JP2907353B2 - Method of manufacturing high strength aluminum alloy sacrificial fin material for low temperature brazing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high strength aluminum alloy sacrificial fin material.
The present invention relates to a high-strength sacrificial fin material for low-temperature brazing for brazing at a temperature of 500 ° C. or less, and is particularly used as a fin of a radiator, a heater, a condenser, etc. of a heat exchanger for an automobile.

[0002]

2. Description of the Related Art Al and Al alloys are used in many heat exchangers for automobiles and are manufactured by a brazing method. Usually, Al-Si-based brazing material is used for brazing, so brazing is performed at a high temperature of about 600 ° C. In a heat exchanger such as a radiator, for example, as shown in FIG. 1, thin fins (2) formed into a corrugated shape are integrally formed between a plurality of flat tubes (1), and both ends of the flat tubes (1) are It is open to the space formed by the header (3) and the tank (4), and sends the high-temperature refrigerant from the space on one tank side to the space on the other tank (4) side through the flat tube (1). , Tube (1)
In addition, the refrigerant that has undergone heat exchange at the fins (2) and cooled to a low temperature is circulated again. By the way, in recent years, heat exchangers have been reduced in weight and size, and for that purpose, thinner materials are desired. However, when the thickness of the conventional material is reduced, the strength is insufficient because the thickness of the material is reduced. Therefore, some high-strength alloys have been proposed, but sufficient strength has not been obtained. This is because of the brazing to be heated to around 600 ° C. As a final step of the product, because the mechanism of improving the strength of machining or hardening is not available. Further, when the thickness of the tube material, the tank material, the header material, and the like is reduced , the fin material needs to have a sufficient sacrificial anode effect for the corrosion resistance of the heat exchanger.

[0003]

SUMMARY OF THE INVENTION In view of the foregoing, the present invention has been developed in order to develop a sacrificial fin material having high strength after brazing, which is suitable for brazing at a low brazing temperature instead of the conventional brazing. The present invention was deemed to be able to solve the problem by developing a fin material, and reached the present invention. Here, the brazing at a low brazing temperature is a brazing method developed in recent years due to a growing demand for lowering the brazing temperature due to a reduction in brazing cost. By lowering the temperature, various advantages such as a reduction in the brazing time, a reduction in the amount of heat, a reduction in the cost of the brazing furnace, and an improvement in the durability of the brazing furnace are produced. Currently developed brazing materials that can be brazed at a low temperature include, for example, pure Zn, Zn-0.28 wt% Al, Z
n-Al system, Zn-Cd system, Sn-Zn system, Sn-Pb
System. However, considering the corrosion resistance of the heat exchanger after brazing, a Zn-Al-based brazing material is most effective. That is, the present invention is directed to a method of manufacturing a sacrificial fin material suitable for the low-temperature brazing method at a temperature of 500 ° C. or lower, having excellent strength after brazing and capable of thinning.
The described invention is characterized by exceeding 13.0 wt% Fe and 12.0 wt%
It contained the following, Zn0.3~2.0wt%, In0.0
It contains one or more of 3 to 0.3 wt% and 0.03 to 0.3 wt% of Sn, and has a plate thickness of 10 mm or less from an Al alloy melt composed of the balance of Al and inevitable impurities .
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized in that the sheet is rapidly cooled and cast to a final thickness by rolling . Fe content of more than 3.0 wt% and 12.0 wt% or less , Zn 0.3-2.0 wt%, In 0.03-0.3
wt%, and contain one or more of Sn0.03~0.3wt%, further V, Cr, Mn, Ni, T
0.1 to 5.0 wt% of each of i, Zr, Mo, Co, and W
Alloy containing at least 16 wt% of one or more of the above, and the balance being Al and unavoidable impurities.
A plate with a plate thickness of 10 mm or less is quenched from hot water and rolled.
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized by processing to the final sheet thickness. The invention according to claim 3 is characterized in that Fe exceeds 3.0 wt% and 12.0 wt% or less . 0.3 to 2.0 wt% Zn
%, In 0.03 to 0.3 wt%, and Sn 0.03 to 0.
One or more of 3 wt%, and further 0.1 to 2.5 wt% of Si and 0.1 to 0.5 wt% of Mg
%, Containing one or more of Cu0.1～1.5Wt%, consisting of the remainder Al and unavoidable impurities A
l Rapid casting of a plate with a thickness of 10 mm or less from the molten alloy
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized by processing to a final thickness by rolling.
% Contained the following 12.0wt% exceeded, Zn0.3~
2.0 wt%, In 0.03-0.3 wt%, Sn0.
Containing one or more of 03 to 0.3 wt%, and V, Cr, Mn, Ni, Ti, Zr, Mo, Co,
W contains one or more of 0.1 to 5.0 wt% of each W in a total of 16 wt% or less.
2.5 wt%, Mg 0.1-0.5 wt%, Cu0.
Al alloy melt containing one or two or more of 1 to 1.5 wt%, the balance being Al and unavoidable impurities
A plate with a thickness of 10 mm or less is rapidly quenched and rolled.
This is a method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized by performing processing up to the end plate thickness . In the invention as set forth in claims 1 to 4 , it is more effective to perform a precipitation treatment at 300 ° C. to 450 ° C. before or during the rolling, and set the rolling reduction to the final sheet thickness after the precipitation treatment to 20% or more. is there.

