JPH09302432A - Brazing sheet for heat exchanger fin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brazing sheet for fin, capable of low temp. brazing and accordingly minimal in the occurrence of buckling in a thin-walled fin member of a heat exchanger during brazing, further capable of brazing together with other low-melting high strength members such as tube material, and further enabling the scrap of ordinary heat exchangers made of Al alloy to be recycled as a raw material for brazing filler metal at the time of manufacture of a new brazing sheet for fin. SOLUTION: An Al alloy, having a composition consisting of, by weight, >0.03-2.5% Si, >0.05-2.0% Fe, >0.05-2.0% Cu, >0.6-2.0% Mn, and the balance Al with inevitable impurities, is used as a core material. Both sides of this core material are clad with an Al alloy brazing filler metal having a composition consisting of, by weight, >7.0-12.0% Si, >0.4-8.0% Cu, >0.5-6.0% Zn, >0.05-1.2% Mn, >0.05-0.5% Fe, and the balance Al with inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fin brazing sheet for a heat exchanger, and more specifically to brazing at a low temperature, and accordingly, a thin fin member of the heat exchanger during brazing. The aluminum alloy heat exchanger can be made smaller and lighter because it has less buckling and can be brazed together with other high-strength members such as tube material. Furthermore, scrap of general Al alloy heat exchanger can be realized. The present invention relates to a brazing sheet for fins, which has excellent recyclability and can be used as a raw material for a brazing filler metal when manufacturing a new brazing sheet for fins.

[0002]

2. Description of the Related Art As an example of a heat exchanger, FIG. 1 is a perspective view of a condenser which is a serpentine type heat exchanger. FIG. 2 is an enlarged perspective view of the extruded flat multi-hole tube 1 used in this condenser. In this condenser, a tube 1 extruded into a flat tubular shape while hot or warm is bent in a meandering shape, and a corrugated brazing sheet fin 2 is attached between the tubes 1. Here, 3 is a connector corresponding to the inlet and outlet of the refrigerant. These members are integrally joined by brazing. The dimensions of the tube 1 and the brazing sheet fin 2 are, for example, in the case of a condenser (Fig. 1), the width of the tube is 22 m.
m × height 5mm × wall thickness 1.0mm, fin width 22mm
× Thickness is about 0.15 mm, and in the case of an evaporator (not shown), the tube is 80 mm wide × 5 m high
m x wall thickness 1.0 mm, fin width 80 mm x thickness 0.1
The thickness is about 2 mm, and the thickness of both the tube material and the fin material tends to be thin in order to reduce the size and weight of the heat exchanger.

For the tube material 1, for example, JIS1050 alloy (purity 99.5 wt% or more of Al), JIS3003 alloy (Al-1.2 wt% M
n-0.1 wt% Cu alloy), or an alloy in which Cu is added in a slightly larger amount to the 3003 alloy in order to improve the strength of the tube material or make the potential noble. The brazing sheet fin 2 is made of an Al-Mn-based or pure Al-based alloy to which Zn is added, for example, in an amount of 1 to 5% as a core material, and both sides thereof are usually made of JIS 4045 alloy (Al-10wt% Si alloy) A clad brazing material is used. The reason for adding Zn to the core material of the fin is to prevent corrosion of the tube material due to the sacrificial anode effect of the fin material.

The brazing sheet referred to here is a plate used for brazing, and is a plate in which an Al-Si brazing material is clad on one or both sides of a core material. Also, in the manufacture of this brazing sheet, a brazing material to be a core material and a brazing material is separately melted and cast into an alloy having a predetermined alloy composition to form an ingot or a thick plate, and both are hot-rolled and rolled. Further, the sheet is cold-rolled (annealed if necessary) to obtain a sheet having a predetermined thickness.

The brazing sheet fin 2, the tube 1, and the connector 3 are assembled by brazing by heating to a temperature of around 600 ° C. As a brazing method, a flux brazing method,
A vacuum brazing method, a non-corrosion brazing method using a non-corrosive flux, etc. are performed.

By the way, in recent years, heat exchangers have been in the direction of weight reduction and downsizing, and therefore, it has been desired to reduce the thickness of each member such as a tube material and a fin material. However, when the brazing sheet fin material is thinned by the conventional method, the following problems occur. That is, the phenomenon that the fins buckle during brazing or the wax diffuses and melts in the fins is more likely to occur as the fins become thinner. When buckling occurs, the heat efficiency of the heat exchanger decreases due to an increase in ventilation resistance.

In addition to the above problems, in recent years, recyclability has been required from the viewpoint of effective utilization of global resources. The heat exchanger for automobiles is removed at the time of dismantling, and is melted as an Al alloy. However, as described above, the Al alloy heat exchanger manufactured by the brazing method has a different alloy composition for each member, and the average composition of the entire heat exchanger contains a large amount of Mn, Si, Zn, etc. It has an odd composition. Therefore, even if the Al alloy heat exchanger manufactured by the brazing method is melted, it can only be used for casting. Considering the future increase in the number of scrapped vehicles and the shift from copper heat exchangers to Al alloy heat exchangers, scraps of Al alloy heat exchangers composed of the above-mentioned components are not for casting, There is an increasing need for fin brazing sheets that can be recycled as is as brazing filler metal for fin brazing sheets for newly manufactured heat exchangers.

