JPH0931614A - Production of aluminum alloy fin material with high strength and high heat resistance for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fin material increased in fin strength at the time of heat exchanger assembly before brazing, minimal in the occurrence of buckling deformation due to high temp. at the time of brazing, and capable of thickness reduction. SOLUTION: An ingot of Al alloy, having a composition which contains 1.0-2.0% Mn, 0.2-0.8% Si, and small amounts of Zr and/or Cr and in which Fe content is limited to <0.2%, is subjected to homogenizing treatment at 400-550 deg.C for 1-30hr. Subsequently, the ingot is subjected to hot rolling while regulating the initial temp. and finishing temp. of hot rolling to 400-550 deg.C and <=300 deg.C, respectively. The resulting Al alloy plate is subjected, without process annealing, to cold rolling of >=90% and then to final annealing at 150-320 deg.C, or, the Al alloy plate is subjected, after hot rolling without delay or after cold rolling, to process annealing at <320 deg.C, to cold rolling at >50%, and then to final annealing at 150-320 deg.C. Moreover, an alloy, further containing, besides the above component elements, Mg and/or Cu or one or more elements among Zn, Si, In, and Ga, is also subjected to the treatments similar to the above treatments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy fin material used in fins of various heat exchangers such as condensers and evaporators for automobile coolers in the form of a bare material or a brazing sheet core material. In order to prevent deformation and buckling of the fins when assembling the heat exchanger especially when the plate thickness is made thin, the strength before brazing (base plate strength) is increased, and the seat is resistant to high temperatures during brazing. The present invention relates to a method for manufacturing a fin material for a heat exchanger having improved flexibility.

[0002]

2. Description of the Related Art Generally, heat exchangers made of Al alloy have been widely used as heat exchangers for radiators, intercoolers, evaporators, condensers, oil coolers and the like of automobiles. In such an Al alloy heat exchanger, it is usual to assemble by brazing a fin material made of an aluminum alloy to a tube or core plate or pipe through which a temperature medium (working fluid) such as water flows, In this case, the fin material is used as a brazing sheet, that is, as a laminated plate in which a skin material made of an aluminum alloy brazing material is pre-deposited on one or both sides of an aluminum alloy core material, or as a bare material as it is. Is being done. As a core material for such a brazing sheet of a fin material for a heat exchanger or a bare material, a conventional alloy such as 3003 alloy has been used.
An l-Mn alloy is often used.

[0003]

The heat exchanger fin material for automobiles as described above has not only good fin formability at the time of molding such as corrugated molding but also plate thickness such as brazing sheet core. 0.16 mm for wood
Because of its thinness and thinness, it is necessary to have strength that does not cause deformation or buckling of the fins when assembling the heat exchanger, and since it is exposed to a high temperature of around 600 ° C during brazing, the high temperature during brazing It is necessary that the fins have heat resistance such that buckling deformation does not occur, that is, high temperature buckling resistance.

By the way, recent heat exchangers for automobiles are strongly required to be lightweight and small in size, so that the fin material for the heat exchanger is required to be thinner than the conventional one, specifically 0.03 to 0. It is desired to reduce the thickness to about 01 mm. Therefore, in order to prevent deformation and buckling at the time of forming such as corrugated forming, the strength of the base plate before brazing is further strengthened than before, and at the same time buckling deformation at high temperature brazing is performed. It is desired to further improve heat resistance (high temperature buckling resistance) in order to prevent this.

However, in the case of 3003 alloy or the like which has been conventionally used as a fin material, when the wall thickness is reduced to about 0.03 to 0.1 mm, the high temperature buckling resistance is lowered if an attempt is made to increase the strength, so that the heat It is difficult to prevent the deformation and buckling of the fin material when assembling the exchanger and the buckling of the fin material due to high temperature during brazing at the same time. It has been practically difficult to reduce the wall thickness.

The present invention has been made in view of the above circumstances and has a high fin material strength (base plate strength) at the time of assembling a heat exchanger before brazing, and is excellent in high temperature buckling resistance. It is an object of the present invention to provide an aluminum alloy fin material that causes less buckling deformation due to high temperature.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the inventors of the present invention have conducted various experiments and studies, and as a result, based on an Al--Mn--Si alloy, the alloy component of the fin material is appropriately selected. At the same time, the fin material manufacturing process is appropriately selected and the conditions of each step are appropriately determined, so that the strength before brazing is high and the buckling deformation due to high temperature during brazing is small, and the fin material As a result, it was found that a fin material having a sufficient sacrificial anode effect and capable of imparting sufficient corrosion resistance to a heat exchanger can be obtained, and the present invention has been accomplished.

