction to take advantage of the above-mentioned relative speed difference. The means (v) for this purpose includes attaching the metal A to the inner wall and/or bottom of the front and both sides of the treatment tank so as not to interfere with the movement of the metal A, the infiltration means 3, and the extraction means 4.
A riser with a nozzle that sprays the processing liquid 2 backward is arranged,
What is necessary is just to adjust the spouting amount of the processing liquid due to this.

[12] The tank 1 shown in FIG. 1 is constructed in consideration of the above-mentioned points, and is additionally constructed so that sludge generated by chemical conversion treatment can be collected and taken out of the tank. That is, the tank 1 is configured in its longitudinal cross section so that the bottom 31 thereof slopes downward toward the rear as shown in the figure. This angle of inclination may be any angle at which the settled sludge can be moved satisfactorily, and generally may be appropriately selected within the range of 2 to 10 degrees. A recessed portion is formed at the bottom of the rearmost portion of the tank 1, and serves as a sludge recovery tank 32. Further, an overflow tank 34 is attached to the rear of the tank 34 via a drain 33. It is preferable that the sheath A3 is operable to adjust the height of the liquid level so that the metal A being immersed and passing through is located at an appropriate position below the liquid level. A riser 35 with a nozzle is arranged near the bottom 31 inside the tank. The risers 35 are arranged at appropriate intervals perpendicular to the length direction of the tank 1, and their nozzles are designed to eject the processing liquid toward the rear. The rearward flow of the processing liquid by the riser 35 is mainly focused on the accumulation of sludge, and the flow reaches zero at the bottom.
．． 3~], m/Sec has been found to be preferred. Due to the flow of this treatment liquid, the settled sludge is moved backward and accumulated in the recovery tank 32. The flow also reduces the relative speed difference of the nearby processing liquid to the transport speed of the metal during the immersion. Therefore, the spacing and number of risers 35, the shape and number of nozzles, the ejection pressure of the processing liquid, etc. may be appropriately selected within the range that achieves the above objectives. In addition, in order to compensate for the further decrease in the relative speed difference, for example, the treatment tank 1
Separate risers with nozzles (not shown) may be provided on both side walls of the tube. The riser 35 branches from a pipe 37 with a pump 36 that communicates with the side wall of the overflow tank 34, and is connected to a heat exchanger 38.
A single tube 39 is connected to the overflow tank 34 so that the processing liquid in the overflow tank 34 is supplied after being adjusted to a predetermined temperature. The temperature of the treatment liquid is adjusted by directly introducing steam into the tank 1 instead of using the heat exchanger 38, or by providing a flexible pipe in the tank 1 so as not to interfere with the chemical conversion treatment. Good too. At the bottom of the sludge collection tank 32 and the overflow tank 34, there are pipes 40 and 41, respectively.
are connected to these pipes 42, to which a pump 43 and a filter 44 are attached. Therefore, the sludge in the treatment liquid in the sludge recovery tank 32 and the overflow tank 34 is discharged to the outside of the system through the filter 44. On the other hand, the p liquid may be returned to the overflow tank 34 again, or, as shown in the figure, immediately after being supplied to a cleaning riser 45 provided at the position where metal A is taken out from the processing liquid. may be used to wash off residual sludge on metal surfaces to obtain a clean treated surface. The riser 45 may be provided not only on the upper surface but also on the lower surface of the metal A. Another pipe 46 branched from the above pipe 37
Another cleaning riser 47 is connected to. This riser 47 is placed above the metal A just before it is taken out from the processing solution, so that the ejected processing solution can sufficiently reach the metal A and remove the adhering sludge (" D
” Sea urchin. Thereby, the sludge adhering to the metal A can be prevented in advance from being pressed onto the metal surface by the roll 7. 48 is a lid provided on the tanks 1 and 34, and the duct 4
9 are erected. This duct 49 is provided with an eliminator 50 and a fan 51. Therefore, the mist and steam generated in the tanks 1 and 34 are sucked into the duct 49 by the fan 51, and the mist is transferred to the eliminator 5.
0 and collected in tanks 1 and 34, while the vapor is discharged outside the system. By providing this exhaust equipment, it becomes easy to adopt a closed circuit system in chemical conversion treatment that combines multi-stage water washing. Note that the duct 49 is preferably provided near the riser 47 where a large amount of mist is generated. Squeezing rolls (for example, 52) may be provided before and after the tank 1. In the present invention having the above configuration, conventionally known chemical conversion treatment liquids may be used, and iron, zinc, aluminum, and various alloys containing these as main ingredients may be used as the materials for all metals. sare(] 6) is sufficient. Next, specific examples of chemical conversion treatment will be given. Example 1 (See Figures 1 to 3) A treatment solution (total acidity 8, acid ratio 8, temperature 70°C) prepared using a commercially available zinc phosphate chemical conversion treatment agent (Granodin 46N-23J1 manufactured by Nippon Paint Co., Ltd.) was used. In the treatment tank containing 0
．． 3511M thick galvanized steel plate 60ffl/rnl
The chemical conversion treatment was carried out by moving the infiltration means 3 and adjusting the immersion time to 10 seconds while conveying at a speed of H. Film amount 1f/m. Next, the conveying speed of the galvanized steel sheet was changed to 90 m/min, and the soaking means 3 was moved to increase the soaking time to 5 months.
The chemical conversion treatment was performed in the same manner by adjusting the time to 2 seconds. The coating amount is 1f/m, and in this case, the treatment liquid in the tank is approximately 70m
It was circulated backwards at a speed of /min. As a result, the settled sludge in the tank is satisfactorily taken out of the system, and the relative velocity of the galvanized steel sheet to the treatment liquid during immersion is approximately 20
It became m/min. What is the performance of the chemical conversion treated board obtained in the above example? As shown in Table 1.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional side view showing an example of the uninvented device;
The figure is a partially omitted front view showing the main part of the infiltration means, and Fig. 3 is a partially omitted side view thereof. Support rolls, 6 and 7 are presser rolls, 11a+11b are moving frames, 35 is a riser with a nozzle, and 45.47 is a cleaning riser. Patent applicant: Nippon Paint Co., Ltd. Representative Patent Attorney Aoyama Aoyama and 1 other person