[0008] Further, when the brazing sheet made of Al alloy for a heat exchanger is manufactured, the scrap produced in the factory also has an odd average composition when the scrap is melted, so that each member of the brazing sheet (core material, There is a problem that it cannot be developed as a raw material for a brazing material as a skin material). For reference, Table 1 shows, as an example, the average alloy composition after dissolving the scrap of the conventional heat exchanger made of an Al alloy and the conventional scrap at the time of manufacturing the brazing sheet. Si (1.8 ~ 2.5wt%),
Fe (0.2-0.3wt%), Cu (0.1-0.5wt%), Mn (1.0wt
%) And Zn (0.3 to 1.2 wt%) are contained in a considerable amount.

[0009]

The object of the present invention is to enable brazing at a low temperature, which results in less buckling of the thin fin member of the heat exchanger during brazing, and a tube. Since it can be brazed together with other low-melting point high-strength members such as materials, the Al alloy heat exchanger can be made smaller and lighter, and the scrap of the general Al alloy heat exchanger can be used as a new fin. When manufacturing the brazing sheet for
The object is to find a brazing sheet for fins that can be used as a raw material for the brazing filler metal and has excellent recyclability.

[0010]

According to the present invention of claim 1 for solving the above-mentioned problems, an S content of more than 0.03 wt% and 2.5 wt% or less is provided.
i, Fe exceeding 0.05 wt% and 2.0 wt% or less, 2.0 exceeding 0.05 wt% and 2.0
Contains less than wt% Cu, more than 0.6 wt% and less than 2.0 wt% Mn,
An Al alloy, the balance of which is Al and inevitable impurities, is used as a core material, and both sides of the core material have a content of more than 7.0 wt% and not more than 12.0 wt%.
Si, Cu exceeding 0.4 wt% and 8.0 wt% or less, Cu exceeding 0.5 wt% and 6.0 wt%
The following Zn, Mn of more than 0.05 wt% and 1.2 wt% or less, Fe of more than 0.05 wt% and 0.5 wt% or less were contained, and the remainder was clad with an Al alloy brazing material composed of Al and unavoidable impurities. It is a characteristic brazing sheet for fins of heat exchangers,

Further, the invention of claim 2 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
A that contains Mn and the balance is Al and unavoidable impurities
l alloy as the core material, and on both sides of the core material, more than 7.0 wt% 1
2.0wt% or less Si, 0.4wt% to 8.0wt% or less Cu, 0.5wt
%, 6.0 wt% or less Zn, 0.05 wt% to 1.2 wt% or less M
n, containing more than 0.05 wt% and 0.5 wt% or less Fe, and 0.3 wt%
% Of In and 0.3 wt% or less of Sn are contained in one or two kinds, and the balance is clad with an Al alloy brazing material composed of Al and unavoidable impurities. It is a brazing sheet,

Further, the invention of claim 3 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
It contains Mn and contains one or more of Zn of more than 0.05 wt% and 5.0 wt% or less, In of 0.3 wt% or less and Sn of 0.3 wt% or less, and the balance of Al and unavoidable impurities. Made of Al alloy as a core material, and on both sides of the core material, more than 7.0 wt% and 12.0 wt%
Si below 0.4wt% over 8.0wt% Cu below 0.5wt%
Zn below 6.0wt%, Mn above 0.05wt% and below 1.2wt% 0.05
A brazing sheet for fins of a heat exchanger, characterized by containing an Al alloy brazing material containing more than wt% and 0.5 wt% or less of Fe and the balance being Al and inevitable impurities,

Further, the invention of claim 4 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
It contains Mn and contains one or more of Zn of more than 0.05 wt% and 5.0 wt% or less, In of 0.3 wt% or less and Sn of 0.3 wt% or less, and the balance of Al and unavoidable impurities. Made of Al alloy as a core material, and on both sides of the core material, more than 7.0 wt% and 12.0 wt%
Si below 0.4wt% over 8.0wt% Cu below 0.5wt%
Zn below 6.0wt%, Mn above 0.05wt% and below 1.2wt% 0.05
It contains more than 0.5 wt% and less than 0.5 wt% Fe.
A brazing sheet for fins of a heat exchanger, characterized by containing an Al alloy brazing material containing In and one or two kinds of Sn of 0.3 wt% or less and the balance being Al and inevitable impurities. .

Further, the invention of claim 5 is more than 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
Containing Mn, further 2.0 wt% or less Ni, 0.5 wt% or less Mg, 0.
An Al alloy containing 1% or more of 3 wt% or less of Cr, 0.3 wt% or less of Zr, and 0.3 wt% or less of Ti, with the balance being Al and inevitable impurities as a core material, and the core Si on both sides of the material exceeding 7.0 wt% and 12.0 wt% or less, and exceeding 0.4 wt% and 8.0 w
Contains t% or less Cu, 0.5% to 6.0% by weight Zn, 0.05% to 1.2% by weight Mn, 0.05% to 0.5% by weight Fe, and balance Al. A brazing sheet for fins of a heat exchanger, which is characterized in that an Al alloy brazing material composed of specific impurities is clad.

