WO2008144989A1

WO2008144989A1 - Electrophoretic steel pipe and its electrophoretic finishing method and the whole set equipment

Info

Publication number: WO2008144989A1
Application number: PCT/CN2007/070945
Authority: WO
Inventors: Zailiang Li
Original assignee: Wuhan Lisheng Super Filtration Science And Technology Ltd.
Priority date: 2007-05-25
Filing date: 2007-10-24
Publication date: 2008-12-04
Also published as: CN101122358A

Abstract

A steel pipe and its production method and equipment, in particularly, a electrophoretic steel pipe and its electrophoretic finishing method and equipment includes a steel pipe having electrophoretic coating on its inner wall and outer wall; the method includes a cathode and an anode electrophoretic technique, in which, when the cathode electrophoretic technique is used, an accessorial anode is put in the deep hole of the steel pipe; when the anode electrophoretic technique is used, an accessorial cathode is put in the deep hole of the steel pipe. The invention solves the electrophoretic process problem on the inner wall and the outer wall of the steel pipe, so the anticorrosion of the inner and outer wall of part is solved. The invention can be used widely in chemical engineering, petroleum and natural gas industry, and it has excellent anticorrosion function.

Description

Electrophoretic coating method and complete equipment for electrophoresis steel tube and electrophoresis steel tube

The invention relates to a steel pipe and a production method and equipment thereof, in particular to an electrophoretic coating technology and a complete set of equipment for electrophoresis steel pipe and electrophoresis steel pipe.

Background technique

Pipeline transportation is one of the five major modes of transportation today, and it has become the main transportation tool for oil and gas. At present, the total length of the world's oil and gas pipelines is about 2 million km. The total length of our long-distance pipelines is about 20,000 km. The national key project "West-to-East Gas Emission" project has a total length of 4167km, and its main pipeline investment is 38.4 billion yuan. In addition, the city's pipe network investment will exceed 100 billion yuan. At present, pipes for pipeline transportation generally use metal steel pipes and plastic rubber pipes. The metal steel pipes have the advantages of high strength and are suitable for long-distance transportation, but they have the disadvantage of poor corrosion resistance; plastic rubber pipes have the advantages of high corrosion resistance, but It has the disadvantage of low strength and is only suitable for short distance transport. Therefore, solving the corrosion protection problem of steel pipes is an important issue faced by those skilled in the art. Nowadays, galvanized steel pipes are generally used for galvanized steel pipes or anti-corrosion coatings are applied to ordinary steel pipes for anti-corrosion purposes. The disadvantage of this method is that the galvanized layer of the galvanized steel pipe is susceptible to oxidative corrosion and spalling, and can cause secondary pollution, and the country is gradually banned from use. Ordinary steel pipes coated with anti-corrosion coatings also have the defects that the anti-corrosion layer is easily aged and peeled off, resulting in a short service life.

Since the development of the electrophoretic coating technology in the 1960s and its industrial application, it has excellent high corrosion resistance, high throughput, high coulombic efficiency, insoluble coating, stable bath and high automation. Advantages, and therefore widely used in industries such as automobiles, motorcycles, household appliances, instruments, military, building materials, decoration five, light industry and daily use, It has gradually replaced conventional surface coating technology and has become one of the most important coating techniques in the world today.

At present, the electrophoretic coating technology mainly adopts an ordinary electrophoresis treatment method, and the electrophoresis process generally has a simple workpiece structure and a relatively easy to paint workpiece, but due to the influence of the electrophoretic coating of the electrophoretic coating and the influence of the conductive efficiency, the tubular metal is applied. The internal anti-corrosion treatment of pieces (such as iron pipes, galvanized pipes, steel pipes and other metal conductors) and the corrosion treatment of specially treated non-metallic conductive members cannot be treated by conventional electrophoresis techniques, and other treatment methods are also The anti-corrosion problem of the inner and outer walls of such components cannot be better solved.

Summary of the invention

The object of the present invention is to provide an electrophoretic coating technology and a complete set of equipment for electrophoresis steel pipe and electrophoresis steel pipe, which solves the electrophoresis problem of the inner and outer walls of the metal steel pipe, thereby completely solving the inside of the metal steel pipe. , the anti-corrosion problem of the outer wall.

The object of the present invention is achieved by the following technical solutions: It comprises a steel pipe, characterized in that: an electrophoretic coating is electrophoresed on both the inner and outer walls of the steel pipe.