[0004]

First, the alloy composition of the fin material manufactured by the method of the present invention will be described. The first fin material is Fe
Contains more than 3.0 wt% and 12.0 wt% or less ;
0.3-2.0 wt%, In0.03-0.3 wt%,
A sacrificial fin material containing one or more of Sn in an amount of 0.03 to 0.3 wt% and the balance being aluminum. Fe exists as dispersed particles and solid solution Fe in the alloy, and prevents fins from softening due to recrystallization of the fin material during brazing at 500 ° C. or less. That is, the dispersed particles fine and stabilize the sub-crystal grains, and the solute Fe pins the dislocation. By such an action, 50
If brazing heating is performed at 0 ° C. or less, high strength is exhibited thereafter. If the content of Fe is 3.0 wt% or less, the above-mentioned action is insufficient. If the content exceeds 12.0 wt%, the formability of the material is reduced and corrugating as a fin material cannot be performed. Therefore, the content of Fe exceeds 3.0 wt% and
It is determined to be 2.0 wt% or less. Zn, In, and Sn lower the potential of the fin material, impart a sacrificial effect to the fin material, and increase the corrosion resistance of the heat exchanger. The amount is Zn
0.3 wt% or less, In0.03 wt% or less, Sn0.
At less than 03 wt%, the sacrificial effect is not sufficient, and Zn
Beyond 0 wt%, In exceeds 0.3 wt%, Sn
Even if it is added in excess of 0.3% by weight, the effect does not change, and conversely, the moldability as a fin material decreases. Therefore, Zn
0.3-2.0 wt%, In0.03-0.3 wt%,
It is determined to contain one or more of Sn 0.03 to 0.3 wt%. The second invention fin material is a further improvement of the first invention, and it is Fe3.0w.
beyond the t% contained the following 12.0wt%, Zn0.3~
2.0 wt%, In 0.03-0.3 wt%, Sn0.
One, two or more of the above components are contained in an amount of V, Cr, Mn, Ni, Ti, Zr, Mo,
This is a sacrificial fin material containing one or more of Co and W each in an amount of 0.1 to 5.0 wt% so as to be 16 wt% or less in total, and the balance being aluminum. Here, V, Cr, Mn, Ni, Ti, Zr, Mo, C
Both o and W exist as fine intermetallic compound particles, help the function of Fe, and contribute to strength improvement. In any case, if the amount is less than 0.1 wt%, the action is not sufficient, and
Even if it is added in excess of 0% by weight, only coarse particles are generated, and there is no effect in improving the strength, which is wasteful. Therefore, V, C
The addition amount of each of r, Mn, Ni, Ti, Zr, Mo, Co, and W is 0.1 to 5.0 wt%. It is effective to add only one of these elements. When two or more are added, the total is determined to be 16 wt% or less. This is because if the total exceeds 16% by weight, there is no effect on improving the strength, and conversely, the formability is reduced. Third invention has further improved the 1st invention in the second and different mechanisms, 12.0 exceed Fe3.0Wt%
wt% or less , Zn 0.3-2.0 wt%, In
0.03 to 0.3 wt%, Sn 0.03 to 0.3 wt%
And one or more of these, and further containing Si0.
1-2.5 wt%, Mg 0.1-0.5 wt%, Cu
It is a sacrificial fin containing one or more of 0.1 to 1.5 wt% and the balance being aluminum. Here, Si, Mg and Cu mainly exist in a solid solution state in the alloy to improve the strength, and when the cooling rate during brazing is high, the strength is improved by age hardening. In any case, if the amount is less than 0.1 wt%, the action is not sufficient. S
When the amount of i exceeds 2.5 wt%, a coarse intermetallic compound combined with Fe is generated, and the improvement of strength is hindered. If Mg exceeds 0.5 wt%, it reacts with the flux used for brazing, and brazing cannot be performed. Cu
If the content exceeds 1.5 wt%, the potential of the fin becomes noble, the sacrificial effect is reduced, and when used as a heat exchanger, corrosion proceeds from a tube or the like. Therefore, the respective addition amounts are 0.1 to 2.5 wt% of Si and 0.1 to 0.2 wt% of Mg.
It is determined to be 5 wt% and 0.1 to 1.5 wt% of Cu. In addition,
These elements are effective even if only one kind is added or two or more kinds are added. The fourth invention is the first invention in which the second invention
The third and third inventions have both been carried out, and the Fe3.0
wt% to 12.0 wt% or less ;
~ 2.0wt%, In0.03-0.3wt%, Sn
One or more of 0.03 to 0.3 wt%, V, Cr, Mn, Ni, Ti, Zr, Mo, C
one or more of each of 0.1 to 5.0 wt% of o and W are contained so as to be 16 wt% or less in total;
Further, Si to 2.5 wt%, Mg 0.1 to 0.5 wt
%, And 0.1 to 1.5 wt% of Cu.
The role of the additional element of the fin material is the same as described above. The components of the alloy fin of the present invention have been described above. In the fin material of the present invention, if the elements other than the above are each less than 0.1 wt% and less than 1.0 wt% in total, the fin material is cast even if it is contained as an unavoidable impurity. It may be added even if it is added for the purpose of making the structure finer at the time.