Further, the invention of claim 6 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
Containing Mn, further 2.0 wt% or less Ni, 0.5 wt% or less Mg, 0.
An Al alloy containing 1% or more of 3 wt% or less of Cr, 0.3 wt% or less of Zr, and 0.3 wt% or less of Ti, with the balance being Al and inevitable impurities as a core material, and the core Si on both sides of the material exceeding 7.0 wt% and 12.0 wt% or less, and exceeding 0.4 wt% and 8.0 w
Cu less than t%, Zn over 0.5wt% and under 6.0wt%, Mn over 0.05wt% and under 1.2wt%, Fe over 0.05wt% and under 0.5wt%, and 0.3wt% under 1 of In and Sn of 0.3 wt% or less
A brazing sheet for fins of a heat exchanger, characterized in that it contains an Al alloy brazing filler metal containing one or two kinds and the balance Al and unavoidable impurities,

Further, the invention of claim 7 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
Mn, 0.05 wt% to 5.0 wt% or less Zn, 0.3 wt% or less In, 1 wt% or more of Sn 0.3 wt% or less, further 2.0 wt% or less Ni, Al containing one or more of 0.5 wt% or less of Mg, 0.3 wt% or less of Cr, 0.3 wt% or less of Zr, and 0.3 wt% or less of Ti, with the balance being Al and inevitable impurities. Using alloy as core material, 7.0w on both sides of the core material
Si over t2.0 and under 12.0wt%, over 0.4wt% and under 8.0wt%
Cu, Zn exceeding 0.5 wt% and 6.0 wt% or less, 1.2 w exceeding 0.05 wt%
Contains less than t% Mn and more than 0.05 wt% and less than 0.5 wt% Fe,
A brazing sheet for fins of a heat exchanger, characterized in that the rest is clad with an Al alloy brazing material consisting of Al and unavoidable impurities,

Further, the invention of claim 8 exceeds 0.03 wt%
2.5 wt% or less Si, more than 0.05 wt% and 2.0 wt% or less Fe, 0.05
Cu of more than 2.0% and less than 2.0% by weight of 0.6% by weight
Mn, 0.05 wt% to 5.0 wt% or less Zn, 0.3 wt% or less In, 1 wt% or more of Sn 0.3 wt% or less, further 2.0 wt% or less Ni, Al containing one or more of 0.5 wt% or less of Mg, 0.3 wt% or less of Cr, 0.3 wt% or less of Zr, and 0.3 wt% or less of Ti, with the balance being Al and inevitable impurities. Using alloy as core material, 7.0w on both sides of the core material
Si over t2.0 and under 12.0wt%, over 0.4wt% and under 8.0wt%
Cu, Zn exceeding 0.5 wt% and 6.0 wt% or less, 1.2 w exceeding 0.05 wt%
Contains less than t% Mn and more than 0.05 wt% and less than 0.5 wt% Fe,
Further, a heat exchanger characterized by containing an Al alloy brazing material containing 0.3% by weight or less of In and 0.3% by weight or less of Sn, and the balance being Al and inevitable impurities. It is a brazing sheet for fins.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION First, a core material and a skin material (a brazing material) constituting a brazing sheet for fins according to the present invention.
The concept of deciding the alloying element of is explained. As a result of various studies on the characteristics of fin brazing sheets for heat exchangers made of Al alloys such as condensers and evaporators, the most necessary characteristic for reducing the thickness and weight is improving the buckling resistance of the fins. In addition, other issues are general A
The scrap of the 1-alloy heat exchanger is to find a brazing sheet for fins having excellent recyclability that can be used as a raw material for the brazing filler metal when manufacturing a new brazing sheet for fins.

First, the improvement of the buckling resistance of the fin will be described. The heating temperature when an Al alloy heat exchanger is manufactured by the brazing method is usually around 600 ° C. Since the temperature of 600 ° C. is a considerably high temperature for Al alloys, there arises a problem that the fins buckle during heating and a high-strength alloy member having a low melting point cannot be used as a core material of the fins. The solutions to these problems are:
Lowering the brazing temperature is effective. If the brazing temperature is 585 ° C or less, buckling of the fins during brazing is less likely to occur, and the high core content of the fins is increased by increasing the Si content. Strength alloy members can also be used. This will be described in more detail below. Most of the fin buckling is caused by the high temperature creep phenomenon of the fin core. This buckling occurs rapidly at around 590 ° C at higher temperatures (fins become weaker). Therefore, if the brazing temperature is 585 ° C. or less, buckling of the fin due to this is unlikely to occur. Another cause of buckling of fins is the diffusion of wax into the fin core. Wax diffusion occurs rapidly around 595 ℃ and at higher temperatures. Therefore, if the brazing temperature is 585 ° C. or lower, the diffusion of the brazing is reduced, and the fins are less likely to buckle. When the brazing temperature is lowered, the alloying element of the fin core material is increased to improve the strength. That is, when the alloying element of the core material is Cu, Cu can be added only up to 1 wt% at a brazing temperature of 600 ° C, but if the brazing temperature reaches 585 ° C,
It can be added up to about 2.5 wt% and the strength of the core material can be increased and the fins can be made thinner. The present invention has such a low temperature (5
This is a brazing sheet for fins that can be brazed at 85 ° C or lower).

Now, the inventors of the present invention have proposed a brazing material (Al-Si-Cu-Zn-based alloy) for brazing at a temperature lower than the normal brazing temperature (about 600 ° C.) as described above.
It was previously proposed (Japanese Patent Laid-Open No. 7-24593, etc.). This brazing material and the brazing material used in the present invention (Al-Si-Cu-Zn-M
The major difference with the n-type alloy is that the brazing filler metal used in the present invention is
With the addition of Mn, the corrosion resistance of the brazing material itself is improved, and the scrap of the Al alloy heat exchanger produced by the brazing sheet and the factory scrap of the brazing sheet are produced during the production of a new fin brazing sheet. This is because the recyclability that can be used as a brazing material is taken into consideration.