Specifically, in the method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to the invention of claim 1, Mn is 1.0 to 2.0% and Si is 0.2 to 0.8%. Contained, Zr 0.03 to 0.3%, Cr 0.03 to
It contains one or two of 0.3%, and Fe
Is regulated to less than 0.2%, and the balance is subjected to homogenization treatment at 400 to 550 ° C. for 1 to 30 hours on an ingot of an alloy composed of Al and unavoidable impurities, and when hot rolling is performed, heat treatment is performed. The hot rolling start temperature is set to 400 to 550 ° C., the hot rolling end temperature is set to 300 ° C. or less, and cold rolling is performed at a cold rolling rate of 90% or more after the hot rolling is finished to 0.03 to 0.10 mm. It is characterized in that it is a cold-rolled sheet having a thickness within the range of, and further subjected to final annealing at a temperature within the range of 150 to 320 ° C. to obtain a fin material having a tensile strength of 200 N / mm ² or more. is there.

The method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to a second aspect of the invention is Mn.
1.0-2.0%, Si 0.2-0.8% are contained, Zr 0.03-0.3%, Cr 0.03-0.3%
One or two of them, and Fe is 0.2
1 to 30 at 400 to 550 ° C. with respect to the ingot of the alloy which is regulated to less than 10% and the balance is Al and unavoidable impurities.
When the hot homogenization treatment is performed and the hot rolling is further performed, the hot rolling start temperature is set to 400 to 550 ° C., the hot rolling end temperature is set to 300 ° C. or lower, and the cold rolling is performed after the hot rolling is finished. Or without cold rolling,
0.03 to 0.10 m after intermediate annealing at less than 320 ° C. and cold rolling at a cold rolling rate of more than 50%.
Cold rolled sheet with a thickness within the range of m, and further 150 to 320
Final annealing at a temperature in the range of ℃, tensile strength of 20
The feature is that a fin material of 0 N / mm ² or more is obtained.

Further, the method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to the invention of claim 3 is M
n1.0-2.0%, Si0.2-0.8% is contained,
Furthermore, Zr 0.03 to 0.3%, Cr 0.03 to 0.3
%, And 1% or 2% of
It contains one or two of 0.05 to 0.5% and Cu 0.05 to 0.3%, Fe is regulated to less than 0.2%, and the balance is Al and inevitable impurities. The same process as that described in claim 1 is applied to the alloy to obtain a fin material having a tensile strength of 200 N / mm ² or more.

The method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to a fourth aspect of the invention is Mn.
1.0-2.0%, Si 0.2-0.8% are contained, Zr 0.03-0.3%, Cr 0.03-0.3%
1 or 2 of Mg0.
Alloys containing one or two of 0.05 to 0.5% and Cu 0.05 to 0.3%, Fe regulated to less than 0.2%, and balance Al and unavoidable impurities By applying the same process as that described in claim 2, a fin material having a tensile strength of 200 N / mm ² or more is obtained.

Furthermore, the method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to the fifth aspect of the invention is M
n1.0-2.0%, Si0.2-0.8% is contained,
Furthermore, Zr 0.03 to 0.3%, Cr 0.03 to 0.3
%, And one or two of
0.2-2.0%, Sn0.01-0.1%, In0.
Alloy containing 005 to 0.1% and one or more of 0.005 to 0.1% Ga, Fe regulated to less than 0.2%, and balance Al and unavoidable impurities Regarding the above, the same process as described in claim 1 is applied to obtain a fin material having a tensile strength of 200 N / mm ² or more.

The method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to a sixth aspect of the invention is Mn.
1.0-2.0%, Si 0.2-0.8% are contained, Zr 0.03-0.3%, Cr 0.03-0.3%
1 or 2 of ZnO.
2 to 2.0%, Sn 0.01 to 0.1%, In 0.00
Alloy containing 5 to 0.1% and one or more of 0.005 to 0.1% Ga, Fe regulated to less than 0.2%, and balance Al and unavoidable impurities Regarding the above, the same process as that described in claim 2 is applied to obtain a fin material having a tensile strength of 200 N / mm ² or more.

Furthermore, the method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to the invention of claim 7 is M
n1.0-2.0%, Si0.2-0.8% is contained,
Furthermore, Zr 0.03 to 0.3%, Cr 0.03 to 0.3
%, And 1% or 2% of
0.05 to 0.5%, Cu containing one or two of 0.05 to 0.3%, and Zn 0.2 to 2.0%,
Sn 0.01-0.1%, In 0.005-0.1%,
The alloy containing 1 or 2 or more of Ga 0.005 to 0.1%, Fe regulated to less than 0.2%, and the balance being Al and inevitable impurities. A fin material having a tensile strength of 200 N / mm ² or more is obtained by applying the same process as described above.

