JPH0653898B2 - Method for manufacturing heat exchanger fin material with high strength - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a heat exchanger fin material which has high room temperature and high temperature strength and can be thinned.

[Conventional technology]

In general, pure Al and Al alloys are lightweight, have excellent thermal conductivity, and have excellent corrosion resistance, and are therefore widely used for manufacturing heat exchangers such as automobile radiators.

This heat exchanger has, for example, a tube material composed of an Al-Mn-based alloy as a core material and a brazing sheet made by clad with a brazing material of an Al-Si-based alloy on one surface of the core material, pure Al or pure Al or Produced by combining with a fin material of an Al-Mn-based alloy, and brazing this combination in a vacuum or in an inert gas without flux, or in a low pressure atmosphere with flux. There is.

[Problems to be solved by the invention]

Therefore, the heat exchanger fin material is required to have sufficient droop resistance, that is, high-temperature strength, so as not to be deformed by heating above the melting temperature of the brazing material during brazing. Since the fin material of the system alloy does not have a sufficiently high temperature and altitude, the predetermined strength is secured by increasing the plate thickness.

On the other hand, in recent years, there has been a strong demand for energy saving and weight reduction of heat exchangers, and there is an urgent need to reduce the thickness of fin materials. However, as mentioned above, existing fin materials are insufficient in strength. Therefore, the current situation is that there is a limit to thinning.

[Means for solving problems]

Therefore, the inventors of the present invention have conducted research to develop a heat-exchanger fin material having a high strength capable of reducing the thickness from the above viewpoint, and as a result, for example, pure Al or Al-Mn.
Pure Al that has been used as a conventional fin material such as alloys
And a molten aluminum alloy is sprayed from the slit formed in the bottom of the crucible in which it is accommodated onto the surface of the cooling rotary roll positioned immediately below it, and is rapidly quenched and solidified to have a thickness of 0.03 to 0.2. When a heat exchanger fin material of mm is formed, the resulting fin material has a high-temperature and high-temperature strength because it has a fine structure in which crystallized substances and impurities are finely dispersed. It is possible to simply blow the molten metal onto the surface of the cooling rotary roll without the need for a series of steps such as ingot casting, forging, hot rolling, cold rolling, and intermediate annealing in the conventional fin material manufacturing. It can be manufactured, and in this case, the plate thickness can be adjusted freely,
We obtained the research results that it is possible to manufacture thin-walled products.

The present invention has been made based on the above-mentioned research results, and directly melts pure Al or Al alloy by blowing it onto the surface of a cooling rotary roll to solidify it by ultra-rapid cooling. It is characterized by the method of forming the heat exchanger fin material.

In the fin material manufactured by the method of the present invention,
The thickness is limited to 0.03 to 0.2 mm because the thickness is 0.
Even if it is less than 03 mm, it can be used as a fin material, but it is extremely difficult to manufacture a continuous and perfect fin material with a thickness of less than 0.03 mm by the current technology, while the thickness of 0.2 mm is required. This is based on the reason that, if it exceeds, not only the thickness along the length direction becomes extremely uneven in manufacturing, but also it is not desirable in terms of weight reduction.

〔Example〕

Next, the method of the present invention will be specifically described by way of Examples.

In the melting crucible, melts each having the component composition shown in Table 1 were prepared. After that, the molten metal was sprayed onto the surface of a water-cooled copper roll having a diameter of 300 mm, which was located directly under the slit and rotated at 2000 rpm, through a slit having a size of 0.5 mm × 15 mm provided at the bottom of the crucible. In this case, the inner pressure of the crucible was adjusted to 0.5 to 1.5 atm by Ar gas, and the ratio of the molten metal discharged from the slit was controlled, and the width having three kinds of thickness shown in Table 1 was 16 mm. Each of the methods 1 to 9 of the present invention was carried out by forming a fin material.

In addition, for the purpose of comparison, using a molten metal having the same composition of components, casting this in a water-cooled mold to form an ingot with dimensions of 30 mm × 150 mm × 300 mm, and heat the ingot under normal conditions. Conventional methods 1 to 9 were carried out by producing H12 tempered fin material having the same dimensions by repeatedly performing cold rolling and cold rolling and intermediate annealing.

Then, with respect to the fin material obtained as a result, the tensile strength was measured for the purpose of evaluating the room temperature strength, and the sag resistance test was performed for the purpose of evaluating the high temperature strength. In the droop resistance test, a test piece with a size of width: 16 mm × length: 130 mm was used, and the heat exchange was performed while the part 30 mm from one end in the length direction was held horizontally. The conditions equivalent to the vacuum brazing used in the manufacture of the container, that is, about 10 ^-4 torr
In a vacuum, the temperature was maintained at 620 ° C. for 10 minutes, and the hanging height of the tip of the sample was measured. The first of these measurement results
Shown in the table.

〔The invention's effect〕

From the results shown in Table 1, the fin materials manufactured by the methods 1 to 9 of the present invention all have significantly excellent room temperature and high temperature strength as compared with the fin materials manufactured by the conventional methods 1 to 9. Is clear.

As described above, according to the method of the present invention, a heat exchanger fin material having high room temperature and high temperature strength can be manufactured. Therefore, even if the heat exchanger fin material is put into practical use in a thinned state, the heat exchanger manufacturing can be performed. Since it does not deform during brazing, it exhibits excellent performance for a long time in a state where it is possible to reduce the weight, and it is directly manufactured by super-quenching and solidifying the molten metal. Industrially useful effects such as energy saving can be achieved as compared with the production of fin materials.

Claims (1)

[Claims] 1. A heat exchanger fin material having a thickness of 0.03 to 0.2 mm is directly formed by spraying a molten metal of pure Al or an Al alloy onto the surface of a cooling rotary roll to solidify it by rapid quenching. Manufacturing method of heat exchanger fin material having high strength.