JPH09157807A - Production of aluminum alloy fin material for brazing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an Al-Ni base alloy fin material excellent in brazability. SOLUTION: At the time of producing an aluminum alloy fin material contg., by weight, >0.005 to 0.8% Si, >0.03 to 2.5% Fe, >0.1 to 2.0% Ni, and the balance aluminum with inevitable impurities, after semicontinuous casting, hot rolling is executed without executing heating to >470 deg.C, and process annealing is executed so as to regulate the final cold rolling ratio to 7 to 19%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a highly heat conductive aluminum alloy fin material capable of being thinned,
In particular, the present invention relates to a method for manufacturing a fin material used for radiators, heaters, condensers and the like of automobile heat exchangers manufactured by a brazing method.

[0002]

2. Description of the Related Art Most of heat exchangers for automobiles are made of Al or Al alloy and manufactured by a brazing method. Al-Si type brazing material is usually used as the brazing material and is brazed by heating to a high temperature of about 600 ° C. In a heat exchanger such as a radiator, for example, as shown in FIG. 1, thin fins 20 processed into a corrugated shape are integrally formed between a plurality of flat tubes 10, and the flat tubes 10 have headers 30 at both ends. Each of them is opened in a space formed with the tank 40, and the high-temperature refrigerant is sent from the space on one tank side through the inside of the flat tube 10 to the space on the other tank 40 side, and heat is exchanged at the tubes 10 and fins 20. Then, the refrigerant having a low temperature is circulated again.

By the way, in recent years, heat exchangers are in the direction of weight reduction and miniaturization, and therefore, improvement of heat efficiency of the heat exchanger, and further improvement of heat conductivity of the fin material, have been demanded. Then, a fin material having an alloy component close to that of pure aluminum and excellent in thermal conductivity was proposed. However, since this fin material is not strong enough, there is a problem that when the wall thickness is reduced, the fins are crushed during assembly of the heat exchanger or broken during use. Therefore, it has been attempted to add Mn, which is effective for improving the strength of the fin, but there is a problem that Mn re-dissolves in the brazing process to reduce the thermal conductivity of the fin. Under such circumstances, an Al-Ni alloy fin material having improved strength without impairing thermal conductivity has been proposed (JP-A-6-1166).
No. 68).

[0004]

However, when the thickness of the Al-Ni alloy fin material is reduced, the fins are melted during the brazing, and several fins are combined into one. As a result, a new problem arises that the pressure resistance of the heat exchanger decreases. When the melting of the fins progresses, the brazing filler metal is sucked into the gaps between the fins and a plurality of fins are united, and the fins and the brazing filler metal cannot be distinguished (see FIG. 3D).

The present inventors have studied the method for preventing the melting of the Al-Ni alloy fins, found that it can be improved by selecting the hot rolling temperature, the intermediate annealing temperature, etc. during the production, and further research The present invention has been completed by repeating the above.
An object of the present invention is to provide a method for producing an Al-Ni alloy fin material with improved brazability.

[0006]

According to the first aspect of the present invention,
Si exceeding 0.005 wt% and 0.8 wt% or less, exceeding 0.03 wt% 2.
In producing an aluminum alloy fin material containing less than 5 wt% Fe and more than 0.1 wt% and less than 2.0 wt% Ni, and the balance aluminum and unavoidable impurities, after semi-continuous casting, the temperature was raised to over 470 ° C. A method for producing an aluminum alloy fin material for brazing, characterized in that hot rolling is carried out without heating, and after intermediate annealing is carried out at a plate thickness such that the final cold rolling ratio is 7 to 19%.

The invention according to claim 2 exceeds 0.005 wt%
Si less than 0.8 wt%, Fe exceeding 0.03 wt% and less than 2.5 wt%,
Ni over 0.1 wt% and 2.0 wt% or less, 0.3 w over 0.03 wt%
In producing an aluminum alloy fin material containing less than t% Zr and the balance aluminum and unavoidable impurities, after semi-continuous casting, hot rolling was performed without heating to a temperature above 470 ° C, and the final Cold rolling rate is 7 ~
A method for producing an aluminum alloy fin material for brazing, which comprises performing intermediate annealing after a plate thickness of 19%.