The method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger according to the invention of claim 8 is Mn.
1.0-2.0%, Si 0.2-0.8% are contained, Zr 0.03-0.3%, Cr 0.03-0.3%
1 or 2 of Mg0.
05 to 0.5%, Cu 0.05 to 0.3%, containing 1 or 2 kinds, and Zn 0.2 to 2.0%, Sn
0.01-0.1%, In 0.005-0.1%, Ga
It contains one or more of 0.005 to 0.1%, Fe is regulated to less than 0.2%, and the balance is A
Applying the same process as described in claim 2 for an alloy consisting of 1 and inevitable impurities,
A fin material having a tensile strength of 200 N / mm ² or more is obtained.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION First, the reasons for limiting the composition of the alloy of the present invention will be explained.

Mn: Mn is a basic alloying component of the fin material alloy used in the present invention, and it forms Al-Mn-Si-based fine intermetallic compound precipitates, and the base plate (before brazing). It is effective for improving the strength of the plate) and the strength after brazing, and also for improving the formability. In addition, Al-Mn-
The Si-based fine intermetallic compound also contributes to the improvement of high temperature buckling resistance by coarsening the recrystallized grains during brazing. If the amount of Mn is less than 1.0%, these effects are not sufficient, while if it exceeds 2.0%, a coarse intermetallic compound is generated during casting, and the rolling property deteriorates, making it difficult to manufacture a plate material. . Therefore, the amount of Mn is set within the range of 1.0 to 2.0%.

Si: Si is also a basic alloying component of the fin material alloy used in the present invention, and it produces Al--Mn--Si based fine intermetallic compound precipitates, and after the original plate strength and brazing, It is an element effective for improving the strength of the alloy and improving the high temperature buckling resistance through the coarsening of recrystallized grains during brazing as described above. Si is Mn
It is effective to reduce the amount of solid solution of (1) to improve the thermal conductivity and to make the electric potential base to enhance the sacrificial anode effect of the fin material. If the Si content is less than 0.2%, these effects are not sufficiently obtained, while if it exceeds 0.8%, the brazing filler metal component, especially Si, penetrates into the fin material during brazing (generally, this There is a possibility that fins may be melted and corrosion resistance may be deteriorated due to erosion. Therefore, the amount of Si is set within the range of 0.2 to 0.8%.

Zr, Cr: Zr and Cr are both effective elements for improving the high temperature buckling resistance, and either one or both are added. In all cases, if the addition amount is less than 0.03%, the effect of improving the high temperature buckling resistance cannot be sufficiently obtained, while if it exceeds 0.3%, a coarse intermetallic compound is generated during casting and the rolling property is improved. And the plate material becomes difficult to manufacture. Therefore, Zr and Cr are both 0.03
Within the range of up to 0.3%.

Mg, Cu: Mg and Cu are effective elements for improving the strength of the base plate and the strength after brazing,
Therefore, in the inventions of claim 3, claim 4, claim 7, and claim 8, either or both of them are added. Among these, Mg has a considerably high cooling rate after brazing and heating in a normal operation, and therefore coexists with Si to cause age hardening and contributes to strength improvement. Mg amount is 0.05%
If less than this effect is not sufficient. On the other hand, the amount of Mg is 0.5
%, The recrystallized grains during brazing become fine and the high temperature buckling resistance deteriorates. In the case of brazing using a fluoride-based flux, Mg reacts with the flux to cause brazing failure. On the other hand, in the case of vacuum brazing, the evaporation amount of Mg increases and the brazing furnace is contaminated, so that the frequency of cleaning the brazing furnace becomes high and the productivity is impaired. Therefore, the amount of Mg is set within the range of 0.05 to 0.5%. On the other hand, Cu
Contributes to the strength improvement through solid solution strengthening, but if the Cu content is less than 0.05%, these effects are small, while 0.3
%, The fin material becomes noble and the sacrificial anode effect of the fin material deteriorates. Therefore Cu
The amount was in the range of 0.05 to 0.3%.

Zn, Sn, In, Ga: These elements are effective in making the potential of the fin material base and enhancing the sacrificial anode effect. Therefore, in the inventions of claims 5 to 8, among these elements, One kind or two or more kinds are added. Z
When the n content is less than 0.2%, the Sn content is less than 0.01%, the In content is less than 0.005%, and the Ga content is less than 0.005%,
The above effects are not sufficiently obtained, while the Zn content is 2.0%,
Sn amount 0.1%, In amount 0.1%, Ga amount 0.1
%, Zn content is 0.2 to 2.0% and Sn content is 0.01 to 0.01%.
0.1%, In content was 0.005-0.1%, and Ga content was 0.005-0.1%.

Fe: Fe is an element contained as an unavoidable impurity element or a positive addition element even in a normal aluminum alloy.
The Al-Mn-Fe-based coarse intermetallic compound crystallized product is formed, and the recrystallized grains during brazing become too fine, and the high temperature buckling resistance is significantly reduced. Therefore, in the case of this invention, F
It is necessary to strictly control e as an impurity to less than 0.2%.