Claims (1)

[Claims] 1. A treatment tank (1) of a predetermined length that contains a chemical conversion treatment solution, and a band-shaped metal surface that is continuously conveyed horizontally above the treatment tank (1) along its length. Means (11) for bending and guiding the metal surface downward to penetrate the processing liquid, and means (11) for bending and guiding the metal surface horizontally passing through the processing liquid and taking it out from the processing liquid (
1111, means 6■ for horizontally moving the infiltration means (11) and/or the ejection means (between them) to relatively approach or separate them; A metal surface chemical conversion treatment apparatus comprising a nozzle-equipped riser means (v) attached to a treatment tank (1), which spouts a treatment liquid so as to flow along the treatment tank. 2. The infiltration means (1;) consists of a combination of a front roll means that supports the metal surface above the processing liquid and a rear roll means that presses it in the processing liquid, and an ejection means (ill) that presses the metal surface in the processing liquid. The device according to item 1 above, which consists of a combination of a front roll means and a rear roll means supported above the processing liquid.
The device according to item 1 or 2 above, wherein m) is fixed in position. 4. The device 58 according to any one of items 1 to 3 above, in which each of the press roll means of the intrusion means (11) and the extraction means 011) is movable up and down to the position where the press against the metal surface is released. The riser means (v) has a relative velocity difference of 50 m between the metal surface passing through the immersion and the processing liquid near the metal surface.
4. The apparatus according to any one of the above items 1 to 4, which ejects the processing liquid in a range of less than /min. 6. The bottom of the treatment tank (1) slopes downward toward the rear. The bottom of the rearmost part becomes a recess to form a sludge collection tank,
6. The apparatus according to any one of the above items 1 to 5, wherein the nozzle-equipped riser of means (v) is disposed on the inclined bottom so as to spray the processing liquid backward. 7. The apparatus according to item 3 above, which is equipped with a cleaning riser that spouts the treatment liquid toward the metal surface immediately before and/or after it is taken out of the treatment liquid.