Next, a method for producing the alloy fin material of the present invention will be described. First, the first manufacturing method is characterized in that a plate or a thin strip having a thickness of 10 mm or less is quenched and cast from a molten aluminum alloy having a desired composition, and is processed to a final thickness by rolling. It is. Here, the rapid casting is a method such as the Hunter method or the 3C method. By performing quenching, Fe, V, Cr, Mn, Ni, Ti,
Zr, Mo, and W become fine particles, and Fe dissolves in supersaturation, and when brazing at a temperature of 500 ° C. or less,
Prevents fins from softening. Processing of the quenched and cast plate to the thickness of the fin material is performed by rolling. In this case, cold rolling may be usually performed . The second manufacturing method is
In manufacturing the above four types of fin materials, a plate or a thin strip having a thickness of 10 mm or less is rapidly quenched from a molten aluminum alloy having a desired composition, and is rolled to a final thickness of 300 ° C. A production method characterized in that a precipitation treatment is performed at ~ 450 ° C before or during rolling, and a rolling reduction to a final sheet thickness after the precipitation treatment is 20% or more. The precipitation treatment is a treatment for depositing Fe,
When V, Cr, Mn, Ni, Ti, Zr, Mo, Co, and W are added, they have an action of precipitating these. When the precipitation treatment is performed, the above elements are very finely and densely distributed, so that the effect of preventing softening during brazing heating is extremely remarkable. When the temperature of the precipitation treatment is lower than 300 ° C., sufficient precipitation does not occur, and when the temperature exceeds 450 ° C., the precipitation is coarsened and the effect is conversely reduced. Therefore, the temperature of the precipitation treatment is 300 ° C to 4 ° C.
Determine to be 50 ° C. The retention time of the precipitation treatment is usually 0.1.
5h to 2h. After the precipitation treatment, rolling at a rolling ratio of 20% or more is performed. This is because the fin material is work-hardened, and unless this treatment is performed, a high-strength fin cannot be obtained due to recovery during the precipitation treatment. When the rolling ratio is less than 20%, the fins are not sufficiently work-hardened, so the rolling ratio is determined to be 20% or more. The above is the method for producing the alloy fin material of the present invention,
When assembled as a heat exchanger, it is easiest to use it in combination with a heat exchanger tube coated with a low melting point brazing material. In this case, the coating of the wax is usually performed by a method such as thermal spraying, molten metal plating, electroplating, or vapor deposition. The thickness of the fin of the present invention is 120 μm.
m or less.

[0006]