In addition to the above elements, inevitable impurities other than Al and Fe may be used.

Next, the manufacturing process in the present invention will be described.

Fin materials for heat exchangers are generally melt-cast
By applying the process of homogenization → hot rolling → cold rolling → intermediate annealing → final cold rolling, it is manufactured as a H1n hard tempered state, that is, a product whose mechanical properties are adjusted only by work hardening. Is normal. However, it was difficult for the H1n temper to satisfy both the strength of the base plate before brazing and the high temperature buckling resistance at the same time. Therefore, in the present invention, while adjusting the component composition of the alloy as described above, at the same time as the manufacturing process, melt casting → homogenization treatment → hot rolling → cold rolling (including the case with intermediate annealing and without) → By applying the final annealing process and appropriately setting the conditions in each step, both the original plate strength and the high temperature buckling resistance could be improved. Each process will be described more specifically.

First, in the melting / casting process, a DC casting method (semi-continuous casting method) may be applied according to a conventional ordinary method.

The obtained ingot is subjected to homogenization treatment (soaking treatment). This homogenization treatment is not only for the purpose of homogenizing the structure of the ingot, but also for Al-Mn-based intermetallic compounds (Al-Mn, Al-Mn-Fe, Al-Mn-Fe).
-Si, Al-Mn-Si, etc.), Al-Zr-based intermetallic compound, and Al-Cr-based intermetallic compound are finely precipitated,
This process is necessary to make the recrystallized grains coarse during brazing, improve the high temperature buckling resistance, and increase the strength after brazing, improving the high temperature buckling resistance and the strength after brazing. For homogenization treatment at 400-550 ° C
Within the range of 1 to 30 hours. If the temperature of the homogenization treatment is less than 400 ° C, Al-Mn system, Al-Zr
Since the precipitation of the Al-Cr and Al-Cr intermetallic compounds is not sufficiently performed, the recrystallized grains during brazing are not likely to be coarse and the high temperature buckling resistance is reduced. On the other hand, if the temperature exceeds 550 ° C, Al-Mn-based, Al-Zr-based, Al-
The Cr-based intermetallic compound becomes coarse and the strength after brazing decreases, and at the same time, the recrystallized grains during brazing become fine, and the high temperature buckling resistance decreases significantly. If the homogenization time is less than 1 hour, Al-Mn-based, Al-Zr-based,
Since the precipitation of Al-Cr intermetallic compound is not sufficient, the effect of the homogenization treatment on the high temperature buckling resistance and the improvement of the strength after brazing is small. On the other hand, even if the homogenizing treatment is carried out for more than 30 hours, the above-mentioned effects are saturated, which is uneconomical in terms of energy consumption. After this homogenization treatment, hot rolling is performed as described later, but the homogenization treatment is performed in combination with heating to obtain the required hot rolling start temperature, and immediately after the homogenization treatment, hot rolling is performed. The rolling may be carried out, or after the homogenization treatment, the material may be once cooled and then heated to the hot rolling start temperature to carry out the hot rolling.

In the hot rolling after the homogenizing treatment, the starting temperature is in the range of 400 to 550 ° C. in order to obtain good hot rolling property as well as good high temperature buckling resistance and strength after brazing. Must be within. If the hot rolling start temperature is less than 400 ° C, the edge cracks during hot rolling become severe and rolling becomes difficult, while if the hot rolling start temperature exceeds 550 ° C,
The strength after brazing decreases, and the recrystallized grains after brazing become fine, so that the high temperature buckling resistance decreases. Further, the end temperature in this hot rolling needs to be 300 ° C. or lower. If the hot rolling finish temperature exceeds 300 ° C,
During cooling of the hot rolled coil after hot rolling, Al-Mn system, Al
Since -Zr-based and Al-Cr-based precipitates are deposited and coarsen, the strength after brazing is reduced and the high temperature buckling resistance is reduced.

After hot rolling, cold rolling is performed to 0.0
Although the final thickness is within the range of 3 to 0.10 mm, intermediate annealing may be performed during the cold rolling or between the hot rolling and the cold rolling. The inventions of claim 1, claim 3, claim 5, and claim 7 define the case where the intermediate annealing is not performed, and claim 2 and claim 4 specify the case where the intermediate annealing is performed. The inventions of claims 6 and 8 are:

When the intermediate annealing is performed, the material should not be completely recrystallized by the intermediate annealing.
It is necessary to anneal at temperatures below 20 ° C. If it is annealed at a high temperature of 320 ° C. or higher, recrystallization proceeds and the high temperature buckling resistance decreases. The lower limit of the intermediate annealing temperature is not particularly limited, but it is usually preferably 100 ° C. or higher in consideration of the purpose of the further intermediate annealing that facilitates cold working. Further, the holding time of the intermediate annealing is not particularly specified, but normally 0.5 hours or more and 10 hours or less is preferable. 1
Even if it is held for more than 0 hours, only softening gradually progresses, and there is no significant contribution to the improvement in high temperature buckling resistance.
Therefore, it only increases the production cost.
It is preferable that the holding time be 0 hours or less. If it is less than 0.5 hours, the cold rolling property may not be sufficiently improved. Note that this intermediate annealing may be carried out immediately by hot rolling before cold rolling as described above, or may be carried out after cold rolling to some extent and then intermediate annealing, followed by final cold rolling. good.

