JPS6173880A - Method and device for plating by vacuum deposition - Google Patents

Abstract

PURPOSE:To obtain a plated product having good film strength by providing nitrogen replacing chambers between an annealing furnace and vacuum sealing devices and controlling the pressure and hydrogen concn. in the nitrogen replacing chambers. CONSTITUTION:The inlet side nitrogen replacing chamber 3 is provided between the inlet side vacuum sealing device 5 in front of a vacuum deposition chamber 7 of a plating device by vacuum deposition and the annealing furnace 2. The outlet side nitrogen replacing chamber 8 is provided between the outlet side vacuum sealing device 5 behind the chamber 7 and the atm. A circulating and refining device 12 for gaseous N2 which circulates the gaseous N2 from the devices 5 toward the chambers 9 and removes the water, oil and oxygen in the gaseous N2 is provided between both vacuum sealing devices and the chambers 9 under the atmospheric pressure of both vacuum sealing devices. The pressure P1 in the furnace 2 is controlled to the atmospheric pressure or above, the pressure P2 of the chamber 3 to the atmospheric pressure or above and the pressure P3 of the chamber 8 to the atmospheric pressure or above to satisfy the equation. The hydrogen concn. in the chamber 3 is con trolled to <=20%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum evaporation plating method and a vacuum evaporation plating apparatus.

[Conventional technology]

In the vacuum evaporation plating method, in order to prevent dust etc. from entering the vacuum chamber from the atmospheric pressure side, 1. Conventionally, an annealing furnace and a vacuum chamber are used together with a means to gradually reduce the pressure from atmospheric pressure to create a vacuum in stages. It has been proposed to provide a chamber with a high-pressure inert gas atmosphere between them (see Japanese Patent Publication No. 44-6576 and Japanese Patent Application Laid-Open No. 55-85742).

By the way, when performing vacuum evaporation plating, the adhesion strength of the film between the steel strip and the plated metal is such that peeling, cracking, or padding will not occur even when subjected to severe processing such as I B ooot bending or reverse redrawing bending. Must-have. For this purpose, the steel strip is annealed and reduced in an atmosphere of hydrogen gas (5 to 75%) to create an active surface that provides sufficient film adhesion strength for the plated metal even when vacuum evaporated. This objective can be achieved by guiding the steel strip through a vacuum chamber and into a vacuum deposition chamber while maintaining this surface quality.The above-mentioned conventional proposal was to install a high-pressure chamber to prevent dust from entering the vacuum chamber. Although the purpose is to prevent this, it is not possible to obtain the desired vacuum-deposited plated product with this method alone.In other words, if the annealing furnace (atmospheric pressure + 5 to 1011 IIAq) for annealing and reducing the steel strip is directly connected to the vacuum chamber, It is not possible to evacuate the hydrogen gas% -5 to 75% in the annealing furnace.If the vacuum is broken and air (oxygen gas) enters, there is a risk of explosion, and it is not practical for industrial use. .

[Problem that the invention seeks to solve]

The present invention provides the following advantages: without impairing the original functions of the annealing furnace and vacuum chamber
It is an object of the present invention to provide a vacuum evaporation plating method that solves the above problems and a vacuum evaporation plating apparatus for implementing the method.

[Configuration of the present invention]

