JPS63162833A - Al-alloy brazing sheet for heat exchanger molding high strength after brazing - Google Patents

Abstract

PURPOSE:To maintain high strength after brazing, by cladding a core material of Al alloy containing, as principal components, specific amounts of Zn, Mg, and Si with a cladding material of Al-Si or Al-Si-Mg alloy. CONSTITUTION:The Al alloy which has a composition consisting of, by weight, 3.2-4.5% Zn, 0.2-1.2% Mg, 0.2-1% Mn, 0.35-1% Si, and the balance Al with inevitable impurities and containing, if necessary, 0.1-0.5% Cr and/or 0.03-0.2% Zr, 0.01-0.2% Ti, and 0.03-0.4% Cu is used as core material. One side or both sides of this core material are clad with a brazing filler metal of Al-Si or Al-Si-Mg alloy as cladding material so as to be formed into an Al-alloy brazing sheet for heat exchanger. Since the high strength before brazing can be maintained even after brazing owing to the above method, this alloy can be used in a thin-walled condition for manufacturing heat exchangers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an M alloy brazing sheet for heat exchangers that maintains high strength even after brazing.

[Conventional technology]

Conventionally, in general, 1, for example, radiators of motorcycles and automobiles, condensers of coolers, and evaporators, etc., are collectively referred to as C.

For example, JIS/7NOL is used as a fin material and tube material for manufacturing heat exchangers.

With a heavy position (hereinafter, ``chi'' refers to a ``superior position'').

Zn: 4~5'Ir, Mg: l~2%
.

Mn: 0.2-0.7%.

An M-Si alloy having a normal composition of M-S1 is used as a core material and a skin material on one or both sides of this core material. - M made by cladding Mg alloy brazing filler metal
Alloy brazing sheets are used.

[Problem that the invention seeks to solve]

Vacuum brazing and flux brazing are essential for manufacturing the heat exchanger described in this article.1. In the conventional M alloy brazing sheet shown in E, there are scattered parts that melted during brazing. In order to prevent so-called burning from occurring, Zn and Mg1t in the core material must be kept low, resulting in a decrease in strength after brazing, making it impossible to ensure high strength after brazing. , the wall thickness is increased to compensate for the decrease in strength, which goes against the growing demand for transophthalmology and labor saving in recent years.

[Means for solving problems]

Therefore, the inventors of the present invention, etc., have the following points of view.

When ordering a heat exchanger, we conducted research to develop an M alloy brazing sheet that maintains high strength even after brazing, and as a result we developed a core material.

Zn: 3.2 to 4.5%, m: o, z to i, 21
°Mn: 0.2-1%, Si: 0.35-1
%.

Contains and further if necessary.

Cr: O, 1-0.5%, Zr: 0.03-0.2
blood.

Ti: 0. Ol ~0.2%, Cu: 0.03~0
．． 4%.

eA4 is composed of an M alloy having a composition containing Ti or two or more of the above, and the remainder consisting of Al and unavoidable impurities.
In alloy brazing sheets, there is no decrease in strength after brazing, and the high strength before brazing is maintained even after brazing, so it is possible to reduce the thickness of the sheet and make it possible to use it over time. I gained knowledge.

This invention was made based on the above findings.

Zn: 3.2-4.5%, Mg: 0.2-1.
2%.

Mn: 0.2-1%, Si: 0.35-1%
.

Contains and further if necessary.

Cr: O, 1-0.5%, Zr: 0.03-0.2
q6゜Ti: 0.01-0.2%, Cu: 0.0
3-0.4%.

A core material is an M alloy having a composition containing one or more of the following, with the remainder consisting of Al and unavoidable impurities, and on one or both sides of this core material, a JIS-BA
It is clad with a brazing filler metal having the usual composition of M-Si alloys such as 4343 and 4045, or M-Si-alloys such as BA4004.

This M alloy brazing sheet for heat exchangers maintains high strength after brazing.

Next, the reason why the composition of the core material of the M alloy brazing sheet of the present invention is limited as described above will be explained below.

(a) Zn Zn53E component not only improves strength when coexisting with Mg component, but also increases deformation resistance during rolling.