The invention according to claim 3 exceeds 0.005 wt%
Si less than 0.8 wt%, Fe exceeding 0.03 wt% and less than 2.5 wt%,
It contains more than 0.1wt% and less than 2.0wt% Ni, and 2.0w
In producing an aluminum alloy fin material containing at least one of t% or less Zn, 0.3 wt% or less In, and 0.3 wt% or less Sn, and the balance aluminum and unavoidable impurities, An aluminum alloy for brazing, characterized in that after continuous casting, hot rolling is carried out without heating to a temperature exceeding 470 ° C, and after intermediate annealing is carried out at a plate thickness with a final cold rolling ratio of 7 to 19%. It is a manufacturing method of a fin material.

The invention according to claim 4 exceeds 0.005 wt%
Si less than 0.8 wt%, Fe exceeding 0.03 wt% and less than 2.5 wt%,
Ni over 0.1 wt% and 2.0 wt% or less, 0.3 w over 0.03 wt%
Contains less than t% Zn, 2.0% less Zn, 0.3w
In producing an aluminum alloy fin material containing 1% or more of Sn of t% or less and Sn of 0.3 wt% or less and the balance aluminum and unavoidable impurities, after semi-continuous casting, 470 ° C. A method for producing an aluminum alloy fin material for brazing, characterized in that hot rolling is carried out without heating to a temperature exceeding the upper limit, and after intermediate annealing is carried out at a plate thickness with a final cold rolling ratio of 7 to 19%. .

According to the fifth aspect of the invention, the ingot is homogenized at 380 to 460 ° C. for 24 hours or less, and the intermediate annealing is performed at 280 to 470 ° C. for 30 minutes to 12 hours. The method for producing an aluminum alloy fin material for brazing according to any one of claims 1 to 4, wherein

The invention according to claim 6 is characterized in that the cold rolling ratio before the final intermediate annealing is 95% to 99.5%, and the aluminum alloy for brazing according to any one of claims 1 to 5. It is a manufacturing method of a fin material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION First, the action of alloying elements in the aluminum alloy used in the present invention and the reasons for limiting the content thereof will be described. Si coexists with Fe or Ni when coexisting with Fe or Ni.
It promotes precipitation of Ni and increases the amount of intermetallic compounds that contribute to dispersion strengthening and improves strength. In addition, the precipitation of Fe and Ni reduces the solid solution amount of Fe and Ni in the fin material and improves the thermal conductivity. If the Si content is 0.005 wt% or less, the effect is not sufficiently obtained, and if it exceeds 0.8 wt%, the effect of promoting the precipitation of Fe and Ni does not change, but the improvement in strength is not expected so much. In addition, the solid solution amount of Si increases and the thermal conductivity sharply decreases. Therefore, Si is more than 0.005 wt% and 0.8 wt% or less. Desirable Si content is 0.03 to 0.2 wt when thermal conductivity is important.
%, And 0.3 to 0.7 wt% when the strength is important. still,
When Si is increased in the range of 0.3 to 0.8 wt%, the strength improvement due to solid solution hardening of Si is larger than the decrease in thermal conductivity.

Fe forms an intermetallic compound and contributes to the improvement of strength. If the content is 0.03 wt% or less, the effect cannot be sufficiently obtained, and if it exceeds 2.5 wt%, the moldability is deteriorated and the fin corrugation becomes difficult. Therefore, Fe is more than 0.03 wt% and 2.5 wt% or less. Ni distributes a fine intermetallic compound in the alloy and contributes to the strength improvement. In particular, when it coexists with Si, it becomes very easy to precipitate, and contributes to the improvement of strength without lowering the thermal conductivity. If the content is 0.1 wt% or less, the effect cannot be sufficiently obtained, and if it exceeds 2.0 wt%, the moldability is deteriorated and the fin corrugated molding becomes difficult. Therefore
Ni exceeds 0.1 wt% and 2.0 wt% or less. Zr enlarges the fin recrystallized grains generated during brazing and heating. If the recrystallized grains are small, the brazing metal is diffused at the grain boundaries during brazing and the fins are likely to be crushed. If the Fe content is relatively large, the recrystallized grains may become fine. Zr may be added in such a case. If the content is 0.03 wt% or less, the effect is not sufficiently obtained, and if it exceeds 0.3 wt%, the ingot is cracked during casting. Therefore, Zr is more than 0.03 wt% and 0.3 wt% or less. From the viewpoint of thermal conductivity, 0.2 wt% or less is desirable.