That is, the present invention provides the following features: (1) An inert gas substitution chamber is provided between the inlet side vacuum sealing device in front of the vacuum evaporation plating chamber and the annealing furnace, and an outlet side vacuum sealing device is provided after the vacuum evaporation plating chamber. An inert gas exchange chamber on the outlet side is provided between the re-vacuum sealing device and the atmospheric pressure chamber of the re-vacuum sealing device. In a vacuum evaporation plating equipment equipped with an inert gas circulation purification device that circulates active gas and removes water, oil, and oxygen from the inert gas, the pressure inside the annealing furnace is set to above atmospheric pressure and the inlet side is heated. The pressure P1 inside the active gas replacement chamber is equal to or higher than atmospheric pressure, the pressure P1 inside the inert gas replacement chamber on the outlet side is equal to or higher than atmospheric pressure, PI-P,
A vacuum evaporation plating method characterized by controlling the hydrogen concentration within 2-0% or less within the range of inert gas substitution on the side of ≧0 bait, (2) Vacuum on the entrance side in front of the vacuum evaporation plating chamber. An inert gas exchange chamber on the inlet side is provided between the sealing device and the annealing device, and an inert gas exchange chamber on the outlet side is provided between the vacuum sealing device and the atmosphere on the outlet side after the vacuum evaporation plating chamber. Between the vacuum sealing device and the atmospheric pressure chamber of the revacuum sealing device, an inert gas is circulated from the revacuum cooling device to the atmospheric pressure chamber, and water, oil, and oxygen in the inert gas are removed. A vacuum evaporation plating apparatus equipped with an inert gas circulation fJ device for removal (a pressure gauge is installed in the annealing furnace,
A pressure gauge, control valve, automatic valve, hydrogen concentration detector, and release valve are installed in the inert gas exchange chamber on the inlet side, a pressure gauge and automatic valve are installed in the inert gas exchange chamber on the outlet side, and an atmospheric pressure chamber of the re-vacuum sealing device. The present invention relates to a vacuum evaporation plating apparatus characterized in that each of the vacuum evaporation plating apparatuses is provided with an automatic valve that communicates with an emergency inert gas tank.

Specifically, the present invention provides a nitrogen substitution chamber between an annealing furnace and a vacuum sealing device, and also provides a vacuum seal between the annealing furnace and the nitrogen substitution chamber and between the nitrogen substitution chamber and the vacuum sealing device. Seal rolls with the same specifications as the seal rolls used in the device are arranged. The annealing furnace is characterized in that the pressure in the annealing furnace and the pressure in the nitrogen substitution chamber are equal to each other, or that the pressure in the annealing furnace is slightly higher than the pressure in the nitrogen substitution chamber. In other words, if the pressure is the same, hydrogen gas will not flow from the annealing furnace into the nitrogen substitution chamber, and therefore there will be no risk of an explosion due to an increase in the amount of hydrogen in the nitrogen substitution chamber, and nitrogen gas will not flow from the nitrogen substitution chamber into the annealing furnace. Atmospheric gas from the annealing furnace (cod 5 to 7) leaked out and
5%, N1-95 to 25%)) It is also possible to eliminate the occurrence of zones in the annealing furnace that do not satisfy the conditions and problems in annealing reduction.

In addition, in the present invention, the seal roll has a structure in which the gas passage area is extremely small, and the gas flow rate is under choke conditions (when the pressure ratio of low pressure / high pressure is less than cL52).
However, it has a tight structure with little H gas. Therefore, when the pressure is equal, there is no gas flow, and even if there is a differential pressure that slightly increases the pressure on the annealing furnace side, the amount of leakage due to the gas flow is so small that it can be ignored. Hydrogen gas diffuses into the nitrogen substitution chamber through a small gap between the seal rolls.

Similarly, there is gas movement due to nitrogen gas diffusing into the annealing furnace.

The steel strip annealed and reduced in an annealing furnace has an active surface that allows vacuum evaporation plating, but since the activity of the steel strip is lost in the nitrogen purge chamber, hydrogen gas is released due to diffusion. It is preferable to move to the nitrogen substitution chamber, and the pressure in the annealing furnace is raised slightly so that some hydrogen gas leaks into the nitrogen substitution chamber, so that the amount of hydrogen in the nitrogen substitution chamber is 20% or less, preferably 12 to 2.0%.
Another feature of the present invention is that the hydrogen content in the nitrogen replacement chamber exceeds 2% and reaches a value that poses a danger of explosion, in which case nitrogen gas is introduced into the nitrogen replacement chamber. When the pressure in the nitrogen replacement chamber rises due to dilution, the atmospheric gas of nitrogen gas and hydrogen gas is released from the release valve, and the amount of hydrogen gas in the nitrogen replacement chamber is reduced to a weakly reducing atmosphere, that is, H≦λ05, preferably %- It is characterized in that it is controlled to CL2 to λO%.