This promotes the formation of a large number of lattice defects, thereby increasing the A41t -Mn-
It has the effect of promoting the precipitation of fine intermetallic compounds of Si during brazing, but if the content is less than 3.2 Ti, the desired effect cannot be obtained; Beyond this point, workability deteriorates and there are scattered areas that melt during brazing. Since it causes so-called burning, its content should be reduced to 3.
It was set at 2 to 4.5 inches.

(b) Mg Mg5SiE has the effect of improving strength in coexistence with Zn as described above, but when its content is 0.2
If it is less than 1, the desired strength cannot be secured.

On the other hand, if the acid content exceeds 1.2%, not only will processability deteriorate, but also burning will occur, and the fluidity of the wax will also be impaired. was set at 0.2% to 1.2%.

(c) ]VInMn532 maintains a crystal grain lamellar structure flat in the pre-processed direction before and after brazing.

It has the effect of suppressing strength loss after brazing, but
If the acid content is less than 0.2%, the desired effect cannot be obtained, while if the acid content exceeds 1%, processability will be inhibited. ~1
%.

(dl 5i The Si component precipitates fine intermetallic compounds (AA-Mn-Si) during brazing, maintains high strength even at high temperatures during brazing, and maintains high strength after brazing. It has the effect of improving strength, but if the content is less than 0.35 inch, the desired effect cannot be obtained;
If i exceeds L%, workability will deteriorate, so the content l was determined to be 0.35 to l. Further, when the content ratio is Mn/Si:1 or more, even higher strength can be obtained.

(e) Cr and Zr These components include: In coexistence with the Mn component.

A lamellar structure with flat grains in the pre-processed direction.

It retains its strength before and after brazing, thereby further suppressing the decrease in strength after brazing.

It is included as necessary when even higher strength is required, but if the content is less than 0.1% Cr and less than 0.03% Zr, the desired strength improvement cannot be achieved after brazing. On the other hand, the acid content is Cr
: 0.5% and Zr: If it exceeds 0.2%, processability will be inhibited.
: O, 1-0.5%, Zr: 0.03-0.
It was set at 2%.

ge) Ti For the TiE component, the crystal grains during casting are made uniform and fine.

Coupled with the effects of Mn*Cr+ and Zr,
It has the effect of further improving the strength after brazing.

It is included as necessary when even higher strength is required, but if the acid content is less than O. The acid content was determined to be 0.01-0.2% because the processability was inhibited.

(g) Cu Cu53E has the effect of solidly dissolving in the base material and further improving its strength, so it is included as necessary when crystal strength is required, but if the acid content is 0. .03%
If the acid content is less than 0.4%, the desired strength improvement effect cannot be obtained, and on the other hand, if the acid content exceeds 0.4%, cracks are likely to occur in the burning area.
It was determined that

〔Example〕

Next, the M alloy brazing sheet of the present invention will be specifically explained using examples.

Molten M alloys for the core material having the component compositions shown in Table 1 were prepared, and using an experimental semi-continuous casting apparatus, 45
An ingot with a cross-sectional dimension of m x 190 ms was made, and after homogenizing and facing under normal conditions, it was hot-rolled to form a hot-rolled plate for core material with a thickness of 9 mm. As an M alloy for brazing filler metal.

M alloy (hereinafter referred to as A alloy) containing Group 53E (BA4045) containing Si: 9.7% and the remainder consisting of Al and unavoidable impurities, and Si: 9.6%, Mg
: M alloy (BA4004) containing 1.6% and the remainder consisting of Al and unavoidable impurities
An ingot of the alloy (referred to as alloy) is prepared, and it is homogenized and solidified under normal conditions, and then hot-rolled and cold-rolled to form a cold-rolled plate for brazing filler metal with a thickness of l. Then, the core material hot-rolled sheet and the brazing material cold-rolled sheet are stacked one on top of the other, and then hot-rolled and cold-rolled under normal conditions, and then clad to a thickness of 1.51. M alloy brazing sheet of the present invention 1 to 23° Comparison M alloy brazing sheet)
1-4. and conventional M alloy brazing sheets corresponding to JIS 7NO1 were manufactured.

In addition, comparative M alloy brazing sea) 1 to 4 are.

All of them have compositions in which one of the components contained in Structure 11i3E51 (marked with * in Table 1) is outside the scope of the present invention.