The steel pipe is an iron pipe, a galvanized steel pipe or a plastic galvanized steel pipe; the electrophoretic coating comprises a thermosetting coating or a photosensitive coating; and the electrophoretic coating comprises one of a dye, a pigment, a filler or an auxiliary agent. Or electrophoretic coating comprising colorless transparent, matte colorless, black, gray, white, red, yellow, green, blue, and flash or pearlescent electrophoretic coating; The electrophoretic coating is specifically one or more of a polybutadiene resin, a phenol resin, an epoxy resin, an acrylic resin or a polyurethane.

The electrophoretic coating technology method of the invention comprises two methods, a cathodic electrophoresis process and an anodic electrophoresis process, wherein: in the cathodic electrophoresis process, a supplement is placed inside the deep hole of the steel pipe Auxiliary anode; In the anodic electrophoresis process, an auxiliary cathode is placed inside the deep hole of the steel pipe. The steel pipe coated by the method of the invention is an iron pipe, a galvanized pipe or a plastic pipe; the electrophoretic coating used is one or more of polybutadiene resin, phenolic resin, epoxy resin, acrylic resin or polyurethane. The electrophoretic coating used contains an electrophoretic coating with added fillers or auxiliaries. The electrophoretic coating comprises colorless transparent, matte colorless, black, gray, white, red, yellow, green, blue color, and flash color, pearl color and electrophoretic coating with dye and pigment added; The electrophoretic coating comprises a thermosetting coating or a photosensitive coating; the auxiliary anode material is an electrically conductive conductor member.

In the cathodic electrophoresis process: the steel pipe is the electrophoresis element, the negative electrode (-) of the power supply, the anode

Connect C to the positive terminal of the power supply ( + ) and insert an auxiliary anode (B) inside the steel pipe. Auxiliary The anode material is a metal or non-metal metallized conductor that can pass current, and the auxiliary anode can be close to the inner wall of the pipe, but cannot be in direct contact with the steel pipe. Non-conducting non-conducting objects such as plastic, rubber, wood and other non-conducting materials are required to support or block the auxiliary anode from colliding with and contacting the workpiece, and the non-conducting body has regular or irregular holes. Conducive to the electrophoretic coating into the inside of the steel pipe The connection between the anode wire of the power source and the auxiliary anode can be connected at one end or at both ends.

In the anodic electrophoresis process: the steel pipe is an electrophoresis element, connected to the positive electrode (+) of the electrophoresis source, the cathode C is connected to the negative electrode (-) of the power source, and an auxiliary cathode (B) is placed inside the steel pipe. The auxiliary cathode material is a metal or non-metal metallized conductor that can pass current. The auxiliary cathode and the inner wall of the pipe can be far apart, but cannot be in direct contact with the steel pipe. Non-conducting non-conducting objects such as plastic, rubber, wood and other non-conducting materials are required to support or block the auxiliary cathode from colliding with and contacting the workpiece, while the non-conducting body is regular or not Regular holes help the electrophoretic coating to enter the interior of the workpiece. The connection mode of the power cathode wire and the auxiliary cathode may be connected at one end or may be connected at both ends.

The invention can be combined into a brand-new complete equipment by the existing equipment, which is sequentially assembled by the following equipment: a steel pipe feeding machine, a degreasing machine, a water washing machine, a surface adjusting machine, a phosphating machine, a water washing machine, an electrophoresis machine, and a spraying machine. Shower machine, a washing machine, a baking machine, a cooling machine. This complete set of equipment can produce single and multiple electrophoresis steel tubes.

The process flow of the invention is as follows: a steel pipe, a degreasing, a water washing, a table, a phosphating, a water washing, an electrophoresis, a spray, a water washing, a baking, a forced cooling, and a finished product packaging.

The invention has the advantages of simple structure, low manufacturing cost and wide application range, and the technical method of the invention can solve the electrophoresis treatment problem of the inner and outer walls of the steel pipe, thereby completely solving the anti-corrosion problem of the inner and outer walls of the workpiece. The electrophoresis steel pipe of the invention can be widely applied to industries such as chemical industry, petroleum and natural gas, and has excellent corrosion resistance.

DRAWINGS

Figure 1 is a schematic view of a steel tube during cathodic electrophoresis

Figure 2 is a schematic view of the steel tube during the anodic electrophoresis process.