In the aluminum alloy used in the present invention,
In addition to the above alloying elements, Zn of 2.0 wt% or less, 0.3 wt%
One or more of In and 0.3 wt% or less Sn may be added. These alloy elements are added to give the sacrificial anode effect to the fin material. If they are added in excess of the above amounts, the thermal conductivity will decrease. Of the above elements, In from the viewpoint of thermal conductivity, Zn from the viewpoint of cost.
Is recommended. Inevitable impurities in the aluminum alloy used in the present invention include Ti and B, which are added for refining the ingot structure. Each of these elements is 0.03
There is no problem if it is less than wt%.

The above are the reasons for limiting the alloy composition of the aluminum alloy used in the manufacturing method of the present invention. These are alloys that have been proposed in recent years. In the present invention, when these alloy fins are manufactured in the steps of semi-continuous casting, chamfering, homogenizing treatment, hot rolling, cold rolling, and annealing, heating is performed at a temperature exceeding 470 ° C. after semi-continuous casting. It is characterized by performing hot rolling without any treatment, and performing intermediate annealing at a plate thickness such that the final cold rolling rate becomes 7 to 19%.
Intermediate heating is performed by heating at 380 to 460 ℃ for 24 hours or less.
It is also characterized by heating at 280 to 470 ℃ for 30 minutes to 12 hours, and the cold rolling rate before final intermediate annealing is 95 to 99.5%.
It is also characterized by

The manufacturing method of the present invention is intended to prevent melting of the fins described above. First, a description will be given of the result of the inventors' investigation of fin melting in order to solve the problem. First, when we investigated what kind of alloy the fins melted, the fins did not melt in the conventionally used Al-Mn alloy fins. It was found to be a phenomenon (compared with fins having the same plate thickness and the same hanging amount). It was also found that even with Al-Ni alloys, the phenomenon does not occur when the fin thickness is large, which is a unique phenomenon when thinning is performed. Furthermore, it was also found that it tends to occur in the part where the fin spacing is narrowed when corrugated. When the phenomenon is further investigated based on these, when the heat exchanger is brazed, thermal expansion of the material occurs during heating, and the fin is subjected to force. When it is considered as a force per unit area, it is obvious that the thinner the fin is, the larger the force is. However, since this force is a force for bending the fin, it is proportional to the reciprocal of the square of the thickness of the fin. When brazing is performed under such stress, the fins in the Al-Ni alloy are crushed at the fillet, and there are narrow gaps between the fins. As a result, the fins move and several fins become one.

The manufacturing method of the present invention is intended to prevent such melting of the fins, and the manufacturing method will be described below. In the manufacturing method of the present invention, the fin is a method of manufacturing in the steps of semi-continuous casting, chamfering, homogenizing treatment, hot rolling, cold rolling, and annealing, and semi-continuous casting, especially for chamfering, etc. For those that do not exist, you can follow the usual method. First, it does not specify semi-continuous casting.
The ingot may be manufactured by DC casting or electromagnetic casting which is usually performed. The conditions for the facing are not specified. Chamfering may be carried out before the homogenization treatment also serves as heating in the hot rolling, and may be carried out either before or after the homogenization treatment when the homogenization treatment is separately performed. Chamfering is not necessary in the case of electromagnetic casting. The homogenization treatment may be performed while also performing heating in hot rolling, or may be performed separately without also performing heating in hot rolling, but since the temperature condition of the present invention is extremely low, It is more efficient to combine heating. Homogenization temperature is 4
Do not heat above 70 ° C. The alloy ingot of the present invention produced by the semi-continuous casting method has a supersaturated solid solution of elements such as Ni, and this is precipitated as an intermetallic compound by the homogenization treatment, but when it exceeds 470 ° C, it contains Ni. The intermetallic compound becomes coarse and melting easily occurs.

There are two purposes of refining the intermetallic compound containing Ni in order to prevent melting. One is to coarsen the recrystallized grains generated during brazing and prevent the strength of the fins from being lowered due to grain boundary diffusion. The other is to finely and densely distribute the intermetallic compound containing Ni so that the Si element introduced by diffusion from the brazing alloy during the brazing heating is taken into the intermetallic compound to prevent melting. Here, the homogenizing treatment conditions can achieve the object of the present invention as long as it is not heated to a temperature higher than 470 ° C. Distributed in different states. Considering economy, the time should be within 24 hours. The lower limit of time is 0 hour. This is when industrially heating a semi-continuous ingot,
This is because it takes time to raise the temperature and precipitation occurs during the temperature rise. Considering precipitation during temperature increase,
10 to 200 ° C./h is desirable. The above is the homogenization treatment condition of the present invention, but the temperature rising rate of the homogenization treatment is 20 to 100 ° C / h.
It is the most desirable and recommended condition that the temperature is 400 to 460 ° C. for 30 minutes to 12 hours in view of economy and distribution of intermetallic compounds. Hot rolling may be carried out by an ordinary method, but when heating for hot rolling is carried out separately from the homogenization treatment, the treatment temperature should not exceed 470 ° C. 470
When the temperature exceeds ° C, the intermetallic compound containing Ni becomes coarse and melting easily occurs. There is no particular condition other than this, and hot rolling may be performed by a usual method.

