JPS6277468A - Coating device for inside and outside surfaces of pipe - Google Patents

Abstract

PURPOSE:To easily form good films having no pores on the inside and outside surfaces of a metallic pipe by disposing the metallic pipe into a hermetic space and relatively moving a reactive gas introducing nozzle and the metallic pipe in the stage of introducing the reactive gas into the space and irradiating laser light to the gas. CONSTITUTION:A work 1 is installed in a pressure vessel 2 and after the inside of the vessel is evacuated, an inert gas is introduced through a valve 82 into the vessel 2 and valves 32, 38 are opened to introduce the reactive gas into the vessel from a pipeline 3. A control panel 20 is operated to irradiate the laser light 5 from a laser oscillator 25 via an optical fiber 26 to the reactive gas 4 and to induce a photochemical vapor deposition reaction. The work 1 is rotated at the same instant and the coating layers are formed on the inside and outside surfaces thereof. The coating layers which are dense and foamless and have excellent resistance to heat, corrosion and wear as well as having strength are thereby efficiently formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a coating device for the inner and outer surfaces of a tube, in which the gold mW surface is highly functionalized with, for example, ceramics.

[Conventional technology]

For example, oil country tubular goods are required to coat the inner and outer surfaces of gold G-tubes with ceramics, titanium, tungsten, or the like to improve the corrosion resistance, abrasion resistance, etc. of the tube surfaces. Traditionally, the typical methods for coating the inner and outer surfaces of metal tubes to make them highly functional are plasma spraying and arc build-up welding.◇ Plasma spraying uses an ultra-high temperature plasma jet to coat tungsten. This method involves melting powder of a high-melting point material such as powder and spraying it on the pipe surface at high speed to form a high-density and high-strength coating. In addition, the arc overlay welding method is a method in which corrosion-resistant weld metal is directly welded to the pipe surface to coat it. ◇ [Problems to be solved by the invention] In the above conventional plasma spraying method, high temperature and The atmosphere is drawn in by a high-speed plasma jet, m + 4−+
Small ridge soil Nakatomi also had the problem that the adhesion force weakened and at the same time minute pores were formed between the grains, making it impossible to obtain the desired performance in terms of corrosion resistance, etc. .

Point i - To solve the problem, put the nozzle and the part to be coated into a chamber and evacuate it, and then inject an inert gas such as argon to
A low-pressure plasma spraying method has also been developed in which plasma spraying is carried out by supplying at a low pressure of 40 Torr. When this low-pressure plasma spraying method is used, oxides are reduced and the porosity is also reduced, but these do not become zero, and the above-mentioned problems have not been completely solved.

Further, the arc overlay welding method had problems in that it had poor production efficiency and caused heat distortion.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a coating device for the inner and outer surfaces of a tube that can easily form a good coating without pores.

[Means for solving the problem] This issue 8JJ was made to solve the above problems, and it applies a coating layer to one or both of the inner and outer surfaces of the metal tube by photochemical vapor deposition reaction. In the coating equipment to be formed, a sealing means for placing the surface of the metal tube in a sealed space, a vacuum evacuation means for evacuating the sealed space,
A gas introduction means equipped with one or more nozzles for introducing a reaction gas into a space sealed by the vacuum evacuation means, and photochemical treatment by irradiating laser light onto the reaction gas introduced into the sealed space by the gas introduction means. The apparatus is equipped with a laser beam irradiation means for causing a target vapor phase deposition reaction, and a driving means for relatively moving the nozzle of the gas introduction means and the metal tube.

[For production]

In this invention, an antibinary gas that causes a photochemical vapor deposition reaction toward or along the surface of the workpiece is ejected from the pipe, and a laser beam is projected onto the reactive gas. The desired coating layer can be formed by causing a photochemical vapor deposition reaction. In addition, even if the workpiece is a metal tube, large or small, the workpiece surface can be sealed regardless of its internal or external shape, and a reactive gas can be introduced to cause a photochemical vapor deposition reaction. . Furthermore, the workpiece and the optical axis of the laser beam are configured to be movable relative to each other, and as a result, it is possible to perform the coding process over part or all of the inner and outer surfaces of the tube.

〔Example〕

FIGS. 1(a) and 1(b) are conceptual diagrams showing an embodiment of the present invention. In the figure, 1 is a workpiece to be inserted into a pressure vessel 2 to form a ' A control panel 20 controls a laser beam for causing a photochemical vapor deposition reaction, a laser oscillator 25° driving means 60, and the like.