Figure 3 is a combination diagram of the complete equipment of the present invention

detailed description

Example 1

As shown in Fig. 1, the specific steps of the present invention in the cathodic electrophoresis process are as follows: The steel pipe A is an electrophoresis member, which is a cathode system, and is connected to a negative electrode (-) of a power source. Auxiliary anode B is connected to the positive pole of the power supply ( + ). Anode C is connected to the positive terminal of the power supply ( + ).

1. Connect the workpiece to the negative (-) of the power supply. 2. Place the auxiliary anode inside the workpiece.

3. Connect the auxiliary anode to the positive terminal ( + ) of the power supply and connect the anode of the electrophoresis tank to the positive terminal ( + ) of the power supply.

4. Place the electrophoresis workpiece into the electrophoretic coating solution. The electrophoretic coating may be a polybutadiene resin, a phenol resin, an epoxy resin, an acrylic resin or a polyurethane.

5. Turn on the power. There are several methods: (1) Partial electrophoresis can be used to connect the anode and the auxiliary anode with a diverter switch. A. First electrophoresis the inside of the workpiece, connect the diverter switch to the auxiliary anode, and then electrophorese the inside of the workpiece. After that, the power switch will be switched to the anode and the outside of the workpiece will be electrophoresed. B. Electrophoresis of the outside of the workpiece, connecting the diverter switch to the anode, and then electrophoreting the outside of the workpiece. After that, switch the power switch to the auxiliary anode and electrophorese the inside of the workpiece. (2) Simultaneous electrophoresis can also be used to turn on the power and simultaneously electrophorese the inside and outside of the workpiece. (3) It is also possible to use two electrophoresis power sources to connect the auxiliary anode and the workpiece, and the other to connect the anode and the workpiece, and both of them simultaneously start the inside of the electrophoretic workpiece and the outside of the workpiece.

The thickness of the electrophoretic paint film can be guaranteed by controlling the voltage and time and other conditions.

As shown in FIG. 3, the steps of the coating technique method of the present invention are as follows:

1. The steel pipe enters the feeding machine and starts to load the production line on the fixture for production.

2. The steel pipe first enters the degreaser equipment and is degreased and degreased to make the surface clean.

3. The steel pipe enters the washing machine and is washed with water. The water washing can be washed one or more times to wash off the liquid and impurities from the previous process to clean the surface of the workpiece.

4. The steel pipe enters the surface conditioner to adjust the surface, which is beneficial to the phosphating film formation.

5. The steel pipe enters the phosphating machine and is phosphatized to obtain different phosphate coating layers on the surface, which is beneficial to the performance of the electrophoretic paint film. 6. The steel pipe enters the washing machine and is washed with water. The washing can pass one or more passes. Wash off the liquid and impurities from the previous process to clean the surface of the workpiece.

7. The steel pipe enters the electrophoresis machine and is subjected to electrophoresis treatment, and the inner and outer walls of the steel pipe are electrophoresed.

8. The electrophoresis steel pipe enters the sprayer equipment and is sprayed. The medium used for spraying can be ultrafiltration water or pure water. Ultrafiltration is the water and solvent separated in the electrophoresis tank, which is good for cleaning. The cleaning solution is returned to the electrophoresis tank.

9. The electrophoresis steel pipe enters the washing machine and is washed with water. Wash off the liquid and impurities from the previous process to clean the surface of the workpiece.

10. The electrophoresis steel tube enters the baking machine and is baked and cured. The baking machine equipment can be a heat curing baking device (such as electric heating, fuel heating, etc.) or a heat curing device (such as ultraviolet curing).

11. The electrophoresis steel tube enters the forced cooling equipment to be forced to cool, and it is quickly dried to make the workpiece easy to pack.

12. The electrophoresis steel pipe enters the cutting machine and is packed in the blank.

Example 2

As shown in Fig. 2, the specific steps of the present invention in the anodic electrophoresis process are as follows: The steel tube (A) is an anode system for the electrophoresis member, and is connected to the positive electrode (+) of the power source. The auxiliary cathode B is connected to the negative pole of the power supply (-). The cathode C is connected to the negative pole of the power supply (-).

1. Connect the workpiece to the positive terminal of the power supply ( + ).

2. Place the auxiliary cathode inside the workpiece.

3. Connect the auxiliary cathode to the negative terminal (-) of the power supply, and connect the cathode of the electrophoresis tank to the negative terminal (-) of the power supply. 4. Place the electrophoresis workpiece into the electrophoretic coating solution. The electrophoretic coating may be a polybutadiene resin, a phenol resin, an epoxy resin, an acrylic resin or a polyurethane.