Cold rolling rate without intermediate annealing,
That is, the cold rolling rate from hot rolling to the final strip thickness is 90.
%, And the rolling ratio of cold rolling (final cold rolling) after intermediate annealing in the case of performing intermediate annealing needs to be 50% or more. All of them are conditions necessary for achieving a value of 200 N / mm ² or more as the strength of the base plate after the final annealing, and the cold rolling rate when the intermediate annealing is not performed is less than 90%, or the intermediate annealing is performed. If the cold rolling ratio after intermediate annealing is less than 50%, the base plate strength is 20
It becomes difficult to obtain 0 N / mm ² or more.

After finishing to the final plate thickness by cold rolling, final annealing is performed at a temperature within the range of 150 to 320 ° C. When the final annealing temperature is less than 150 ° C, the high temperature buckling resistance is not sufficiently improved, while at temperatures higher than 320 ° C, recrystallization gradually occurs and the strength of the base plate becomes lower than 200 N / mm ^2, which causes corrugation molding. In this case, defective molding of the fins and buckling of the fins at the time of assembling the heat exchanger are likely to occur, resulting in a decrease in product yield.

The fin material obtained as described above may be used as it is as a bare material in a heat exchanger, or may be clad with a brazing material during hot rolling and used as a brazing sheet by the same manufacturing method. . As a brazing method for actually assembling the heat exchanger using the fin material of the present invention, either vacuum brazing or non-oxidizing atmosphere brazing may be used.

[0034]

【Example】

Example 1: Alloy No. 1 in Table 1. 1 to No. Each alloy having the composition shown in 23 was melt-cast according to a conventional method, the obtained ingot was subjected to homogenization treatment (soaking), and hot-rolled to obtain a sheet having a thickness of 2 to 0.8 mm. A rolled plate was obtained. After that, cold rolling was performed without intermediate annealing to a plate thickness of 0.10 mm, and final annealing was performed to obtain a bare fin material. The homogenizing treatment (soaking) temperature, the hot rolling start temperature, the hot rolling finish temperature, the cold rolling rate, and the final annealing temperature in these steps are shown in Table 2 as manufacturing conditions A to I.
Shown in In all cases, except for the production condition C, the heating and holding time for the homogenization treatment was 10 hours, and the heating and holding time for the final annealing was 2 hours. In manufacturing condition C, hot rolling was performed immediately after holding at 480 ° C. for 2 hours, and the heating holding time of the final annealing was set to 2 hours.

Alloy No. of each component composition 1 to No. 23, a tensile test was performed on each fin material manufactured under any of the manufacturing conditions A to J to measure the original plate strength (tensile strength). In addition, in order to check the strength after brazing, after applying a fluoride flux to each fin material, a heat treatment equivalent to brazing at 600 ° C for 3 minutes is performed in nitrogen gas, and a tensile test is performed to perform brazing. After that, the corresponding tensile strength was measured.

Further, the pitting corrosion potential of each fin material was examined in order to evaluate the corrosion resistance as a heat exchanger, particularly the sacrificial anode effect of the fin material. That is, in general, the fin material is brazed to a tube or core plate for circulating a temperature medium (working fluid) to exert a sacrificial anode effect on the tube or core plate to protect the tube or core plate from corrosion. In order to exert the sacrificial anode effect of the fin material in that case, it is necessary that the pitting corrosion potential of the fin material is 30 mV or more base with respect to the tube and the core plate.
And as a tube or fin material for heat exchangers,
The 3004 alloy and the Al-Mn-Cu (-Ti) alloy containing 0.2 to 0.8% of Cu are used, but the former 3003 alloy has a pitting corrosion potential of about-after brazing. 700 mV, -660 m for the latter Al-Mn-Cu (-Ti) -based alloy containing 0.2 to 0.8% Cu.
It is about V, and in order to exert a sufficient sacrificial anode effect by the fin material against any of these, it is necessary that the pitting corrosion potential of the fin material is −730 mV or more. Therefore, in this embodiment, the pitting potential of the fin material is −
The corrosion resistance as a heat exchanger can be evaluated depending on whether it is 730 mV or more base. The measurement of pitting potential is
It was carried out in a 2.67% AlCl ₃ aqueous solution.

