WO2014141912A1 - Aluminum alloy plate for fabrication, method for producing same, and aluminum alloy brazing sheet - Google Patents

Abstract

The present invention provides an aluminum alloy plate that is for fabrication, has superior moldability, brazability, and post-brazing strength, is favorably used as a heat exchanger, and is characterized by resulting from hot rolling and cold rolling an aluminum alloy ingot having a composition containing 1.2-2.0% of Mn, 0.5-1.0% of Si, 0.10-0.20% of Ti, and V as an impurity restricted to no greater than 80 ppm, the remainder comprising Al and unavoidable impurities, having no greater than 1/m³ of coarse intermetallic compounds having a generated size (circular equivalent diameter) of at least 4 mm, and having no greater than 10/m³ of intermetallic compounds that are at least 1 mm and less than 4 mm.

Description

Aluminum alloy plate for forming process, method for producing the same, and aluminum alloy brazing sheet

The present invention is excellent in formability, brazeability and strength after brazing, and is particularly suitable for use in heat exchangers such as radiators, car heaters, car air conditioners, etc. The present invention relates to an aluminum alloy brazing sheet having an aluminum alloy plate as a core material.

An aluminum alloy containing a large amount of Mn is light and excellent in workability, so it is often used as a material for heat exchangers, beverage containers, and battery cases. Among these, as a heat exchanger material, a brazing sheet in which a brazing material is clad on a 3003 alloy plate and a 3003 alloy is used.

In recent years, especially the weight reduction of the heat exchanger for automobiles has been demanded, and in order to further reduce the weight of the heat exchanger, the strength after brazing has been improved by increasing the Mn content in the aluminum alloy. ing. Further, since the penetration life due to corrosion decreases when the material becomes thin, the corrosion life is also improved by adding Ti to the 3003 alloy to make the progress of corrosion laterally spread.

Various heat exchangers such as a drone cup type and a parallel flow type are used as the heat exchanger. Delon cup type heat exchanger is composed by laminating a plurality of plates, forming a grooved body part in the middle part by press working, and laminating plates with cylindrical parts on both sides alternately Then, the tube is formed by combining the body portions, the cylindrical portions are connected to form tanks at both ends, and fins are provided between the body portions adjacent to each other in the stacking direction. Is.

The parallel flow type heat exchanger has a plurality of flat tubes stacked on each other, and a pair of tank portions connected to both ends in the longitudinal direction of the flat tubes and communicating with each other through the flat tubes. The part has a structure in which a plate header in which a tube insertion hole into which a flat tube is inserted is formed, a tank header combined with the plate header, and an intermediate plate interposed between the plate header and the tank header are integrated by brazing It has.

As flat tubes, extruded porous tubes and brazing sheets are formed into round shapes, welded flat tubes that are deformed into flat shapes after joining the ends by high-frequency welding, and the brazing sheets are bent into flat shapes, There is a brazed flat tube formed integrally with other members by brazing heating. Holes and tank shapes into which flat tubes are inserted are formed in the plate header and the tank header by pressing.

In an Al—Mn alloy plate used in such a heat exchanger, when the Mn content is increased for improving the strength and Ti is added for improving the corrosion resistance, Ti becomes a metal such as Al ₆ Mn. It tends to be an intermetallic compound nucleus, and a coarse intermetallic compound is easily generated in an aluminum alloy during casting of the material. When such a coarse intermetallic compound is formed, it remains in the plate material without being divided even if processing such as homogenization treatment or hot rolling is performed thereafter, and it becomes the starting point of the plate material and brazing sheet. There is a problem that breakage and cracking occur during the molding process.

As a method of suppressing the formation of coarse intermetallic compounds, there is a method of increasing the cooling rate at the time of casting like molten metal rolling, but there is a problem in characteristics that the surface quality of the plate material is inferior, Since the structure is complicated, there is a drawback that a large amount of casting equipment costs are required.

JP 2002-155332 A JP 2002-161323 A JP 2002-180171 A

As a result of repeated tests and examinations in order to solve the above-described problems in the Al—Mn alloy plates for heat exchangers, the inventors have found inevitable impurities in aluminum alloys in DC (Direct Chill) casting. By finding that V is involved in the formation of coarse intermetallic compounds, by regulating the V content, the Mn content is high, and the intermetallic compounds produced in the Al-Mn alloy plates containing Ti are suppressed. Found that you can.

The present invention has been made on the basis of the above findings, and its purpose is excellent in moldability, brazing performance and strength after brazing, and is particularly suitable for heat exchangers such as radiators, car heaters, and car air conditioners. An object of the present invention is to provide an aluminum alloy plate for forming and a manufacturing method thereof, and an aluminum alloy brazing sheet using the aluminum alloy plate as a core material.