After hot rolling, cooling rolling and annealing are performed.
Cold rolling is performed in several passes, and intermediate annealing is performed on the way. It is indispensable to perform the intermediate annealing at a sheet thickness such that the rolling rate (final cold rolling rate) in the cold rolling from the sheet thickness at the final intermediate annealing to the sheet thickness of the fin becomes 7 to 19%. Final cold rolling rate is 7%
The reason for defining the above is that when cold-rolling a thin product such as a fin, if the cold-rolling rate is small, deviation during rolling tends to occur, and variation in strip thickness accuracy tends to occur. The reason why it is set to 19% or less is to prevent the fins from melting. Usually, the final cold rolling rate is set to 40% or less in consideration of the drooping characteristics of the alloy fin of the present invention and the brazing diffusion state that occurs in the fin at the fillet portion, and when considering the ease of rolling, it is performed at around 25%. It is normal. 19% or less is related to the fact that the heating temperature of the homogenization treatment was limited and the Ni-containing intermetallic compound was finely and densely distributed. That is, by lowering the final cold rolling rate and finely and densely distributing the intermetallic compound, it is possible to obscure the sub-grain boundaries that occur in the previous stage of fin recrystallization during brazing heating. To do. This allows Si from the braze alloy
Is diffused over the entire surface and reacts with all intermetallic compounds that are finely and densely distributed over the entire surface to prevent Si from penetrating into the fin. From the above, the final cold rolling rate is determined to be 7 to 19%, but considering the ease of rolling, the final cold rolling rate of over 10% and 17% or less considering that the effect of melting prevention is particularly exerted. The final cold rolling rate is especially recommended.

The intermediate annealing is performed using a batch type furnace. The conditions are 280 to 470 ℃ for 30 minutes to 12 hours. This is because recrystallization may not be completed at a temperature of less than 280 ° C and a time of less than 30 minutes, and the role of annealing may not be fulfilled. If the temperature exceeds 470 ° C, the intermetallic compound containing Ni becomes coarse and melting easily occurs. Processing over 12 hours is not economical. At the time of annealing, if the intermetallic compound containing Ni is not coarsened and the recrystallization is completed and the economy is taken into consideration, the temperature should be kept at 300 to 400 ℃.
30 minutes to 4 hours is especially recommended. Although the conditions for the final intermediate annealing and the final cold rolling ratio are as described above, the intermediate annealing may be performed after the hot rolling and before the final annealed sheet thickness is reached by the cold rolling. In this case, when a batch type furnace is used, the upper limit temperature and time are set to the above conditions. When using a continuous furnace, the temperature should be below 550 ° C and within 3 minutes. Time is 3
Within minutes, the intermetallic compound containing Ni will not coarsen unless the temperature exceeds 550 ° C. The lower limit condition is not specified. This is because it is not necessary to cause recrystallization in the intermediate annealing on the way.

In order to more effectively carry out the present invention, the cold rolling rate before the final intermediate annealing may be 95% to 99.5%. By setting the cold rolling rate to a high value exceeding 95%, the recrystallized grain size generated in the final intermediate annealing is made fine. The final cold rolling rate of the present invention is small, since the final cold rolling is performed with a thin plate thickness, tension control of rolling is important, but if the crystal grain size is fine, the strength of the plate increases, This is because the fins are less likely to break during rolling. Further, if the recrystallized grain size after the final intermediate annealing is fine, the strain is likely to be uniformly distributed during the final cold rolling, which has an effect of uniformly preventing the melting during brazing. The upper limit of the cold rolling rate is set to 99.5%. This is because edge cracking may occur during cold rolling when the cold rolling rate exceeds 99.5%. The cold rolling may be performed in one pass or may be performed in several passes. The plate thickness of the fin manufactured by the present invention is 0.03 to
The thickness is about 0.1 mm, and particularly when the thickness is reduced to 0.07 mm or less, the effect of the invention is exhibited well. The heat exchanger using the fin of the present invention is a radiator, a condenser, a heater for an automobile.
A tar, an evaporator, an oil cooler and the like can be mentioned, but the invention is not limited thereto. The method of brazing the fins manufactured by the present invention uses a non-corrosive flux brazing method, a flux brazing method, a vacuum brazing method, and an Al—Si—Cu—Zn alloy brazing material which have been conventionally used. Any brazing method such as soldering (Japanese Patent Application Laid-Open No. 7-88634) can be applied.