As is clear from the above, in the vacuum evaporation plating method of the present invention, the reason why the pressure P1 in the annealing furnace is set to above atmospheric pressure is because the atmospheric gas in the annealing furnace is This is because there is a risk of explosion when oxygen (air) enters the annealing furnace, so the pressure in the annealing furnace must always be controlled to be above atmospheric pressure. In general, Pi - atmospheric pressure +
It is preferable to control the annealing furnace to 5 WAq (for example, the inlet of the annealing furnace is heated with a direct burner (non-oxidizing furnace), and the pressure from the combustion exhaust gas is obtained. In other words, the pressure of the entire annealing furnace is Since the atmospheric gas is constantly supplied with FK, it is possible to obtain a pressure higher than atmospheric pressure, preferably atmospheric pressure, +5 mAq).

Also, the reason why the pressure P in the inert gas exchange chamber on the inlet side is set to be higher than atmospheric pressure is to prevent air from entering. Gas replacement chamber pressure P! Atmospheric pressure +5 ~ 41111I
Let it be Aq. That is, an inflow of 5 to 75% of the atmosphere gas on the annealing furnace side into the exchange chamber, and 95 to 25% of N, 5W, t-
This is to control the atmospheric gas in the replacement chamber to 4≦zO%, preferably to α2 to λ0%, and N8Il1199.8 to 98%.

Furthermore, the pressure P1 in the inert gas exchange chamber on the outlet side is set to above atmospheric pressure, preferably atmospheric pressure + 5 mAq, generally to prevent air from flowing in, but the present invention has the following functions and effects. It's to get it. One is inert gas nm
The second is to prevent air from entering the system, and the second is to prevent oxidation (blueing) of the non-plated surface if air (oxygen) accumulates in the inert gas exchange chamber on the outlet side during single-sided plating. (Note that the inert gas exchange chamber on the outlet side also serves to cool the steel strip.)

In addition, the above-mentioned No-Crow≧OmAq is defined as Crow and P! is above atmospheric pressure, P≧atmospheric pressure, and ≧≧, but Pl is preferably atmospheric pressure + 54 muq, so
P! In order to achieve ≧atmospheric pressure, P8-P and ≧0 cod Aq were set. In addition, if more than 2.0% of inert gas flows into the inert gas exchange chamber from the annealing furnace, N is introduced into the exchange chamber to dilute it, but at this time, it is released when R-Pg < O. Control operates to open the valve and maintain 义-P≧0.

Hereinafter, the present invention will be explained in detail based on FIGS. 1 and 2. FIG. 1 is a diagram illustrating an example of a vacuum evaporation plating apparatus according to the present invention, and FIG. 2 is a diagram illustrating the apparatus according to the present invention in more detail.

In Fig. 1, a steel strip 1 is annealed in an annealing furnace 2, reduced with an atmospheric gas (4m5~75%, N! cod 95~25%), and with sealing rolls 4 on the front and back. ) into replacement room 5).

The nitrogen substitution chamber 3 is filled with hydrogen gas (H≦20%, preferably Hl-
(L 2 to 2.0%) controlled by a weakly reducing atmospheric gas. Next, it enters a vacuum sealing device 5 consisting of a plurality of seal rolls 4, a plurality of vacuum chambers 9 and an atmospheric pressure chamber 26, passes through a tar/dow 7a-roll 6, and then enters a vacuum deposition chamber 7.
The molten gold rA (not shown) is plated on the steel strip, and is led out of the vapor deposition system at atmospheric pressure through the vacuum sealing device 5 and the outlet nitrogen purge chamber 8.