In order to achieve the above object, an aluminum alloy sheet for forming according to claim 1 has Mn: 1.2 to 2.0%, Si: 0.5 to 1.0%, Ti: 0.10 to 0.00. Coarse intermetallic compound containing 20%, having V as an impurity regulated to 80 ppm or less, having a composition composed of the balance Al and inevitable impurities, and having a size (equivalent circle diameter, the same shall apply hereinafter) of 4 mm or more Is formed by hot rolling and cold rolling an aluminum alloy ingot in which an intermetallic compound of 1 piece / m ³ or less and 1 mm or more and less than 4 mm is 10 pieces / m ³ or less. In the following description, alloy components are shown as mass%.

The aluminum alloy sheet for forming according to claim 2 is the aluminum alloy plate according to claim 1, wherein the aluminum alloy ingot further comprises Fe: 0.1 to 0.8%, Cu: 1.2% or less, Mg: 0.4 % Or less, Cr: 0.3% or less, Zn: 0.3% or less, and Zr: 0.3% or less.

The aluminum alloy sheet for forming according to claim 3 is characterized in that, in claim 1 or 2, V as the impurity is regulated to 40 ppm or less.

An aluminum alloy brazing sheet for forming according to claim 4 is obtained by cladding an aluminum alloy brazing material on one side or both sides of an aluminum alloy ingot according to any one of claims 1 to 3, and performing hot rolling and cold It is characterized by being rolled.

According to a fifth aspect of the present invention, there is provided a method for producing an aluminum alloy plate for forming by melting the aluminum alloy according to any one of the first to third aspects and casting at a cooling rate of 0.09 ° C./s to 30 ° C./s. The method includes a step, a step of homogenizing heat treatment of the obtained ingot, a step of hot rolling the ingot subjected to the homogenization heat treatment, and a step of cold rolling the obtained hot rolled plate.

According to the present invention, it is excellent in formability, brazeability and strength after brazing, and particularly an aluminum alloy plate for forming process that is suitably used for heat exchangers such as radiators, car heaters, and car air conditioners, and a manufacturing method thereof, And the aluminum alloy brazing sheet which uses this aluminum alloy plate as a core material is provided.

It is a figure which shows an inverted T-shaped test piece. It is a figure which shows the reverse T-shaped test piece after brazing heating.

The aluminum alloy plate for forming according to the present invention and the aluminum alloy brazing sheet having the aluminum alloy plate as a core material are preferably used as a heat exchanger member. The brazing material of the brazing sheet may be clad on one side or both sides of the core material. The brazing material may be clad on one side and the sacrificial anode material may be clad on the other side.

The part used for the heat exchanger is not particularly limited, but the plate is molded into a circular tube by welding and then deformed into a flat shape, the plate is bent into a flat shape, and the joint is joined during brazing. It is suitable as a member to be used after being molded, such as a tube, a corrugated fin, a plate fin, a header plate, a tank plate, a side plate, and a reinforcing plate.

In order to manufacture a heat exchanger, a plate material and a brazing sheet are a coil cut into a predetermined width or a sheet cut into a predetermined size, and press processing, bending processing, drawing processing, deep drawing processing, cutting processing, etc. To form a predetermined shape.

Hereinafter, the significance and reasons for limitation of the alloy components in the aluminum alloy sheet for forming according to the present invention will be described.
Mn:
Mn is an element that functions to increase strength and improve corrosion resistance, particularly pitting resistance. The preferable content of Mn is in the range of 1.2 to 2.0%. If the content is less than 1.2%, the effect is not sufficient. If the content exceeds 2.0%, a coarse intermetallic compound is formed, and molding Workability is reduced. A more preferable content range of Mn is 1.3% or more and less than 1.8%.

Ti:
Ti is divided into a high-concentration region and a low-concentration region, and these regions are alternately distributed in the thickness direction, and the low-Ti concentration region corrodes preferentially over the high-Ti concentration region. As a result, the corrosion form becomes layered, and as a result, the progress of corrosion in the thickness direction is hindered, and the pitting corrosion resistance, intergranular corrosion resistance and crevice corrosion resistance of the material are improved. The preferable content of Ti is in the range of 0.10 to 0.20%. If it is less than 0.10%, the effect is not sufficient, and if it exceeds 0.20%, a coarse intermetallic compound is produced during casting. As a result, processability deteriorates and a sound material cannot be obtained. A more preferable content range of Ti is 0.11 to 0.18%.

V:
V is an element contained as an impurity in the graphite electrode used when smelting aluminum by the molten salt electrolysis method. Since oxygen of aluminum oxide reacts with carbon of the electrode to form aluminum and carbon dioxide, the graphite electrode made of carbon is gradually consumed, and V is mixed into aluminum as an inevitable impurity.