Further, in order to evaluate the high temperature buckling resistance during brazing, the sag amount under the condition corresponding to brazing of the fin material was examined. That is, a sample is cut into a width of 20 mm and a length of 70 mm, a fluoride-based flux is applied, one end of the sample is fixed with a jig, and it is horizontally projected to a length of 60 mm, and the temperature is 600 ° C. for 3 minutes in a nitrogen gas atmosphere. Was heated, and the amount of sag of the protruding tip was measured.

Further, the fin material is corrugated and a fluoride-based flux is applied to it, and a 3003 alloy is used as a core material and a 4045 alloy is used as a brazing material.
After brazing and heating in a nitrogen gas atmosphere at 600 ° C for 3 minutes, the observing of the brazing condition is carried out microscopically and the erosion of the fin material by the molten brazing during brazing is performed. I checked.

Table 3 shows the results of each of the above surveys.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

From Table 3, in the fin material (example of the present invention) obtained by satisfying the component composition conditions and manufacturing process conditions specified in the present invention, the strength of the base plate is 200 N / mm of the target strength.
Greatly exceeds ² and the strength after brazing is 100N
/ Mm ² and the sag amount is 10 mm or less, the high temperature buckling resistance is excellent, and the natural potential is certainly less than -730 mV and has a sufficient sacrificial anode effect, and heat exchange. It was found that it has excellent corrosion resistance as a container and that there is almost no erosion of the brazing material during brazing. On the other hand, in Comparative Examples in which either the component composition condition or the manufacturing process condition was out of the range defined by the present invention, any one of the above performances was inferior.

Example 2: As in Example 1, N in Table 1
o. 1 to No. For each alloy having the composition shown in 23,
Melt casting according to a conventional method, homogenization treatment (soaking treatment) is performed on the obtained ingot, and hot rolling is performed to obtain a thickness of 2.
It was a 0 mm hot rolled plate. After that, cold rolling was performed, intermediate annealing was performed, and then final cold rolling was performed to a plate thickness of 0.07 mm, and final annealing was performed to obtain a bare fin material. The temperature of homogenization treatment in these processes,
The manufacturing conditions K to W in Table 4 show the hot rolling start temperature, the hot rolling end temperature, the plate thickness during intermediate annealing, the intermediate annealing temperature, the final cold rolling reduction, and the final annealing temperature. In all cases, except for the manufacturing condition M, the heating and holding time for the homogenization treatment was 1
The heating and holding time for the intermediate annealing was 5 hours, and the heating and holding time for the final annealing was 2 hours. 480 ° C under manufacturing condition M
After holding for 2 hours, hot rolling was performed immediately. In addition, the holding time of the intermediate annealing and the final annealing in that case was set to 5 hours.

Alloy No. of each component composition 1 to No. Table 5 and Table 6 show the results of examining various performances of No. 23 for each fin material manufactured under any of the manufacturing conditions K to W in the same manner as in Example 1 above.

[0046]

[Table 4]

[0047]

[Table 5]

[0048]

[Table 6]

As shown in Tables 5 and 6, in the case of Example 2, since the final plate thickness is smaller than that in Example 1, the sag amount is generally large. It is apparent that the sag amount of the invention example is smaller than that of the comparative example and the high temperature buckling resistance is excellent. The other properties of the fin material according to the example of the present invention were excellent as in the case of Example 1 shown in Table 3.

Example 3: Alloy No. 1 in Table 1 For the alloy having the composition shown in Table 2, a bare fin material having a plate thickness of 0.07 mm was manufactured according to the method of Example 1 under the conditions of manufacturing condition code B shown in Table 2 (however, the cold rolling ratio was Unlike the case of the condition code B, 93%). Similarly, alloy No. 1 in Table 1 is used. A bare fin material having a plate thickness of 0.07 mm was manufactured according to the method of Example 2 under the manufacturing condition L shown in Table 4 for the alloy having the component composition shown in Table 9.

For each fin material, a tensile test is carried out to measure the strength of the base plate (tensile strength), and in order to examine the strength after vacuum brazing, 600 ° C. × 3 minutes in a vacuum of 5 × 10 ⁻⁵ Torr. The heat treatment corresponding to the vacuum brazing was performed, and the tensile strength after vacuum brazing was measured by a tensile test. Further, in order to evaluate the corrosion resistance as a heat exchanger, particularly the sacrificial anode effect of the fin material, the pitting corrosion potential of each fin material was measured in the same manner as in Example 1. In addition, in order to evaluate the high temperature buckling resistance in vacuum brazing, a sample of the fin material is cut into a width of 20 mm and a length of 70 mm, one end of which is fixed by a jig and horizontally projected to a length of 60 mm, 600 ° C × in a furnace with a vacuum degree of 5 × 50 ^-5 Torr
After heating for 3 minutes, the amount of sag of the protruding tip was measured. Further, the fin material was corrugated and placed on a brazing sheet using 3003 alloy as a core material and 4104 alloy as a brazing material, and then 5 × 10 ⁻⁵
After brazing and heating at 600 ° C. for 3 minutes in a vacuum atmosphere of Torr, the brazing condition was microscopically observed to examine the erosion property of the fin material by the molten brazing during vacuum brazing. Table 7 shows the results of each of these investigations.