With respect to the alloy composition of the brazing filler metal used in the brazing sheet for fins according to the present invention, the significance of the additional elements and the reasons for limiting the composition range will be described below. The braze alloy used in the present invention has an alloy composition of more than 7.0 wt% and 12.0 wt% or less Si, 0.4 wt% or more and 8.0 wt% or less Cu, and more than 0.5 wt% 6.
Zn below 0wt%, Mn above 0.05wt% and below 1.2wt%, 0.05wt
%, 0.5 wt% or less of Fe, and the balance of Al and inevitable impurities in the Al alloy (claims 1, 3, 5, and 7), and the Al alloy further containing 0.3 wt% or less of In , 0.3w
It is an Al alloy in which one or two kinds of Sn of t% or less are added (claims 2, 4, 6, 8).

[Brazing Material Related to Claims 1, 3, 5, and 7] Si
Lowers the melting point of the alloy, but if the amount is 7.0 wt% or less, the melting point does not decrease sufficiently and brazing cannot be performed at a temperature of 585 ° C or lower. On the other hand, if the amount exceeds 12.0 wt%, the melting point rises conversely, so that brazing cannot be performed at a temperature of 585 ° C. or less.
Therefore, the Si content is more than 7.0 wt% and 12.0 wt% or less.

Cu lowers the melting point of the alloy and improves the fluidity of the braze. Here, when the amount of Cu is 0.4 wt% or less, the effect is not sufficient, and when the amount exceeds 8.0 wt%, the rolling workability of the brazing alloy is deteriorated, and it becomes difficult to make a brazing sheet for fins. Therefore, Cu is more than 0.4 wt% and 8.0 wt% or less, but 1.0 wt% when considering the fluidity of the wax at low temperature.
It is more preferable to add 4.0 wt% or less in consideration of the above-mentioned addition and rolling property.

The addition of Zn lowers the melting point of the alloy. Further, in the brazing alloy to which Cu is added as in the present invention, there is a problem that the electric potential of the brazing becomes nobler than the electric potential of the passage forming member such as the tube, and external corrosion progresses in a pit shape and its speed is high. The addition of Zn lowers the electric potential of the wax, brings the electric potential of the wax closer to the electric potential of the passage forming member, and improves the corrosion resistance of the passage forming member such as a tube. However, if the amount is 0.5 wt% or less, the above effect is not sufficient, and if the amount exceeds 6.0 wt%, the self-corrosion resistance of the brazing is reduced, and the rolling workability of the alloy is reduced, and the brazing sheet for fins is used. It becomes unsuitable for use in. Therefore, Zn is set to more than 0.5 wt% and 6.0 wt% or less, but it is more preferable to add 2.0 wt% or more in consideration of the fluidity of the wax at a low temperature and 5.0 wt% or less in consideration of rolling property.

Mn improves the corrosion resistance of the braze itself by using an intermetallic compound, which is produced when the braze solidifies after melting, as an Mn-based compound. That is, in an alloy to which Mn is not added, an Al-Fe-Si-based intermetallic compound containing Fe is generated at the time of solidification, which is the starting point of corrosion, but in the present invention, Mn is contained in this compound. The characteristics of the intermetallic compound change, and the corrosion resistance is significantly improved. In order to exert such effects, Mn exceeding 0.05 wt% is required, and 1.2 wt%
If it exceeds, a coarse Mn-based compound is formed, the formability as an alloy deteriorates, and it becomes impossible to process after casting. Therefore, Mn is
It exceeds 0.05 wt% and 1.2 wt% or less, but considering corrosion resistance
0.8w when added over 0.1wt% and considering the fluidity of wax
It is more preferable to add t% or less.

Fe has the function of refining the crystal grains when the brazing solidifies after melting and increasing the strength of the fillet, but if the amount is less than 0.05 wt%, it does not exhibit sufficient effect. Further, as described above, Fe forms an intermetallic compound upon solidification, which is a starting point of corrosion. When the amount of Fe increases, Fe that does not form a compound with Mn is generated. Therefore, the amount of Fe is 0.05 wt% from the balance between the grain refinement effect and the corrosiveness.
Is determined to be 0.5 wt% or less, and the upper limit is more preferably 0.2 wt% or less from the viewpoint of corrosion resistance.

[Claims 2, 4, 6 and 8 Related Brazing Material] The above are the essential additional elements of the brazing material according to the present invention. However, the present brazing material further contains In and Sn if necessary. May be added. In and Sn make the electric potential of the brazing base metal and improve the corrosion resistance of the refrigerant passage constituting member by this sacrificial anode effect. In other words, to help the effect of Zn in the brazing material,
Add within 0.3 wt% or less. If the amount exceeds 0.3% by weight, the rolling workability of the alloy decreases. More preferred ranges are each 0.01 to 0.3 wt%. One or two kinds of In and Sn are added within the above range.