Nitrogen gas exhausted by a vacuum exhaust system 11 consisting of a plurality of vacuum pumps 10 connected to each vacuum chamber of the vacuum sealing device is sent to a nitrogen fiflJ system 12, where the gas is converted to moisture and oxygen contained in the exhaust gas. , to remove oil and to make the purified gas a weakly reducing atmosphere gas, hydrogen gas is introduced into the system.
*5 Mix it to a concentration of z 0%, preferably Ht-12 to 20%, and place it in the atmospheric pressure chamber 2 of the vacuum sealing device.
Creating a vacuum by creating a circulation circuit that sends it back to 6・@2
In the figure, the pressure in the annealing furnace 2 is detected by the pressure gauge 13, the pressure at that time is defined as 0, and the pressure in the nitrogen e-true chamber 5 is detected by the pressure gauge 14.
The pressure at that time is 21. Nitrogen gas that initially filled the vacuum sealing device gL5 and the vacuum deposition chamber (not shown) is evacuated by the vacuum evacuation system 11 consisting of the vacuum pump 10, subjected to BIA in the nitrogen purification system 12, and passed through the piping 27 to the vacuum. It is returned to the atmospheric pressure chamber 26 of the sealing device 5 and evacuated again. At this time, the pressure difference (P) between the pressure P in the nitrogen substitution chamber 3 and the pressure P1 in the annealing chamber.

-P1≦OgAq), the pressure is controlled by releasing excess nitrogen gas from the release valve 32 into the atmosphere, and the vacuum inside the vacuum sealing device is maintained.

Annealing furnace atmosphere gas (
(Bird's eye 5-75%, N1's 95-25%) supply line (
(not shown), and the furnace pressure is controlled so that the pressure in the annealing furnace 2 is ≧atmospheric pressure, preferably -atmospheric pressure + 5fimq.

The pressure in the nitrogen substitution chamber 3 is P8≧atmospheric pressure, preferably P8=l
I Pressure gauge 1 so that atmospheric pressure +4~511+11AqK
Nitrogen gas 17 is sent to the nitrogen substitution chamber 3 via the control valve 16 and is controlled.

On the other hand, hydrogen gas leaking from the annealing furnace 2 is 4=2.0%
There is a danger of explosion if the hydrogen concentration detector 19 is exceeded.
is activated, the automatic valve 18 is activated, and the nitrogen gas 17 is introduced into the nitrogen substitution chamber 3 and diluted. In this case, the hydrogen concentration is H!
-1.0% or less, the automatic valve 18 will not close, and if the differential pressure P, + PI≦OgAq, the excess atmosphere in the nitrogen replacement chamber 3 will be released from the release valve 32. The gas is released into the atmosphere.

In addition, the pressure Pm of the outlet nitrogen substitution chamber 8 provided on the outlet side
11 pressure gauge 22, )≧atmospheric pressure, preferably P
, - Atmospheric pressure +5 HAq is controlled by supplying nitrogen gas 17 from an automatic valve 25.

In addition, the pressure PR in the nitrogen substitution chamber 3 and the pressure P in the nitrogen substitution chamber 8
If the pressure of s is P, < atmospheric pressure, e.g. P, ≦ atmospheric pressure - 5 mA
q, P3 (atmospheric pressure, e.g. Karasu≦atmospheric pressure - 5 area AqiC
- If the vacuum seal device malfunctions, the automatic valve 2
0 opens, nitrogen gas is supplied from the emergency nitrogen tank 21 to the vacuum sealing device, the pressure in the atmospheric pressure chamber 26 is returned to atmospheric pressure, and highly concentrated hydrogen gas enters the circulation system into the furnace 2.
At the same time, it prevents oxygen gas from flowing into the outlet nitrogen/R exchange chamber 8 from the atmosphere, and further prevents oxygen gas from flowing into the circulation system, thereby preventing an explosion of the entire station. prevention and safety is ensured.

The nitrogen substitution chambers 3 and 8 can be separated from each other for safety and each can be controlled to a desired pressure only when a gas-tight seal roll 4 is provided.