26 is an optical fiber for guiding the laser beam 5 outputted from the laser oscillator 25 to a reactive gas, 30 is a cylinder containing a reactive gas (for example, SiH4, Tiet4', etc.), and 31 is a cylinder containing this reactive gas. 32 is a valve that opens and closes this conduit 31; 33 is a pressure gauge that indicates the pressure inside the conduit 31;
36 is its conduit, 67 is a pressure gauge that indicates the pressure inside this conduit, 80i
d other inert gases (e.g. Ar, Ha, Nθ,
81 is this cylinder 8.
a conduit for introducing an inert gas (for example, N2, etc.) in the pressure vessel 2 into the pressure vessel 2 and a purge gas for removing substances and dangerous gases that harm normal photochemical vapor deposition reactions;
2 is a valve that opens and closes this conduit, and 86 is a pressure gauge that indicates the pressure inside the conduit 81.

40 is a vacuum pump for evacuating the inside of the pressure vessel 2;
5 is a switching valve used for closing after evacuation is completed or removing the reactive gas 4 in the pressure vessel 2; 46 is a conduit for conveying the reactive gas 4 or the gas after the reaction to a safe place; 70 is an auxiliary valve for discharging the gas inside the pressure vessel 2, 71 is its conduit, 75 is a safety valve for the pressure vessel 2, 76 is a pressure gauge that indicates the pressure inside the pressure vessel 2, and 50 is a valve according to the size of the workpiece. 55 is a stand for changing the position of the tube 1I53 and the laser beam 5; A freely openable lid 66 is a mirror provided on the lid for scattering laser light.

Next, the operation will be explained. Now we need to process the outer diameter of the tube. First, open the opening/closing M65 and insert the workpiece 1. Next, the radius adjuster 50 is operated to set the laser beam 5 and the conduit 3 at predetermined positions near the workpiece 1. At this time, the valves 32, 38, and 82°70 are kept closed. Next, the opening/closing lid 65 is closed and the air inside the pressure vessel 2 is removed by the vacuum pump 40, and when the air removal is completed, the switching valve 4
5 and set the safety valve 75 to a safe pressure. Valve 82 is then opened to introduce inert gas into pressure vessel 2, followed by valve 32. When the reactive gas is introduced by opening the valve 38, the switching valve 45 is operated to replace the reactive gas with an inert gas. Once the appropriate experimentally obtained concentration is reached, valves 32, 37, 82 and switching valve 45 are closed. Next, the pressure inside the pressure vessel 2 is controlled by setting another safety valve provided in the box of the switching valve 45 (this safety valve is set to a lower pressure than the safety valve 75).

Once the above preparations are completed, the control panel 20 is operated to start machining. In this embodiment, the workpiece 1 is rotated, but the conduit 6 side may also be rotated. Once the processing is complete, use an inert gas to exhaust the reactive gas with the exhaust valve 7.
After expelling from 0, pull out the workpiece.

2(a) and 2(b) show other embodiments of the present invention, in which (a) is a cross-sectional view of the workpiece 1, and (b) is a cross-sectional view of its side surface. In the figure (a), reference numeral 6 indicates a pipe line through which the reactive gas 4 is guided and ejected through nozzles 9 that are connected in series, and reference numeral 5 indicates a laser beam that traverses the reactive gas 4 in the direction of the pipe line 3. 6 is the rotation direction of the workpiece when the pipe line 3 and the laser beam 5 are fixed, 7.8 is the moving direction of the pipe lines 3a and 3b when the workpiece 1 is fixed, and 4a, 4b
05 m indicates the ejection direction of the reactive gas at each position in the pipes, and '5b also indicates the position of the optical path of the laser beam in the pipes 3a and 3b. 0 is their center of rotation.

Figure 6 (&) # (b) shows details of the pressure vessel portion of the embodiment shown in Figure 1, where (a) shows the outside of the workpiece 1; laser beam 5
, a cross-sectional view showing the positional relationship of the reactive gas 4 etc. ejected from the consecutive nozzles 9, and a state in which the pressure vessel 2 is provided outside and isolated from the outside air; (b) is a cross-sectional view thereof; , shows the operation of causing a photochemical vapor deposition reaction while rotating the workpiece 1 in the direction of the arrow 6 to form a film of, for example, Tie or Si on the outer periphery. In the figure 3a
, 3b shows the positions every 90° when the M7JO workpiece 1 is fixed and the pipe 6 is rotated, 4a and 4b show the ejection direction of the reactive gas at each position, and 5a and 5b show the laser beam at each position. It shows the relative positional relationship of the lights.