[0022]

The present invention will be described below in more detail with reference to examples. (Example 1) Aluminum alloys having compositions of Nos. A to J shown in Table 1 were cast by a semi-continuous casting method to obtain a cross-sectional dimension of 60.
A plate-shaped ingot of × 400 to 1000 mm was obtained. Next, this was divided into 2 to 5 parts in the length direction, and both side surfaces were chamfered by 5 mm. This surface-treated material was homogenized, and after the homogenization, hot rolling was started at that temperature. The obtained hot-rolled sheet was divided in the lengthwise direction and cold-rolled with intermediate annealing to produce a fin material having a thickness of 55 μm. Homogenization treatment, hot rolling, cold rolling,
The conditions of the intermediate annealing during cold rolling were variously changed. The manufacturing process is shown in Table 2.

A melting test and a sag test were performed on each of the obtained fin materials. In addition, the strength and conductivity were examined. The melting test was performed using two brazing sheets as shown in FIG.
22mm width fin material 70 corrugated is sandwiched between 60,
After applying a fluoride-based flux, heating was performed for brazing, and the melting state of the fin after brazing was examined. In FIG. 2, 70 is a wire 70 for fixing the two brazing sheets 60. The brazing sheet has a plate thickness of 40% clad with 4045 alloy.
A 0.25 mm tube brazing sheet was used. The pitch of the corrugated is set to 1/2 of the normal pitch to make it easier to make a difference. The brazing heating was performed in nitrogen gas under the conditions of heating at 600 ° C. for 5 minutes. The evaluation criteria of the molten state of the fin will be described with reference to FIG. 3 (photograph of metal structure). Fig. 3 (a) shows that the fins are not melted at all ◎, Fig. 3 (b) shows that melting occurs just before the fins are close to each other, and Fig. 3 (c) shows that the fins are not melted. It was evaluated as Δ when the melting occurred in the narrow space, and as shown in (d) of FIG. In the hanging test, the fin material was projected and brazed and heated with a cantilever having a length of 50 mm, and the hanging amount at that time was measured and evaluated. The conductivity was examined as an index of thermal conductivity. If the conductivity of the fin is improved by 5% IACS, the thermal efficiency of the heat exchanger is improved by about 1%. Table 3 shows the results.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

As is clear from Table 3, the product of the present invention (N
o.1 to 10) did not melt, and tensile strength, conductivity,
It was also excellent in droop resistance. On the other hand, in Nos. 11 and 12 of the conventional products (containing no Ni), although the fins did not melt, the tensile strength, the electrical conductivity, or the drooping resistance decreased. In Comparative Examples Nos. 13, 14, 15, and 17, the temperature of homogenization treatment and hot rolling was too high, and the final cold rolling rate was too large, so that melting proceeded extremely. No.16,19,20 melted because the homogenization temperature was too high. No. 18 had a large final cold rolling rate, so that melting proceeded significantly. In Nos. 14 and 17, the final cold rolling rate was particularly large, so the droop resistance was also reduced.

(Embodiment 2) 6 pieces of No. K among the aluminum alloys shown in Table 1 were DC cast (thickness 400 mm).
Then, both sides of the ingot are chamfered (10 mm on one side), after homogenization treatment,
It was hot rolled at the same temperature and wound into a coil. The hot-rolled material obtained was divided and cold-rolled with intermediate annealing to produce a fin material having a thickness of 60 μm. Homogenization treatment, hot rolling, intermediate annealing, and cold rolling were performed under various conditions.

A melting test and a drooping test were performed on each of the obtained fin materials by the same method as in Example 1. The tensile strength and electrical conductivity after brazing and heating of the products of the present invention were examined. The results are shown in Table 4 together with the production conditions.