Although the present invention has been described in detail above, the present invention will be explained in more detail by giving specific examples of the present invention.

〔Example〕

Zinc was plated onto the steel strip using a vacuum evaporation plating method under the following conditions.

"ff Steel: Thickness 16 question board @ Tomi 3001 Threading speed: 20 g/mi!! Annealing furnace: Furnace pressure; Atmospheric pressure + 5 wa Aq Atmosphere gas: Horse bulk 75%, N, ! 25% N, substitution Chamber: Pressure; Atmospheric pressure +4
g Steel strip temperature in the Aq island replacement chamber: approximately 350 to 400°C
The temperature in the vacuum lidding chamber is 255℃, and the gas properties of the circulating purified gas at this time are false concentration: 3
ppm Water content 2 N point -62℃ Hydrogen! : α7% Oil weight: Oppm The plating was carried out under the conditions of: α7% Oil weight: Oppm, and the plating was applied while the activation of the steel strip was maintained in the vacuum sealing device.

As a result of zinc plating under the above conditions, vacuum evaporated zinc plating with good adhesion was obtained. The results are shown in FIGS. 3, 4, and 5.

That is, Fig. 5 shows the corrosion resistance test results of the vacuum evaporated zinc plating film by salt spray at the temperature of the strip steel before vacuum evaporation of 255°C, and Fig. 4 shows the results of the corrosion resistance test of the 255°C' strip steel shown in Fig. S. This shows a comparison of the salt spray corrosion resistance test results of galvanized products obtained by high-temperature vacuum evaporation plating method and galvanized products obtained by other plating methods. It shows that it is good. In addition, in FIG. 4, zvn (marked with ○ in the figure) is vacuum evaporation plating according to the present invention (same product as Δ in FIG. 3), l'G (marked with ○ in the figure),
×) indicates electroplating, II)G (in the figure, Δ) indicates hot-dip plating, and HD()mu (in the figure, ◇) indicates each product by alloying treatment of hot-dip plating.

Figure 5 shows microphotographs of the surface of the galvanized product obtained by the vacuum evaporation plating method at a strip steel temperature of 255°C and the galvanized product obtained by other plating methods, as shown in Fig. 5, and 180'o
The micrograph of the T-bending test shows the adhesion strength of the film, with no cracks observed at the bending part. Figure 5 (
4) Vacuum evaporation plating according to the present invention (strip temperature 255°C
LD ZVD) finished product (plating amount 542/yes”),
Figure 5 (5) is a KG product (plating amount 18 f7.2)
, Fig. 5 fcl is HDG product (plated [65f/mW
), Figure 5 q shows HDGA product (plated 1a4P/m
'') in each figure, [al] indicates the state of the crystal structure of the zinc plating on the surface, and Cb) indicates the state of the part indicated by the arrow in Fig. 6 of the 01 bending test.

[Effects of the present invention]

As described in detail above, the present invention provides an apparatus for performing vacuum evaporation plating, in which a nitrogen exchanger is provided between an annealing furnace for annealing and reducing a strip steel and a vacuum sealing device for creating a vacuum, and a nitrogen substitution chamber is further provided. Seal rolls should be provided at the inlet and outlet of the annealing furnace, and a chamber separate from the annealing furnace and vacuum sealing device should be created, and a nitrogen substitution chamber whose pressure should be controlled to be equal to or slightly lower than that of the annealing furnace. By providing this, it is possible to connect the annealing furnace and the vacuum sealing device, and the effect that vacuum evaporation plating becomes possible is produced.