As can be understood from Figures 6 and 2, the pressure vessel 2 may not be necessary when processing the inner surface of a pipe, and the pressure vessel 2 is necessary when processing the outer surface, except for partial processing. be.

FIGS. 4(a) and 4(b) show still another embodiment of the present invention, and FIG. 4(a) shows a method in which the inside of the workpiece 1 is coated with a focus near the inner wall of the tube using a mirror 10. Since this is connected, when the reactive gas 4 is ejected from the tip of the conduit 3a which can be applied to this part, a photochemical vapor phase deposition reaction occurs and coating waste 11 is formed. Now the workpiece 1, the reflector 10 and the conduit 6
If the & is moved from side to side while rotating relatively, coating debris can be formed over the entire inner surface of the workpiece 1. Of course, by applying this method, it is also possible to draw any pattern on a portion of the inner surface of the tube. Also, in this figure, the laser beam is reflected at right angles by the reflecting mirror 10, but in order to prevent the re-reflected light from backlighting, it is better to project the laser beam at an angle to the workpiece. O Although the configuration and operation of the apparatus according to the present invention have been described above, an example of the conditions for the photochemical vapor deposition reaction in the above embodiments will be shown below.

(a) Reactive gas component Ti0t4+ 02H4(
b) Gas pressure 20 Torr (c) Laser light 002 laser (wavelength 105 μm)
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L bell (1) Laser output 1000 W (F) Coating surface Pipe inner surface (G) Pipe material and dimensions SUS 304.150φ
x 3000X 10 t [tm] (@Pre-vacuum degree I
) was obtained. The reaction formula is Ti0t4+02H4
) TiO+ 41101・・・・・・・・・・・・
1].

The adhesion of the film thus formed to the base material and the adhesion of the film were investigated. The adhesion force exceeded 7F41/-, and the presence or absence of pores in the film was examined by optical microscopy, but there were none, and it was determined that a good film would be formed.@Further reaction The reaction gas is 5iH4 (gas pressure 10 Torr), other conditions are the same as the reaction of equation [1], and SiH4)S1→2H2...between songs...between songs...between songs (
2) When a reaction was caused by thermal decomposition, the film thickness was 100 μm, the adhesion of the film was 7 Kff/- or more, and no pores were observed in the film. ] As explained above, this invention wraps the surface of the workpiece with a reactive gas and emits a laser beam near the surface to apply pressure to cause a photochemical vapor deposition reaction. It has excellent heat resistance, corrosion resistance, abrasion resistance, and strength, and has the effect of efficiently producing a surface with less thermal distortion compared to lining surfaces made by plasma spraying or arc welding.

[Brief explanation of drawings]

Figures 1 (a) and (b) are conceptual diagrams showing one embodiment of the present invention, Figures 2 (,) and (b) are sectional views showing other embodiments of the invention, and Figure 6 (a). ) Bivalent) is a detailed cross-sectional view of the pressure vessel portion of the embodiment shown in FIG. 1, and the fourth screen is a cross-sectional view showing still another embodiment of the present invention. In the figure, 1 is a workpiece, 2 is a pressure vessel, 6 is a pipe line,
4 is a reactive gas, 5 is a laser beam, 6,7°8 is a rotation direction, 20 is a control panel, 25 is a laser oscillator, 30 is a cylinder (
Ti0t4 etc.), 65 is a cylinder (02H4 etc.), 4
0 is a vacuum pump, 45 is a switching valve, 50 is a radius adjuster, 5
5 is a stand, 60Fi drive means, 65 is an opening/closing lid, 70 is an exhaust valve, 75Fi safety valve, and 80 is an inert gas. Agent Patent Attorney Masaru Sato 2nd 3rd year (b) Figure (b)

Claims (1)

[Claims] A coating device that forms a coating layer on one or both of the inner and outer surfaces of a metal tube by a photochemical vapor deposition reaction, which includes a sealing means for placing the surface of the metal tube in a sealed space, and a vacuum pump for evacuating the sealed space. a gas introducing means comprising one or more nozzles for introducing a reactive gas into a space sealed by the vacuum evacuation means, and irradiating the reactive gas introduced into the sealed space by the gas introducing means with a laser beam. A coating device for the inner and outer surfaces of a tube, comprising: a laser beam irradiation means for causing a photochemical vapor deposition reaction; and a driving means for relatively moving a nozzle of the gas introducing means and a metal tube.