JPH03236457A - Surface coating method for wire rod, bar stock, or tube stock made of al or al alloy - Google Patents

Abstract

PURPOSE:To obtaining a coating layer having superior adhesive strength with high productivity by passing an Al bar stock, or tube stock through a peeling die and immediately though a molten coating metal. CONSTITUTION:A wire rod, bar stock, or tube stock 1 made of A, (alloy) is fed by means of feed rolls 2, and a skin layer is removed by means of a peeling die 4 provided to the side face of an immersion tank 3. Subsequently, the above stock 1 is immediately introduced into a molten metal 5 of a coating material having a melting point lower than that of Al, by which the molten metal 5 is allowed to adhere to the cleaned surface from which surface soil and oxide are removed and forms a surface coating layer. A tube 1 on which the coating layer is formed is drawn through a seal 6 out of the immersion tank 3. By this method, the sound coating layer of a coating metal or alloy having a melting point lower than Al, etc., can be formed on the surface of the bar stock, or tube stock 1 made of Al, etc., with high productivity.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for coating the surface of Al or Al alloy wire rods and tubes, and particularly for forming a stable coating layer with good adhesion and little variation with high productivity. It is something that can be done.

[Problems to be solved by conventional technology and invention] Conventional A
In order to improve the mechanical and chemical properties of l or Al alloys (hereinafter referred to as Al etc.), or as a base for joining such as brazing, metals or alloys with a lower melting point than Al etc. are applied to the surface of Al etc. It is industrially practiced to coat with

A method of immersing Al or the like in molten metal or alloy is known as one of these coating methods. In this immersion method, it is desirable to sufficiently remove oxides on the surface of the material such as Al before immersion, and then immerse the material immediately, which poses a big technical problem. Although the use of flux is also effective, it requires cleaning after coating, resulting in a problem of low productivity.

[Means to solve the problem]

In view of this, as a result of various studies, the present invention has developed a method for coating the surface of a wire rod or tube material such as Al, which can form a stable coating layer with good adhesion and little variation with good productivity.

That is, the present invention provides a method for forming a coating layer of the coating metal or alloy on the surface of the wire rod tube material by passing the wire rod tube material such as Al into a molten metal of a coating metal or alloy having a lower melting point than that of the wire rod tube material. This method is characterized in that a coating layer of the coating metal or alloy is formed on the surface of the wire rod or tube material by passing it through a peeling die immediately before passing it into the molten metal or alloy.

[For production]

The advantage of the present invention is that the surface oxide is removed immediately before immersion in the molten metal, and the coating material comes into contact with the molten metal immediately after removal, so there is almost no oxidation between the removal of the surface oxide film and the molten field coating. , a coating layer with good adhesion can be obtained.

The present invention will be explained below using the drawings.

Figure 1 is a side cross-sectional view of a method for removing coating on the surface of a wire rod tube material made of Al, etc. The tube (1) made of Al, etc. is fed by a feed roll (2), and is installed on the side of a dipping tank (3). The skin layer is removed by a peeling die (4) and immediately introduced into the molten metal of the surface coating (5). The molten metal (5) immediately adheres to the tube (1), which has a clean surface by removing dirt and oxides by peeling, to form a surface coating.

The tube (1) with the surface coating layer is drawn out of the dipping layer (3) through the seal (6). The tray (7) is for catching the molten metal leaking from the seal (6), the roll (8) is for pulling out the tube (1), and the receiver (9) is for catching the peeling waste. It is for discharging.

When the tube (1) is moved laterally in this manner, it does not come into contact with the surface of the molten metal during withdrawal, which is advantageous when stains such as flux are averse or when the surface is not cleaned after being coated.

Figure 2 is a side sectional view of the method of introducing the tube from the bottom of the dipping tank and taking it out from the surface of the molten metal. (2), the skin layer is removed by a peeling die (4) provided at the bottom of the dipping tank (3), and immediately introduced into the molten metal (5) of the coating material.

The molten metal (5) immediately adheres to the surface of the tube (11), whose surface has been cleaned by peeling, and the tube (1), on which the surface coating layer has been formed, is placed above the molten metal (5). The guide roll (8) pulls the tube (1) upward and keeps the tube (1) straight.
) is for discharging peeling waste.

When inserting the pipe (1) into the soaking tank (3) from the bottom,
Not only does the thickness of the surface coating layer become uniform, but also the thickness of the coating layer can be controlled by heating the tube (11) in a furnace or flame immediately after being taken out from the molten metal (5).

In all of the above cases, the cross-sectional shape of the tube is circular, but the cross-sectional shape of the tube is not necessarily limited to a circular shape as long as a peeling die can be manufactured and a peeling operation can be performed. For example, a good surface coating layer can be obtained on a flat rod or a flat tube with a semicircular end as well as on a tube with a circular cross section.

