JPS585255B2 - Fin material for heat exchanger and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fin material for a heat exchanger and a method for manufacturing the same.

The heat exchanger consists of members that constitute working fluid passages and cooling fins, and is assembled by flux brazing, fluffless brazing in an inert atmosphere, vacuum brazing, etc. car air conditioner (
For aluminum heat exchangers such as evaporators, condensers), radiators, and oil coolers,
AA1050 (Al≧99.5%), A as fin material
A3003 (Al-1,2%Mn), AA7072 (A
A thin plate such as 1-1.2% Zn) or a thin plate obtained by cladding the thin plate with a brazing material is used.

However, since the above-mentioned alloy for fin material has poor high-temperature sag properties, there is a problem in that the fin material buckles and deforms during assembly when brazing a heat exchanger.

Further, in a heat exchanger assembled using a fin material made of the above-mentioned alloy, there is a problem in that pitting corrosion occurs from the outside (fin side) in the aluminum material that constitutes the working fluid passage during use.

This invention provides an aluminum alloy fin material for heat exchangers that solves the above problems, and its gist is that Mn 0.3-1.3%, Zn 0.5-3.5%
, Fe 0.3-1.3% (however, Mn≧Fe), Mg0
．． 03-0.55%, Cr 0.01-0.1%, Cu
A heat exchanger fin material containing 0.01 to 0.2% and the remainder Al and impurities, and the above alloy ingot were mixed into 45
The method of manufacturing a fin material for a heat exchanger includes a step of hot rolling at 0 to 550°C to a thickness of 2 to 5 mm, and a final cold rolling at a reduction rate of 60% or less.

The fin material of the present invention does not buckle when brazed, has a sacrificial anode effect, and provides corrosion protection to the material forming the fluid passages of the heat exchanger.

Reasons for limiting alloy components Mn: Improves the strength of the fin material and helps improve sag resistance.

If it is less than 0.3%, these effects will not be sufficient;
If it exceeds 3%, a giant compound is formed, making casting and processing difficult, and the sacrificial anode effect decreases.

Zn: Gives the fin material a sacrificial anode effect.

If it is less than 0.5%, this effect will be small, and if it exceeds 3.5%, self-corrosion will become significant.

Fe: Improves the strength of the fin material and improves the formability and sag resistance of the fin material.

If it is less than 0.3%, these effects will not be sufficient;
If it exceeds 3%, giant compounds are formed and processability is impaired.

The purpose of setting Mn≧Fe is to reduce the formation of Al-Fe-Mn-based compounds and prevent deterioration of workability.

Mg, Cr and Cu: Improves the formability and sag resistance of the fin material without deteriorating the sacrificial anode effect.

Mg, Cr and Cu are 0.3% and 0.01% respectively
If the amount of Mg is less than 0.01%, the performance improvement effect is small.

When Cr and Cu exceed 0.55%, 0.1% and 0.27%, respectively, the grain size becomes small, sag resistance and formability are reduced, and the sacrificial anode effect is also reduced.

45 aluminum alloy ingots containing the above alloy components
Hot rolling is carried out at 0 to 550° C. to a thickness of 2 to 5 mm, and the final cold rolling is carried out at a rolling reduction of 60 mm or less.

When the fin material manufactured through this manufacturing process is combined with other aluminum materials constituting the working fluid passage and a heat exchanger is manufactured by brazing, the grain size after brazing is 60μ or more, and it is excellent. It has excellent sag resistance.

The alloy of the present invention may be used as a fin material as it is, or may be used as a plating sheet/fin material clad with an A1 alloy brazing filler metal containing 6 to 14% Si.

Table 1 shows the composition of the fin material of the present invention, and Table 2 shows the formability and sag resistance of the fin material having the composition shown in Table 1.

Further, the fluid passage forming material of a heat exchanger manufactured by brazing using an alloy having the composition shown in Table 1 as the fin material and using AA3003 (Al-1,2%Mn) as the fluid passage forming material. Table 3 shows the degree of corrosion from the outside (fin side).

As shown in Table 2, the invention alloy has excellent formability as a fin material, has a small drooping amount, and has excellent sag resistance.

Further, as shown in Table 3, the invention alloy has a sacrificial anode effect and provides a corrosion-preventing effect to the material constituting the working fluid passage.

Next, Al-6 to 14
%5i-0,3~3%Mg alloy brazing filler metal, Al-6~14
0.01-0.5% Bi in the %Si alloy.

0.01-0.5% Sb, 0.01-0.5% Ba.

0.01~0.5%Sr, 0.0002~0.1%Be
Aluminum alloy brazing filler metal containing one or more of
and Al-6~14%5i-0,3~3%Mg alloy with 0.01~0.5%Bi, 0.01~0.5%Sb, 0
．． 01-0.5% Ba, 0.01-0.5% Sr.

Cladding aluminum alloy brazing filler metal containing one or more of 0.0002 to 0.1% Be (clad ratio 10
When a plating sheet with a thickness of 1.6 mm (~12%) was prepared and the tests shown in Tables 2 and 3 were conducted, the formability was good in all cases, and the amount of droop was 0.5~12%.
6mm, maximum pit depth in salt spray test is 0.0
2 to 0.09 mm, and the maximum pit depth in the wet and dry alternating test was 0.04 to 0.12 mm, with excellent formability.
It showed sag resistance and anticorrosion effect.

[Brief explanation of drawings]

FIG. 1 is a side view schematically showing an apparatus for measuring sag resistance. 1 is a holding jig, and S is a test fin material.

Claims (1)

[Claims] 1 Mn 0.3-1.3%, Zn 0.5-3.
5%, Fe0.3-1.3% (however, Mn≧Fe), Mg
0.03-0.55%, Cr0.01-0.1%, Cu
A fin material for a heat exchanger containing 0.01 to 0.2%, with the remainder consisting of Al and impurities. 2 Mn 0.3-1.3%, Zn 0.5-3.
5%, Fe0.3-1.3% (however, Mn≧Fe), Mg
0.03-0.55%, Cr 0.01-0.1%,
An aluminum alloy ingot containing 0.01 to 0.2% of Cu and the remainder consisting of Al and impurities was prepared at 450 to 550
Hot rolling process at ℃ to a thickness of 2 to 5 mm, rolling reduction rate of 60
A method for producing a fin material for a heat exchanger, which includes a final cold rolling process at a temperature of % or less.