The present invention will be specifically described below with reference to examples. Aluminum alloy fin materials (sheet thickness 100 μm) having the compositions shown in Tables 1 and 2 were produced by the manufacturing methods shown in Tables 3 to 6. The obtained fin material was combined with the following tube material and header material to assemble a radiator shown in FIG. JISA3003 alloy as the core material, JISA on one side
Plate thickness 0.4 of 7072 alloy clad at 10%
mm and 1.2 mm coiled plate members were manufactured by a normal hot pressing method. Using this coil-shaped plate material, hot-dip plating of Zn-11wt% Al (melting point 425 ° C) brazing material was applied on the opposite side of the JIS A7072 cladding layer to a thickness of 0.4 mm.
Is plated with a thickness of 20 μm on
The 80 mm thick coiled plate was plated. In the case of a coil-shaped plate material having a plate thickness of 0.4 mm, a slit material having a width of 35.0 mm was formed by slitting according to the size of the ERW pipe. Using this strip material with an electric resistance welded pipe manufacturing device, the outer
It was processed into an electric resistance welded tube for a liquid passage tube having a thickness of 6.0 mm and a thickness of 2.2 mm. In the case of a coil-shaped plate material having a thickness of 1.2 mm, it was slit to a width of 60 mm to form a strip material for a header. After degreased, the assembled radiator is coated with a 10% concentration solution of a fluoride-based flux having a basic composition of AlF ₃ and CsF, and inserted into a furnace in a nitrogen gas atmosphere at a dew point of −40 ° C. maintained at a temperature of 450 ° C. Brazed. At the same time, the fin material was heated, and the tensile strength of the fin material after brazing was measured. As a conventional method for comparison, the core material is JIS 30
03 alloy and JISA7072 alloy and JISA4343
A similar radiator was assembled using a brazing sheet of the same configuration obtained by hot pressing an alloy with AlF ₃ and KF.
Was applied at a concentration of 10% of a fluoride-based flux having the following basic composition, and brazed at a temperature of 600 ° C. in the same furnace as above. At the same time, the fin material was heated, and the tensile strength of the fin material after brazing was measured. Examination of the joining condition after brazing (Table 7) shows that the radiator using the material according to the present invention has a good joining condition between the fin and the ERW pipe, and is similar to the comparative product using the conventional brazing sheet. Was. Further, the radiator was subjected to a salt spray test based on JISZ2371 for 1000 hours. The pitting corrosion generated in the ERW tube material was evaluated as "O" when the material was equivalent to the conventional material, and as "Poor" when the material was inferior to the conventional material. Table 7 shows the results. The radiator using the fin material of the present invention has the same corrosion resistance as the conventional material. Further, the tensile strength after brazing is shown in Table 7, and the fin material of the present invention shows an extremely high value as compared with the conventional material.

[0007]

[Table 1]

[0008]

[Table 2]

[0009]

[Table 3]

[0010]

[Table 4]

[0011]

[Table 5]

[0012]

[Table 6]

[0013]

[Table 7]

[0014]

As described above, the fin material of the present invention is 500
When brazing is performed at a low temperature of not more than ° C., the brazing properties are not impaired, the strength is high, the sacrificial effect is obtained, and an industrially remarkable effect is achieved.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view showing a radiator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat tube 2 Fin 3 Header 4 Tank

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C22F 1/04-1/057 B22D 11/00 C22C 1/02 C22C 21/00-21/18

Claims (5)

(57) [Claims] 1. Fe content exceeding 3.0 wt% and 12.0 wt %
It contained the following, Zn0.3~2.0wt%, In0.0
It contains one or more of 3 to 0.3 wt% and 0.03 to 0.3 wt% of Sn, and has a plate thickness of 10 mm or less from an Al alloy melt composed of the balance of Al and inevitable impurities .
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized in that a plate is quenched and then processed to a final thickness by rolling . 2. More than 3.0 wt% Fe and 12.0 wt %
It contained the following, Zn0.3~2.0wt%, In0.0
3 to 0.3 wt%, Sn 0.03 to 0.3 wt%, one or more of them, and further contains V, Cr, M
n, Ni, Ti, Zr, Mo, Co, W each 0.1 ~
One or more of the 5.0 wt% of the total of 16 wt.
quenching casting of a plate with a plate thickness of 10 mm or less from an Al alloy melt containing less than wt% and the balance of Al and unavoidable impurities
And method for producing a low temperature brazing aluminum alloy sacrificial fin material, characterized in that for machining to final thickness by rolling. 3. More than 3.0 wt% Fe and 12.0 wt %
It contained the following, Zn0.3~2.0wt%, In0.0
One or more of 3 to 0.3 wt% and 0.03 to 0.3 wt% of Sn;
2.5 wt%, Mg 0.1-0.5 wt%, Cu0.1
Contains one or more of 1.5 wt%,
From molten aluminum alloy consisting of residual Al and unavoidable impurities
A plate with a thickness of 10 mm or less is quenched and cast, and the final plate is rolled.
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized by performing processing up to a thickness . 4. More than 3.0 wt% Fe and 12.0 wt %
It contained the following, Zn0.3~2.0wt%, In0.0
Contains one or more of 3 to 0.3 wt% and Sn 0.03 to 0.3 wt%, and contains V, Cr, Mn, N
i, Ti, Zr, Mo, Co, W each 0.1 to 5.0
16% by weight of one or more of wt%
0.1 to 2.5 wt% of Si, Mg
One or more of 0.1 to 0.5 wt% and 0.1 to 1.5 wt% of Cu, and a plate thickness of 10 mm or less than the molten Al alloy consisting of the balance of Al and inevitable impurities .
A method for producing a high-strength aluminum alloy sacrificial fin material for low-temperature brazing, characterized in that a plate is quenched and then processed to a final thickness by rolling . 5. A temperature of 300 ° C. to 450 ° C. before or during rolling.
Deposition treatment at ℃, until the final plate thickness after the precipitation treatment
The rolling rate is set to 20% or more.
High-strength aluminum alloy sacrificial for low-temperature brazing described in No. 4
Manufacturing method of fin material .