Next, as the inevitable impurities of the brazing filler metal of the fin brazing sheet of the present invention, Ni, Cr, Zr, Ti,
There are Mg etc. Ni is an element recently used as an element that enhances the strength of alloys for heat exchangers, and is an element that cannot be ignored when recycling scraps of Al alloy heat exchangers to brazing filler metal. Since the characteristics of Ni are almost the same as those of Fe,
Ni as an unavoidable impurity is not particularly problematic if it is 0.5 wt% or less. Further, Cr, Zr, Ti, Mg and the like as unavoidable impurities have no particular problem as long as each is 0.30 wt% or less.

Another characteristic of the brazing filler metal for the fin brazing sheet of the present invention is the alloy composition in consideration of recyclability. The alloying elements of the members used in the conventional Al alloy heat exchanger include Z for imparting the sacrificial anode effect in fins and the like.
n, Si contained in a large amount in the brazing material, Cu, Mn, etc. for improving the strength of the core material. Since the scrap of the Al alloy heat exchanger contains all of these alloy elements, it cannot be developed as a raw material for a new brazing sheet (particularly a brazing material) to be a heat exchanger member. After all, the scrap of the Al alloy heat exchanger is used as a raw material for casting, but these are only reused, and from the viewpoint of resource saving, the Al alloy heat exchanger scrap is changed to a heat exchanger member. True recycling of raw materials for new brazing sheets (especially brazing materials) is desirable.

The alloying elements of the brazing filler metal used in the fin brazing sheet of the present invention are Si, Cu, Zn, Mn, Fe, and I
n and Sn, which contain all the elements usually added to the members of the Al alloy heat exchanger manufactured by the brazing method. That is, the brazing filler metal for a fin brazing sheet of the present invention is a brazing filler metal for a fin, when a scrap of a conventional general Al alloy heat exchanger is used as a member for a heat exchanger to produce a new brazing sheet for fins. It is an alloy that can be recycled as a raw material. Factory waste generated during factory production of the fin brazing sheet of the present invention can also be recycled to this brazing filler metal.

Next, the alloy composition of the core material used in the fin brazing sheet of the present invention will be described. The core material used in the present invention is more than 0.03 wt% and 2.5 wt% or less of Si, 0.05 wt%
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, the balance being Al
0.05% by weight in addition to the Al alloy (relating to claim 1 and claim 2) and the core material according to claim 1 consisting of unavoidable impurities
Over 5.0wt% Zn, 0.3wt% or less In, 0.3wt% or less
Al alloy containing one or more of Sn (related to claims 3 and 4), and the core material according to claim 1, further containing 2.0 wt% or less of Ni, 0.5 wt% or less of Mg, C less than 0.3wt%
Al alloy containing 1 or 2 or more of r, 0.3 wt% or less of Zr, and 0.3 wt% or less of Ti (related to claims 5 and 6),
In addition to the core material of claim 1, the content is more than 0.05 wt% and 5.0 w.
Zn of t% or less, In of 0.3 wt% or less, and Sn of 0.3 wt% or less 1
Or two or more and 2.0 wt% or less of Ni, 0.5 wt% or less of Mg,
It is an Al alloy containing one or more of Cr of 0.3 wt% or less, Zr of 0.3 wt% or less, and Ti of 0.3 wt% or less (claims 7 and 8).

The significance of the elements added to the core alloy and the reasons for limiting the range of addition will be described below. [Core materials according to claims 1 and 2] Si contributes to strength improvement.
If Si is 0.03 wt% or less, the effect is not sufficient, and if it exceeds 2.5 wt%, the melting point is lowered, and even when the brazing material of the present invention is used, it is melted during brazing. Therefore, Si is more than 0.03 wt% and 2.5 wt% or less, but 0.3 wt% to 1.0 wt% is more preferable in consideration of the balance of corrosion resistance and brazing property, and 0.5 wt% or more is more preferable in consideration of strength. .

Fe distributes a coarse intermetallic compound in the alloy to make the crystal grains of the core material fine and prevent cracks during molding. If the amount is less than 0.05% by weight, the effect cannot be sufficiently obtained, and if it exceeds 2.0% by weight, the formability is conversely reduced, and the brazing sheet breaks during the forming process. Therefore, the content of Fe should be more than 0.05 wt% and not more than 2.0 wt%.

Cu contributes to the improvement of strength. Cu is 0.05wt%
In the following, the effect is not sufficient, and when it exceeds 2.0 wt%, the melting point is lowered, and even when the brazing material of the present invention is used, it melts during brazing. Therefore, the Cu content is more than 0.05 wt% and 2.0 wt% or less.

Mn is an essential element for distributing a fine intermetallic compound in the alloy and improving the strength without lowering the corrosion resistance. If the amount is 0.6 wt% or less, a sufficient effect cannot be obtained, and if it exceeds 2.0 wt%, the formability is lowered and the brazing sheet is cracked during the forming process. Therefore,
Mn exceeds 0.6 wt% and 2.0 wt% or less.

[Core Material Related to Claims 3, 4, 7, and 8] In addition to the above, Zn, In, and Sn are elements added to impart a sacrificial anode effect to the fin material. If Zn is 0.05 wt%, the effect is not obtained, and if it exceeds 5.0 wt%, the thermal conductivity decreases. Further, if In and Sn exceed 0.3 wt%, the thermal conductivity is lowered. Therefore, Zn, In, and Sn are more than 0.05 wt% and 5.0 wt% or less Zn,
One or more of In of 0.3 wt% or less and Sn of 0.3 wt% or less are added. [Core materials related to claims 5, 6, 7 and 8] In addition to the above, Cr and Z
Both r and Ti form a fine intermetallic compound and contribute to the improvement of the strength and corrosion resistance of the alloy. If Cr, Zr, and Ti are added in excess of 0.3 wt%, the formability is lowered, and the fin brazing sheet is cracked during processing such as assembly. Therefore, if added, the content of each should be 0.3 wt% or less.