[0052]

[Table 7]

As can be seen from Table 7, in the case of Example 3 in which vacuum brazing was performed, the fin material having the same plate thickness was brazed in a nitrogen gas atmosphere using fluoride flux (Example 2). The result is almost the same.

[0054]

As is apparent from the above-described embodiments, the fin material for the heat exchanger obtained by the method of the present invention has a high strength before brazing (base plate strength) and a plate thickness of 0.1 mm.
Even if it is thin as below, it will be deformed during heat exchanger assembly,
It is extremely unlikely to buckle, has excellent high temperature buckling resistance, and is unlikely to buckle due to the high temperature during brazing. In addition, the fin material obtained by the method of the present invention has a high strength after brazing, and also has a sufficient sacrificial anode effect on these tubes and core plates after brazing with the core plates and tubes as a heat exchanger. It can be demonstrated and has very little erosion due to brazing material. Therefore, if the fin material obtained by the method of the present invention is used for a heat exchanger, the fin material can be actually thinned to 0.1 mm or less without impairing the various performances required for the fin material and the heat exchanger itself. It is possible to reduce the weight and cost of the heat exchanger.

Claims (8)

[Claims] 1. Mn 1.0-2.0% (weight%, the same hereinafter), Si 0.2-0.8% are contained, and Zr0.
Of alloys containing one or two of 0.03 to 0.3% and 0.03 to 0.3% Cr, Fe regulated to less than 0.2%, and the balance being Al and inevitable impurities. The ingot is homogenized at 400 to 550 ° C. for 1 to 30 hours, and when hot rolling is performed, the hot rolling start temperature is set to 400 to 550 ° C. and the hot rolling end temperature is 300 ° C. or less. After the hot rolling is completed, cold rolling is performed at a cold rolling rate of 90% or more to 0.03 to 0.10.
Cold rolled sheet having a thickness within the range of mm, and further 150 to 32
Final annealing at a temperature in the range of 0 ° C gives a tensile strength of 2
A method for producing a high-strength, high-heat-resistant fin material made of an aluminum alloy for a heat exchanger, which comprises obtaining a fin material of 00 N / mm ² or more. 2. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
It contains one or two of r0.03 to 0.3%, Fe is regulated to less than 0.2%, and the balance is Al.
And 40 for ingots of alloys consisting of unavoidable impurities
The homogenizing treatment is performed at 0 to 550 ° C. for 1 to 30 hours, and when hot rolling is further performed, the hot rolling start temperature is set to 400.
~ 550 ° C and the hot rolling end temperature is 300 ° C
After the completion of hot rolling, cold rolling is performed or without cold rolling, intermediate annealing is performed at a temperature of less than 320 ° C., and cold rolling is performed at a cold rolling rate of more than 50%. A cold-rolled sheet having a thickness within the range of 0.03 to 0.10 mm and further subjected to final annealing at a temperature within the range of 150 to 320 ° C. to obtain a fin material having a tensile strength of 200 N / mm ² or more. A method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger, the method comprising: 3. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r0.03 to 0.3%, Mg0.05 to 0.5%, Cu0.05 to
It contains one or two of 0.3%, and Fe
Is regulated to less than 0.2%, and the balance is subjected to homogenization treatment at 400 to 550 ° C. for 1 to 30 hours on an ingot of an alloy composed of Al and unavoidable impurities, and when hot rolling is performed, heat treatment is performed. The hot rolling start temperature is set to 400 to 550 ° C., the hot rolling end temperature is set to 300 ° C. or less, and cold rolling is performed at a cold rolling rate of 90% or more after the hot rolling is finished to 0.03 to 0.10 mm. Cold-rolled sheet having a plate thickness within the range of, and further subjected to final annealing at a temperature within the range of 150 to 320 ° C. to obtain a fin material having a tensile strength of 200 N / mm ² or more. A method for manufacturing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a exchanger. 4. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r0.03 to 0.3%, Mg0.05 to 0.5%, Cu0.05 to
It contains one or two of 0.3%, and Fe
Is regulated to less than 0.2%, and the balance is subjected to homogenization treatment at 400 to 550 ° C. for 1 to 30 hours on an ingot of an alloy composed of Al and unavoidable impurities, and when hot rolling is performed, heat treatment is performed. The hot rolling start temperature is set to 400 to 550 ° C., the hot rolling end temperature is set to 300 ° C. or less, and after the hot rolling is completed, cold annealing is performed or not, and the intermediate annealing is performed at 320 ° C. or less. And further 50%