[0030]

[Table 4]

As is clear from Table 4, the product of the present invention (No.
Nos. 21 to 25) did not melt the fins and had excellent droop resistance. The tensile strength after brazing is 135MP.
a, the conductivity was 53% IACS, and all showed good values. On the other hand, in Comparative Examples Nos. 26 and 27, the temperatures of the homogenizing treatment and hot rolling were too high and the final cold rolling rate was large. Since the temperature was extremely high, the melting of the fins proceeded very much. No. 29 had a large final cold rolling rate, so that melting occurred. No. 30 had a large final cold rolling rate and a small cold rolling rate before the final intermediate annealing, so that the melting proceeded significantly. In No. 27, the final cold rolling rate was particularly large, so the droop resistance was also reduced.

[0032]

As described above, according to the present invention,
The brazing property of the Al-Ni-based fin material, which has high strength and excellent thermal conductivity, is improved, resulting in a remarkable industrial effect.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a melting test method.

FIG. 3 is a photograph of a metal structure showing criteria for evaluating the melting state of fins.

[Explanation of symbols]

 10 Flat tube 20 Fins 30 Header 40 Tank 50 Brazing material Brazing sheet 70 Wire to secure brazing sheet

Claims (6)

[Claims] 1. Si containing more than 0.005 wt% and 0.8 wt% or less, 0.03
Fe of more than wt% and less than 2.5 wt%, more than 0.1 wt% of 2.0 wt%
In producing an aluminum alloy fin material containing the following Ni with the balance aluminum and unavoidable impurities, after semi-continuous casting, hot rolling was performed without heating to a temperature above 470 ° C, and the final cold Rolling rate is 7 ~ 19%
A method for manufacturing an aluminum alloy fin material for brazing, characterized in that after the intermediate annealing is performed with a plate thickness of: 2. Si of more than 0.005 wt% and 0.8 wt% or less, 0.03
Fe of more than wt% and less than 2.5 wt%, more than 0.1 wt% of 2.0 wt%
The following Ni, containing more than 0.03 wt% and 0.3 wt% or less Zr,
In producing an aluminum alloy fin stock consisting of the balance aluminum and unavoidable impurities, after semi-continuous casting, hot rolling was performed without heating to a temperature above 470 ° C, and the final cold rolling rate was 7 to 19%. A method for manufacturing an aluminum alloy fin material for brazing, characterized in that after the intermediate annealing is performed with a plate thickness of: 3. Si of more than 0.005 wt% and 0.8 wt% or less, 0.03
Fe of more than wt% and less than 2.5 wt%, more than 0.1 wt% of 2.0 wt%
Containing the following Ni, Zn less than 2.0wt%, 0.3wt%
In producing an aluminum alloy fin material containing the following In and one or more kinds of Sn of 0.3 wt% or less, and the balance aluminum and unavoidable impurities,
Aluminum for brazing, characterized in that after semi-continuous casting, hot rolling is performed without heating to a temperature exceeding 470 ° C, and after intermediate annealing is performed at a plate thickness with a final cold rolling rate of 7 to 19%. Method for manufacturing alloy fin material. 4. Si of more than 0.005 wt% and 0.8 wt% or less, 0.03
Fe of more than wt% and less than 2.5 wt%, more than 0.1 wt% of 2.0 wt%
The following Ni, containing more than 0.03 wt% and 0.3 wt% or less Zr,
Furthermore, Zn less than 2.0 wt%, In less than 0.3 wt%, 0.3 wt%
In manufacturing an aluminum alloy fin material containing one or more of the following Sn and the balance aluminum and unavoidable impurities, after semi-continuous casting, 470
Hot rolling without heating above ℃,
A method for producing an aluminum alloy fin material for brazing, which comprises performing after intermediate annealing at a plate thickness such that the final cold rolling rate is 7 to 19%. 5. The ingot homogenization treatment is performed at 380 to 460 ° C. for 24 hours.
Heating condition for no more than 30 hours, intermediate annealing at 280 ~ 470 ℃ 30
The method for producing an aluminum alloy fin material for brazing according to any one of claims 1 to 4, wherein the heating is carried out under the condition of heating for minutes to 12 hours. 6. The cold rolling rate before final intermediate annealing is 95% to 9%.
It is 9.5%, The manufacturing method of the aluminum alloy fin material for brazing in any one of Claim 1 thru | or 5 characterized by the above-mentioned.