Further, Ni has the function of distributing a fine intermetallic compound in the alloy and improving the strength of the alloy. Ni
Is an optional alloying element and may not be added if recyclability and cost are taken into consideration. If the content is more than 2.0 wt%, the moldability will be deteriorated and the fin brazing sheet will be cracked during the molding process. Therefore, if added, the content should be 2.0 wt% or less.

[0038] Mg improves the strength of the alloy by solution hardening. If Mg is contained in excess of 0.5 wt%, brazing properties will decrease when a potassium fluoride-based flux is used. Therefore, when added for the purpose of improving the strength, 0.
5 wt% or less. Mg is an optional alloy element to be added, and it is better not to contain Mg from the viewpoint of material recyclability. When Cr, Zr, Ti, Ni, and Mg are added according to the purpose, for each element, one or two kinds in the above range may be used.
Add more than one seed.

The above is a description of the alloying elements of the core material used in the present invention. B added for refining the structure of the ingot, V added for the purpose of improving strength, and other unavoidable elements. There is no problem even if they are included as long as they are 0.05 wt% or less.

The brazing sheet for fins of the present invention (claims 1 to 8) has the above-mentioned Al content depending on the purpose of use and application.
An alloy brazing material and the Al alloy core material described above are appropriately selected and combined, and a brazing material is clad on both surfaces of the core material. The thickness of the brazing sheet for fins of the present invention can be made thinner than the conventional one for the reasons described above, and can be 0.08 to 0.12 mm depending on the application. The clad ratio of the brazing material is about 5 to 15% of the total plate thickness on one side,
It changes according to the plate thickness. Generally, the thicker the plate, the smaller it becomes. The temper of the fin brazing sheet of the present invention is not particularly specified. Considering formability etc., H1n material, H2n
The material may be appropriately selected from H3n material and the like.

The fin brazing sheet of the present invention comprises:
Mainly used for manufacturing Al alloy heat exchangers. The Al alloy heat exchanger referred to here is a condenser, evaporator, radiator, heater, oil cooler,
However, the present invention is not limited to these. The fin brazing sheet of the present invention is mainly used for heat exchangers, but can be used for other purposes.

The fin brazing sheet of the present invention comprises:
It is recommended that the brazing temperature be higher than 570 ° C and lower than 585 ° C. The reason is that when the brazing temperature is 570 ° C. or lower, the brazing material of the present invention does not melt compositionally and cannot be brazed. If the temperature exceeds 585 ° C, the buckling resistance of the brazing sheet for fins at high temperature will decrease,
This is because it is impossible to use another member for forming the refrigerant passage, which is made of a high-strength alloy having a low melting point and containing a large amount of Si, Cu, and the like. By lowering the brazing temperature in this way, it is possible to obtain the effect of extending the life of the brazing furnace.

Here, in the brazing sheet for fins of the present invention, the brazing temperature is limited, but other brazing conditions may be almost the same as the conventional one. That is, any brazing method such as a flux brazing method, a vacuum brazing method, and a non-colloidal brazing method using a non-corrosive flux can be applied. Assembling, cleaning, and optionally applying a flux before brazing may be performed as usual.

[0044]

EXAMPLES Hereinafter, examples of the brazing sheet for fins according to the present invention will be described more specifically in comparison with comparative examples and conventional examples. As an example of the scrap material, Table 1 shows an average alloy composition obtained by melting and casting brazing sheet factory scraps produced during factory production and scraps of Al alloy heat exchangers.

[0045]

[Table 1]

In Table 1, the brazing sheet mill waste for fins is mainly a brazing sheet or the like in which Al-Si-based alloy skin material is clad on both sides of an Al-Mn-Zn-based alloy core material as a brazing material. It is factory scrap. Tube brazing sheet factory waste is mainly Al-Mn-
Factory waste such as a brazing sheet or the like in which a Cu-based alloy core material is clad on one surface with an Al-Si-based alloy as a brazing material and on the other surface with an Al-Zn-based alloy as a sacrificial material. The heat exchanger scrap is an Al alloy radiator,
On one surface of the core material of the Mn-Cu alloy, Al-
Si-based alloy, tube material with other surface clad with Al-Zn-based alloy as a sacrificial material, header material and Al-Mn-Zn
It is composed of a fin material of a system alloy and others.

The scrap alloys (Nos. 1, 2, 3) shown in Table 1 were blended, and Al alloy brazing materials having various compositions shown in Table 2 were melt-cast. In addition, the brazing alloy material No. A to O,
For R and S, the scrap material is used and Al ingot is added,
Further, Si, Cu, Zn and the like were further added to obtain a predetermined alloy composition. In the production of some of the comparative examples (No. P, Q) in Table 2 and the conventional alloy (No. T), the scrap material could not be used due to the scrap composition. The brazing alloy material contains elements such as Cr, Zr, and Ti as unavoidable impurities in an amount of 0.03 wt% or less, and in particular, the alloy material B contains Ni in an amount of 0.06 wt% or less. Manufacture of these brazing alloy sheets to be used as the skin material was carried out by a conventional method in which DC casting, chamfering, homogenization treatment and hot rolling were performed.