In addition, in the present invention, by making the pressure in the nitrogen substitution chamber slightly lower than the pressure in the annealing furnace (for example, the differential pressure is about 1 + mAq), the atmospheric gas in the annealing furnace (-5 to 75%, horse-95 to 2
5%) into the nitrogen purge chamber, the hydrogen concentration in the atmospheric gas in the nitrogen purge chamber can be made into a weakly cyclic atmosphere of 12 to zO%, and the surface of the strip steel activated by the annealing process can be ■T' that maintains its properties! This has the effect that true vapor deposition plating can be performed in a vapor deposition chamber, and a plated product with good film strength at the corners of the plated gold can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating an example of a vacuum evaporation plating apparatus of the present invention, and FIG. 2 is a diagram illustrating the apparatus of the present invention in more detail. Figure 3 shows the results of corrosion resistance tests using salt water spray on vacuum-deposited galvanized products at different strip steel temperatures, Figure 4 shows the results of corrosion resistance tests using salt water wXi on galvanized products obtained by various plating methods, and Figure 5 Surface crystal structure of galvanized products by various plating methods and 0
1 shows the surface crystal structure of the bending test results, and FIG. 6 is a diagram showing the OT bending test procedure of FIG. 5. 1-Strip steel 15,14.22-Pressure gauge 2-Annealing furnace 16-Control valve 5-Nitrogen substitution chamber 17-Nitrogen gas 4-Seal roll 18*20,25-Automatic valve 5-Vacuum sealing device 19-Hydrogen concentration Detector 6 - Turndown roll 21 - Nitrogen tank 7 - Vacuum deposition chamber 26
-Atmospheric pressure chamber 8-Nitrogen outlet 27-Piping 101-Vacuum pump 32-Discharge valve 11-Evacuation system 12-Nitrogen rlI system distribution agent 1) Clearance agent Ryo Hagihara - Figure 1 Corrosion; Storage (g, /ITL2) Corrosion fi) Weight loss (9/-zip needle 6 III CA) (o-on, 15m (A
) (Tsurai 5 diagram B) C illusion O 6 diagram (B) CbJ Sai 9 diagram (C) (b) Fang 5 diagram (D) (ku) to J~1

Claims (2)

[Claims] (1) An inert gas replacement chamber is provided between the inlet side vacuum sealing device in front of the vacuum evaporation plating chamber and the annealing furnace, and an outlet is provided between the outlet side vacuum sealing device after the vacuum evaporation plating chamber and the atmosphere. providing side inert gas replacement chambers, and circulating inert gas from both vacuum sealing devices to the atmospheric pressure chambers between the two vacuum sealing devices and the atmospheric pressure chambers of the two vacuum sealing devices; In a vacuum evaporation plating apparatus equipped with an inert gas circulation purification device that removes water, oil, and oxygen from the inert gas, the pressure P_1 in the annealing furnace is set to above atmospheric pressure and the pressure in the inert gas exchange chamber on the inlet side. P_2 is above atmospheric pressure, pressure P_3 inside the inert gas exchange chamber on the outlet side is above atmospheric pressure, P
_1-P_2≧0mmAq, a vacuum evaporation plating method characterized by controlling the hydrogen concentration in the inert gas replacement chamber on the inlet side to 2.0% or less. (2) An inert gas replacement chamber is provided between the inlet side vacuum sealing device in front of the vacuum evaporation plating chamber and the annealing furnace, and an outlet is provided between the outlet side vacuum sealing device after the vacuum evaporation plating chamber and the atmosphere. providing side inert gas replacement chambers, and circulating inert gas from both vacuum sealing devices to the atmospheric pressure chambers between the two vacuum sealing devices and the atmospheric pressure chambers of the two vacuum sealing devices; and a vacuum evaporation plating apparatus equipped with an inert gas circulation purification device for removing water, oil, and oxygen from the inert gas, a pressure gauge in the annealing furnace, a pressure gauge in the inert gas exchange chamber on the inlet side, and a control device. A valve, an automatic valve, a hydrogen concentration detector and a release valve, a pressure gauge and an automatic valve in the inert gas replacement chamber on the outlet side, and an automatic valve that communicates with the atmospheric pressure chamber of both vacuum sealing devices and an emergency inert gas tank. A vacuum evaporation plating apparatus characterized in that each of the following is provided.