Figure 3 is a side sectional view of a method for coating wire rods such as Al.
The wire (1') made of Al, etc. is heated in a preheating furnace (10), the surface layer is removed by a peeling die (4) installed at the bottom of the dipping tank (3), and the wire is immediately poured into the molten metal (5) of the surface coating material. The line (1'
), the molten metal (5) immediately adheres thereto to form a surface coating layer. The reflow oven (11) heats the surface of the wire (1') to melt the surface coating material and smooth the surface, while at the same time controlling the thickness of the coating layer. The receiver (9) is for discharging peeling waste, and the feed roll (2) and guide roll (8) apply the tension necessary for peeling the wire (1') to the wire (1').
') and to pull the line (1') upward while keeping it straight.

As a surface metal or alloy with a melting point lower than that of Al etc., pure Z
n, Zn alloy, pure n, Sn alloy are mainly used, and Zn
Al, Ag, Cu, Ni.

Good results were also shown for coating materials with relatively high melting points to which elements such as Si were added, with particularly little variation in mechanical strength. If the melting temperature of the coating metal or alloy is high, it is recommended to prevent oxidation of the molten metal surface. Flux is floated to prevent oxidation on the surface of the molten metal. Both chloride-based and fluoride-based fluxes are effective. When flux is used, cleaning is generally required after coating, but depending on the type of flux, cleaning may be omitted. A method of covering with an inert gas such as nitrogen or argon is also effective. Also, if the temperature of the molten metal is high, leakage from the seal will increase, so it is necessary to take measures to prevent it from adhering to wire rods and tube materials such as Al.

The composition of Al, etc. in the present invention is essentially irrelevant, and if Al or an alloy mainly composed of Al is used,
A good surface coating can be formed with 0 series, 200G series, 3G (1(l series, 4QGQ series, 5000 series, 6000 series, and 7000 series).

Although the temperature control of the immersion tank was not specifically explained,
Since the temperature of the bath affects the thickness of the coating material, accurate automatic control is desirable. Furthermore, if necessary, it is effective to provide a local heating device for Al or the like during coating or after coating, and local heating is particularly effective when it is desired to reduce the thickness of the coating layer.

〔Example〕

Examples of the present invention will be described below.

In the example, using the apparatus shown in FIG. 1, 35%3n-64%Zn-1
Al alloy 10 with an outer diameter of 22 mm and an inner diameter of 18 mm is passed through a peeling die into a 390°C molten metal made of a Cu alloy.
The tube No. 02 was immersed, passed through the molten metal at a speed of 20 m#nin, and pulled out from the molten metal.

The pipe material pulled out from the molten metal in this way has a thickness of 30 μm.
Healthy 35%5n-64%Zn with no pinholes etc.
A -1% Cu alloy coating layer was obtained.

Example 2 Using the apparatus shown in Fig. 3, an Al alloy 1002 wire with a wire diameter of 1 mm was passed through a peeling die into a molten metal of 15% Al-85% Zn alloy at 450°C,
It was passed through at a speed of m/min and drawn out from the molten metal.

In this case, since the temperature of the molten metal was high, the surface of the molten metal was covered with nitrogen to prevent oxidation of the molten metal surface.

The wire rod pulled out of the molten metal in this way has a thickness of 20 mm.
Healthy 15%A [-85%Z with no μm pinholes etc.
A coating layer of n-alloy was obtained.

〔Effect of the invention〕

As described above, according to the present invention, a healthy coating layer of a coating metal or alloy having a melting point lower than that of Al etc. can be formed on the surface of a wire rod tube material such as Al with high productivity, and mechanical and chemical It has remarkable industrial effects as a treatment for property improvement and bonding.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of the h method for coating the surface of a tube bar according to the present invention, and FIG. 2 is a side sectional view showing another example of the method for coating the surface of a tube bar according to the present invention. 3 is a side sectional view showing an example of a method of coating the surface of a wire according to the present invention. ■, Pipe 1', Wire 2, Feed roll 3, Dipping tank 4, Peeling die 5, Molten metal 6, Seal 7, Receiver is plate roll Receiver is preheating furnace Reflow oven 2 Fig. 1 Fig. 2

Claims (1)

[Claims] In this method, an Al or Al alloy wire rod tube material is passed through a molten metal of a coated metal or alloy having a lower melting point to form a coating layer of the coated metal or alloy on the surface of the wire rod tube material. A method for coating the surface of an Al or Al alloy wire rod or tube material, which comprises cleaning the surface by passing it through a peeling die immediately before passing it through a molten alloy, and immediately forming a coating layer of a coating metal or alloy.