Also, any M alloy brazing sheet.

As unavoidable impurities, Cr: 0.01 or less, Zr: 0
．． 0.01% or less, Ti: 0.005% or less, and Cu:
It contained 0.01% or less.

Next, the various M alloy brazing sheets obtained as a result were subjected to a solution treatment of water cooling after being held at a temperature of 500°C for 2 hours, and then an aging treatment of being held at a temperature of 150°C for 8 hours. The tensile strength is measured by , and is also equivalent to vacuum brazing. In vacuum, @ll': 610℃
Brazing heating was performed for 5 minutes, and the tensile strength was measured after 14 days had elapsed. The results of these measurements are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, it is clear that the conventional M alloy brazing sheets cannot maintain the high strength before brazing even after brazing, whereas the M alloy brazing sheets 1 to 23 of the present invention cannot maintain the high strength before brazing even after brazing. It is clear that the high strength before brazing is maintained even after brazing.

In addition, as seen in Comparative M Alloy Brazing Sea) 1 to 4, even if the component content l of the structure 5SiE53E falls outside the scope of this invention, it is not possible to ensure forced inspection after brazing. it is obvious.

As mentioned above, the M alloy brazing sheet of the present invention maintains the high strength and strength before brazing even after brazing, so it can be used in the production of heat exchangers in a thin-walled state. It is a great contribution to light Europeanization.

Claims (8)

[Claims] (1) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2-1%, Si: 0.35-1%, and the remainder is Al and unavoidable impurities. Al-Si alloy or Al-S as skin material on one or both sides of the material
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding an i-Mg alloy brazing material. (2) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2-1%, Si: 0.35-1%, and further contains Cr: 0.1-0.5%, Zr: 0.03-0.2%,
An Al alloy containing one or two of the above and the remainder consisting of Al and unavoidable impurities (wt%) is used as a core material, and one or both sides of this core material is coated with Al as a skin material.
- An Al alloy brazing sheet for a heat exchanger that maintains high strength after brazing and is made by cladding a brazing material of Si alloy or Al-Si-Mg alloy. (3) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2 to 1%, Si: 0.35 to 1%, and further contains Ti: 0.01 to 0.2%, with the remainder consisting of Al and inevitable impurities. An Al alloy having the following composition (weight%) is used as a core material, and an Al-Si alloy or an Al-Si alloy or an Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material. (4) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2 to 1%, Si: 0.35 to 1%, and further contains Cu: 0.03 to 0.4%, with the remainder consisting of Al and inevitable impurities. (wt%) is used as a core material, and on one or both sides of this core material, an Al-Si alloy or an Al-Si alloy or an Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material. (5) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2-1%, Si: 0.35-1%, and further contains Cr: 0.1-0.5%, Zr: 0.03-0.2%,
The core material is an Al alloy containing one or two of the above, Ti: 0.01 to 0.2%, and the remainder consisting of Al and unavoidable impurities (weight %). Al-Si alloy or Al-Si alloy or Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material. (6) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2-1%, Si: 0.35-1%, and further contains Cr: 0.1-0.5%, Zr: 0.03-0.2%,
The core material is an Al alloy containing one or two of the above, Cu: 0.03 to 0.4%, and the remainder consisting of Al and unavoidable impurities (weight percent). Al-Si alloy or Al-Si alloy or Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material. (7) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn: 0.2-1%, Si: 0.35-1%, and further contains Ti: 0.01-0.2%, Cu: 0.03-0.4%. The core material is an Al alloy having a composition (by weight %) of which the remainder consists of Al and unavoidable impurities, and an Al-Si alloy or an Al-Si alloy or Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material. (8) Zn: 3.2-4.5%, Mg: 0.2-1.
2%, Mn. 0.2-1%, Si: 0.35-1%, and further contains Cr: 0.1-0.5%, Zr: 0.03-0.2%,
A composition containing one or two of the above, Ti: 0.01 to 0.2%, and Cu: 0.03 to 0.4%, with the remainder consisting of Al and unavoidable impurities (more than 1% by weight). ) is used as a core material, and on one or both sides of this core material, an Al-Si alloy or an Al-
An Al alloy brazing sheet for heat exchangers that maintains high strength after brazing and is made by cladding a Si-Mg alloy brazing material.