5. Turn on the power. There are several methods: (1) Partial electrophoresis can be used to connect the cathode and the auxiliary cathode with a diverter switch. A. First electrophoresis the inside of the workpiece, connect the diverter switch to the auxiliary cathode, and then electrophorese the inside of the workpiece. After that, the power switch will be switched to the cathode and the outside of the workpiece will be electrophoresed. B. Electrophoresis of the outside of the workpiece, connecting the diverter switch to the anode, and then electrophoreting the outside of the workpiece. After that, switch the power switch to the auxiliary anode and electrophorese the inside of the workpiece. (2) Simultaneous electrophoresis can also be used to turn on the power and simultaneously electrophorese the inside and outside of the workpiece. (3) It is also possible to use two electrophoresis power sources to connect the auxiliary cathode and the workpiece, and the other to connect the cathode and the workpiece, and both of them simultaneously start the inside of the electrophoretic workpiece and the outside of the workpiece.

The specific coating technique method steps are the same as in the first embodiment.

Example 3

As shown in Fig. 1, the specific steps of the present invention in the cathodic electrophoresis process are as follows: The plastic galvanized steel pipe A is an electrophoresis member, which is a cathode system and is connected to a negative electrode (-) of a power source. Auxiliary anode B is connected to the positive pole of the power supply ( + ). Anode C is connected to the positive terminal of the power supply ( + ).

1. Connect the galvanized steel pipe to the negative pole of the power supply (-).

2. Place the auxiliary anode inside the workpiece.

4. Place the electrophoresis workpiece into the electrophoretic coating solution. The electrophoretic coating may be a polybutadiene resin, a phenol resin, an epoxy resin, an acrylic resin or a polyurethane. 5. Turn on the power. There are a variety of methods: (1) Partial electrophoresis can be used to connect the anode and the auxiliary anode with a diverter switch. A. First electrophoretic galvanized steel pipe inside, connect the switch to the auxiliary anode, and then electrophorese the inside of the workpiece. After that, the power switch will be switched to the anode and the outside of the workpiece will be electrophoresed. B. Electrophoresis the outside of the workpiece, connect the diverter switch to the anode, and then electrophorese the outside of the workpiece. After that, switch the power switch to the auxiliary anode and electrophorese the inside of the workpiece. (2) Simultaneous electrophoresis can also be used to turn on the power supply and simultaneously electrophoretic galvanized steel pipe inside and outside. (3) It is also possible to use two electrophoresis power sources to connect the auxiliary anode and the workpiece at the same time, and the other to connect the anode and the workpiece, and both of them simultaneously start the inside of the electrophoretic workpiece and the outside of the workpiece.

As shown in Fig. 3, the coating technique method steps of the present invention are the same as in the first embodiment.

Claims

Claim

An electrophoresis steel pipe comprising a steel pipe, characterized in that: an electrophoretic coating is electrophoresed on both the inner wall and the outer wall of the steel pipe.

2. The electrophoresis steel tube according to claim 1, wherein the electrophoretic coating comprises a thermosetting coating or a photosensitive coating.

The electrophoresis steel pipe according to claim 1 or 2, wherein the electrophoretic coating material is added with one or more of a dye, a pigment, a filler or an auxiliary agent.

4. The electrophoresis steel tube according to claim 3, wherein the electrophoretic coating comprises colorless transparent, matte colorless, black, gray, white, red, yellow, green, blue, and flash or pearl. Color electrophoretic coating.

The electrophoresis steel pipe according to claim 3, wherein the electrophoretic coating material is one or more of a polybutadiene resin, a phenol resin, an epoxy resin, an acrylic resin or a polyurethane resin.

6. An electrophoretic coating technique for an electrophoretic steel tube, in which an auxiliary anode is placed inside a deep hole of a steel pipe during a cathodic electrophoresis process.

7. The electrophoretic coating technique of an electrophoresis steel tube according to claim 6, wherein the auxiliary anode material is an electrically conductive conductor member.

8. An electrophoretic coating technique for an electrophoresis steel pipe, which is an auxiliary cathode placed inside a deep hole of a steel pipe during an anodic electrophoresis process.

9. The electrophoretic coating technique of an electrophoresis steel tube according to claim 14, wherein said auxiliary cathode material is an electrically conductive conductor member.

10. A coating device for an electrophoresis steel pipe, which is sequentially assembled by the following equipment: steel

Electrophoresis