[0048]

[Table 2]

Next, the obtained brazing alloy plates were put on both sides of the core alloy ingot shown in Table 3, heated and clad by hot rolling to obtain a hot rolled plate. Thus, a fin brazing sheet having a brazing material clad on both sides was manufactured by cold rolling and annealing to a predetermined thickness and temper. Table 3 shows the composition of the core alloy ingot, and Table 4 shows the composition of the brazing sheet. As the brazing sheet for fins, H14 tempered material having a plate thickness of 0.10 mm was manufactured. The clad ratio of the brazing material was 10% of the total plate thickness on one side.

[0050]

[Table 3]

[0051]

[Table 4]

After heating the brazing sheet for fins having a thickness of 0.10 mm at the brazing temperature shown in Table 4,
A hanging test and a tensile test were performed. 22 mm width for the hanging test
The sample with the protrusion length of 50 mm was used.

The fin brazing sheet having a thickness of 0.10 mm is corrugated, and the plate thickness above and below the corrugated plate is applied.
Combined with a 0.30 mm 3003 alloy (Al-1.2wt% Mn-0.15wt% Cu alloy) plate to assemble into a single-stage core, and the assembled core contains potassium fluoride flux at a concentration of 10%. The solution was applied and heated in N ₂ gas for brazing. The brazing temperature is also shown in Table 4. With respect to the core after brazing, the crushing condition of the fin and the forming condition of the fillet were examined by visual observation. Table 5 shows the results.

[0054]

[Table 5]

As is clear from Table 5, the fin brazing sheet (N0.1 to 19) of the present invention is a brazing material of the fin brazing sheet in which a scrap material is mixed. It was proved that it is excellent in various characteristics such as droop resistance, tensile strength, and fillet shape, and that resources can be effectively used by recycling scraps to the brazing material of the fin brazing sheet. Furthermore, since the brazing temperature can be lowered, even if a high strength alloy having a low melting point is used as the core material of the brazing sheet for fins, the fins are not crushed during brazing. Therefore, the fin brazing sheet has a conventional plate thickness of 0.1.
It was also confirmed that the thickness was about 5 mm, but the plate thickness of 0.10 mm, which is an example of the present invention, can be thinned without any problem.

On the other hand, in Comparative Example No. 21, 22
The brazing sheet of No. could not be recycled because it did not contain Mn or Cu (the waste material could not be mixed with the brazing material). In addition, No. Since the brazing sheet of No. 21 did not contain Cu, the melting point of the brazing filler was raised, the brazing property was lowered, and the fillet was not sufficiently formed.

No. The brazing sheets 20 and 23 have different compositions from the brazing material composition of the present invention, but the scrap material can be recycled into the brazing material. However, no. 20
In the brazing sheet of No. 3, since the amount of Si in the brazing filler metal was less than the range specified in the present invention, the melting point of the brazing filler metal was high and the brazing property was deteriorated, so that fillets were not sufficiently formed. No.
In the brazing sheet of No. 23, the Mn content of the brazing filler metal was larger than the limit range of the present invention, so that the fluidity of the brazing filler was reduced and no fillet was formed.

No. Since the brazing sheet of No. 24 has a large amount of Si in the core material, at a brazing temperature of 580 ° C,
Since the fin core material was melted during brazing, the characteristic evaluation after brazing could not be performed. In addition, No. 25,
The brazing sheet of No. 26 is an example in which a conventional brazing material is used. Since the brazing material does not contain Mn, Cu or Zn, the scrap material cannot be recycled into the brazing material. Furthermore, since the brazing temperature was as high as 600 ° C, the amount of drooping was large in the sag resistance test, and the fins collapsed.

[0059]

As described above in detail, the fin brazing sheet according to the present invention can be brazed at a low temperature, and the buckling of the thin fin member of the heat exchanger during brazing is accompanied by this. The heat exchanger made of Al alloy can be reduced in size and weight because it can be brazed together with other high strength members such as a tube material. In addition, scraps of general Al alloy heat exchangers and brazing sheet scraps generated in factories can be used as a brazing filler metal in the production of a new brazing sheet for fins according to the present invention and are excellent in recyclability. It has a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a serpentine type capacitor.

FIG. 2 is an enlarged perspective view of the extruded flat multi-hole tube of FIG.

[Explanation of symbols]

 1. Extruded flat multi-hole tube 2. Fin 3. connector

Claims (8)