Cold rolling at a cold rolling ratio exceeding 0.03
Cold rolled plate with a thickness within the range of 0.10 mm, and further 15
A high strength and high heat resistance fin material made of aluminum alloy for heat exchanger, characterized by obtaining a fin material having a tensile strength of 200 N / mm ² or more by performing final annealing at a temperature in the range of 0 to 320 ° C. Production method. 5. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r 0.03 to 0.3%, Zn 0.2 to 2.0%, Sn 0.01 to
0.1%, In 0.005-0.1%, Ga 0.005
To 0.1%, one or more of them are contained, Fe is regulated to less than 0.2%, and the balance is 400 to 55 with respect to the ingot of the alloy consisting of Al and unavoidable impurities.
When homogenizing treatment is performed at 0 ° C. for 1 to 30 hours and hot rolling is further performed, the hot rolling start temperature is 400 to 550.
C. and the hot rolling finish temperature is 300 ° C. or lower, and after the hot rolling is finished, cold rolling is performed at a cold rolling rate of 90% or more to cool the plate thickness within a range of 0.03 to 0.10 mm. Aluminum alloy for heat exchanger, which has a high strength and a high strength and is characterized in that it is a rolled sheet and further subjected to final annealing at a temperature in the range of 150 to 320 ° C. to obtain a fin material having a tensile strength of 200 N / mm ² or more. Method for manufacturing heat-resistant fin material. 6. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r 0.03 to 0.3%, Zn 0.2 to 2.0%, Sn 0.01 to
0.1%, In 0.005-0.1%, Ga 0.005
To 0.1%, one or more of them are contained, Fe is regulated to less than 0.2%, and the balance is 400 to 55 with respect to the ingot of the alloy consisting of Al and unavoidable impurities.
When homogenizing treatment is performed at 0 ° C. for 1 to 30 hours and hot rolling is further performed, the hot rolling start temperature is 400 to 550.
C. and the hot rolling finish temperature is 300.degree. C. or less, and after the hot rolling is finished, cold rolling is performed or without cold rolling, intermediate annealing is performed at less than 320.degree. C., and further exceeds 50%. Cold rolling was performed at a cold rolling rate of 0.
A cold-rolled sheet having a thickness within the range of 03 to 0.10 mm and further subjected to final annealing at a temperature within the range of 150 to 320 ° C. to obtain a fin material having a tensile strength of 200 N / mm ² or more. A method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger, which is characterized. 7. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r0.03 to 0.3%, Mg0.05 to 0.5%, Cu0.05 to
1% or 2% of 0.3% and Zn
0.2-2.0%, Sn0.01-0.1%, In0.
Alloy containing 005 to 0.1% and one or more of 0.005 to 0.1% Ga, Fe regulated to less than 0.2%, and balance Al and unavoidable impurities In the case of performing homogenization treatment at 400 to 550 ° C. for 1 to 30 hours on the ingot, and further performing hot rolling,
After the hot rolling start temperature is set to 400 to 550 ° C. and the hot rolling end temperature is set to 300 ° C. or less, 9
Cold rolling is performed at a cold rolling ratio of 0% or more to 0.03 to
Cold rolled plate with a thickness within the range of 0.10 mm, and further 15
A high strength and high heat resistance fin material made of aluminum alloy for heat exchanger, characterized by obtaining a fin material having a tensile strength of 200 N / mm ² or more by performing final annealing at a temperature in the range of 0 to 320 ° C. Production method. 8. Mn 1.0 to 2.0%, Si 0.2 to
0.8%, Zr 0.03-0.3%, C
In addition to containing one or two of r0.03 to 0.3%, Mg0.05 to 0.5%, Cu0.05 to
1% or 2% of 0.3% and Zn
0.2-2.0%, Sn0.01-0.1%, In0.
Alloy containing 005 to 0.1% and one or more of 0.005 to 0.1% Ga, Fe regulated to less than 0.2%, and balance Al and unavoidable impurities In the case of performing homogenization treatment at 400 to 550 ° C. for 1 to 30 hours on the ingot, and further performing hot rolling,
The hot rolling start temperature is set to 400 to 550 ° C., the hot rolling end temperature is set to 300 ° C. or less, and after the hot rolling is finished, cold rolling is performed or not, 32
Intermediate annealing is performed at a temperature of less than 0 ° C, and cold rolling is performed at a cold rolling rate of more than 50% to obtain a cold-rolled sheet having a plate thickness in the range of 0.03 to 0.10 mm, and further 150 to 320 ° C. Final annealing at a temperature within the range, tensile strength of 200N
A method for producing a high-strength and high-heat-resistant fin material made of an aluminum alloy for a heat exchanger, which comprises obtaining a fin material having a thickness of at least 1 / mm ² .