[Claims] 1. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, the balance being Al
And an unavoidable impurity as an Al alloy as a core material, and on both surfaces of the core material, Si of more than 7.0 wt% and not more than 12.0 wt%, 0.4 wt%
Over 8.0wt% Cu, 0.5wt% over 6.0wt% Zn,
Mn over 0.05 wt% and under 1.2 wt%, 0.5 wt% over 0.05 wt%
A brazing sheet for fins of a heat exchanger, which is characterized in that an Al alloy brazing material containing the following Fe and the balance being Al and unavoidable impurities is clad. 2. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, the balance being Al
And an unavoidable impurity as an Al alloy as a core material, and on both surfaces of the core material, Si of more than 7.0 wt% and not more than 12.0 wt%, 0.4 wt%
Over 8.0wt% Cu, 0.5wt% over 6.0wt% Zn,
Mn over 0.05 wt% and under 1.2 wt%, 0.5 wt% over 0.05 wt%
It contains the following Fe, and further contains less than 0.3 wt% In and less than 0.3 wt%
A brazing sheet for fins of a heat exchanger, characterized by containing one or two kinds of Sn, and the rest being a clad with an Al alloy brazing material composed of Al and unavoidable impurities. 3. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, more than 0.05 wt% and less than 5.0 wt% Zn, 0.3 wt% or less In, 0.3 wt% or less Sn
Al alloy containing at least one of the above and the balance being Al and unavoidable impurities is used as the core material, and Si of more than 7.0 wt% and not more than 12.0 wt%, 0.4 wt. Over%
Cu less than 8.0 wt%, Zn over 0.5 wt% and less than 6.0 wt%, 0.05 wt
% Over 1.2 wt% Mn, over 0.05 wt% over 0.5 wt%
A containing Fe and the balance being Al and unavoidable impurities
A brazing sheet for fins of a heat exchanger, characterized by being clad with an alloy brazing material. 4. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, more than 0.05 wt% and less than 5.0 wt% Zn, 0.3 wt% or less In, 0.3 wt% or less Sn
Al alloy containing at least one of the above and the balance being Al and unavoidable impurities is used as the core material, and Si of more than 7.0 wt% and not more than 12.0 wt%, 0.4 wt. Over%
Cu less than 8.0 wt%, Zn over 0.5 wt% and less than 6.0 wt%, 0.05 wt
% Over 1.2 wt% Mn, over 0.05 wt% over 0.5 wt%
Fe containing, 1 or 2 kinds of In and 0.3 wt% or less of In and 0.3 wt% or less of Sn, and the remainder being clad with an Al alloy brazing material composed of Al and unavoidable impurities Brazing sheet for fins of heat exchangers. 5. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and 2.0 Mwt% or less, and further 2.0 wt%
Contains one or more of the following Ni, 0.5 wt% or less Mg, 0.3 wt% or less Cr, 0.3 wt% or less Zr, and 0.3 wt% or less Ti, with the balance being Al and inevitable impurities. Al alloy consisting of and is used as a core material, and on both sides of the core material, more than 7.0 wt% and 12.0 wt%
Si below 0.4wt% over 8.0wt% Cu below 0.5wt%
Zn below 6.0wt%, Mn above 0.05wt% and below 1.2wt% 0.05
A brazing sheet for fins of a heat exchanger, characterized by containing an Al alloy brazing material containing more than 0.5 wt% and less than 0.5 wt% Fe and the balance being Al and inevitable impurities. 6. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and 2.0 Mwt% or less, and further 2.0 wt%
Contains one or more of the following Ni, 0.5 wt% or less Mg, 0.3 wt% or less Cr, 0.3 wt% or less Zr, and 0.3 wt% or less Ti, with the balance being Al and inevitable impurities. Al alloy consisting of and is used as a core material, and on both sides of the core material, more than 7.0 wt% and 12.0 wt%
Si below 0.4wt% over 8.0wt% Cu below 0.5wt%
Zn below 6.0wt%, Mn above 0.05wt% and below 1.2wt% 0.05
It contains more than 0.5 wt% and less than 0.5 wt% Fe.
A brazing sheet for fins of a heat exchanger, characterized by containing one or two kinds of In and 0.3 wt% or less of Sn, and the remainder being a clad with an Al alloy brazing material composed of Al and unavoidable impurities. 7. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, more than 0.05 wt% and less than 5.0 wt% Zn, 0.3 wt% or less In, 0.3 wt% or less Sn
Containing one or more of the above, and further 2.0 wt% or less
Ni, Mg less than 0.5 wt%, Cr less than 0.3 wt%, Z less than 0.3 wt%
r, an Al alloy containing at least one of Ti of 0.3 wt% or less and the balance of Al and unavoidable impurities as a core material. wt% or less Si, 0.4 wt% or more and 8.0 wt% or less Cu, 0.5 wt% or more 6.
Zn below 0wt%, Mn above 0.05wt% and below 1.2wt%, 0.05wt
A brazing sheet for fins of a heat exchanger, characterized by containing an Al alloy brazing material containing more than 0.5% and 0.5 wt% or less of Fe with the balance being Al and inevitable impurities. 8. Si of more than 0.03 wt% and 2.5 wt% or less, 0.05 wt
%, 2.0 wt% or less Fe, 0.05 wt% or more 2.0 wt% or less
Cu, containing more than 0.6 wt% and less than 2.0 wt% Mn, more than 0.05 wt% and less than 5.0 wt% Zn, 0.3 wt% or less In, 0.3 wt% or less Sn
Containing one or more of the above, and further 2.0 wt% or less
Ni, Mg less than 0.5 wt%, Cr less than 0.3 wt%, Z less than 0.3 wt%
r, an Al alloy containing at least one of Ti of 0.3 wt% or less and the balance of Al and unavoidable impurities as a core material. wt% or less Si, 0.4 wt% or more and 8.0 wt% or less Cu, 0.5 wt% or more 6.
Zn below 0wt%, Mn above 0.05wt% and below 1.2wt%, 0.05wt
% And 0.5 wt% or less of Fe, and 0.3 wt% or less of In
And a brazing sheet for fins of a heat exchanger, characterized in that it contains one or two kinds of Sn of 0.3 wt% or less and the rest is clad with an Al alloy brazing material composed of Al and inevitable impurities.