When Ti is added to an Al—Mn-based aluminum alloy containing a large amount of Mn, Ti becomes a solidified nucleus during casting, and an Al—Mn-based intermetallic compound (Al ₆ Mn or the like) is easily generated. If a large amount of V is contained here, the production temperature of the intermetallic compound becomes high and the intermetallic compound grows greatly, so that a coarse intermetallic compound is produced in the ingot. If the size of the intermetallic compound with a size of 4 mm or more produced at the time of casting is 1 piece / m ³ or less, it is fragmented in the subsequent hot rolling and cold rolling and becomes finer. If it exceeds 1 / m ³ , a coarse intermetallic compound remains even if it is fragmented, so that moldability is lowered. On the other hand, when the size of the intermetallic compound having a size of 1 mm or more and less than 4 mm exceeds 10 / m ³ , the moldability deteriorates. The number of intermetallic compounds having a size of 1 mm or more and less than 4 mm is preferably small. When the V content is reduced, the production temperature of the intermetallic compound is also lowered, so that the growth of the intermetallic compound is suppressed, and as a result, the production of a coarse intermetallic compound can be suppressed. Therefore, it is desirable to regulate V to 80 ppm or less, more preferably 40 ppm or less.

V contains about 100-200 ppm as an inevitable impurity in an aluminum ingot of ordinary purity. Specific methods for reducing the V content include increasing the usage rate of high-purity bullion with a low V content, analyzing the V content contained in the bullion, and only bullion with a low V content. Can be achieved. There is also a method using a coal-based graphite electrode with a low V content instead of using an oil-based graphite electrode with a high V content during aluminum smelting.

Si:
Si forms an Al—Mn—Si based compound or an Al—Mn—Fe—Si based compound and functions to improve the strength. The preferable content of Si is in the range of 0.5 to 1.0%. If the content is less than 0.5%, the effect is small. If the content exceeds 1.0%, a large number of Si compound particles are formed and the corrosion resistance is lowered. To do. A more preferable content range of Si is 0.60 to 0.80%.

Cu:
Cu functions to improve the strength of the alloy. The preferable content is in the range of 1.20% or less, and if it exceeds 1.20%, the corrosion resistance decreases. A more preferable content range of Cu is 0.20 to 1.00%.

Fe:
Fe functions to reduce the crystal grain size of the aluminum alloy material, improve the formability, and prevent the occurrence of rough skin. The preferable content of Fe is in the range of 0.1 to 0.8%. If the content is less than 0.1%, the effect is small. To do. A more preferable content range of Fe is 0.20 to 0.70%.

Mg:
Mg functions to improve the strength of the alloy, but when flux brazing is performed, F contained in the flux reacts with Mg to form a compound, resulting in a decrease in brazing properties. The preferable content of Mg is in the range of 0.4% or less. If it exceeds 0.4%, the brazing property is lowered. A more preferable content range of Mg is 0.20% or less.

Cr and Zr:
Cr and Zr improve the material strength before brazing and after brazing. The preferable contents of Cr and Zr are each 0.3% or less, and if it exceeds 0.3%, a coarse intermetallic compound is produced during casting and the workability is lowered, so that a sound material can be obtained. Disappear.

Zn:
Zn has the effect of lowering the potential of the core material of the plate material or brazing sheet. If it exceeds 0.3%, the self-corrosion resistance is deteriorated.

Size and number of intermetallic compounds in the ingot:
Methods for confirming the intermetallic compounds produced during casting include cutting the ingot to a thickness of about 10 to 30 mm in the length direction, irradiating X-rays and observing the transmitted X-ray image, There is a method of observing the microstructure of a lump. In the method of observing the microstructure, a small intermetallic compound can be confirmed, but since the range that can be confirmed is small, it is not suitable for examining the entire ingot. On the other hand, in the method of observing an X-ray transmission image, coarse intermetallic compounds can be investigated in a wide range of the entire ingot, but it is difficult to confirm intermetallic compounds having a size of less than 1 mm.

Cooling speed during casting:
The cooling rate during casting in DC casting (the cooling rate of the portion excluding the surface layer portion within 20 mm from the ingot surface) is preferably 0.09 ° C./s or more and 30 ° C./s or less. If it is less than 0.09 ° C./s, the production efficiency is lowered, which is not preferable, and the intermetallic compound tends to be large. When the cooling rate is 30 ° C./s or more, the temperature of the molten metal in the mold becomes high, and the molten metal leak is likely to occur.

In the brazing sheet using the forming aluminum alloy plate of the present invention as a core material, an Al—Si alloy containing 6 to 15% of Si is used as the brazing material. For the brazing material, 0.05 to 2% Mg, 0.5 to 10% Zn, 0.05 to 1% Cu, 0.01 to 0.3% Cr, Ti, Bi as required , Sr can also be contained. The brazing material is clad on one side or both sides of the core material as necessary.

In an Al—Si based brazing filler metal, if the Si content is less than 6%, the brazing property is lowered, which is not preferable. If it exceeds 15%, erosion is generated and the tube may be eroded, which is not preferable. . A particularly preferable Si content is 6 to 12.5%. By adding Cu or Mn to the brazing material, the potential of the fillet can be adjusted, and the site where corrosion occurs can be adjusted to a preferred region. Also, in the Al—Si alloy brazing material, Fe can be contained if it is 0.6% or less, and elements such as In, Sn, Ni, Ti, and Cr do not affect the brazing joint property. If necessary, Zn may be contained as long as the thickness of the Zn diffusion layer in the tube is remarkably increased so as not to affect the corrosion resistance.

In the brazing sheet using the aluminum alloy plate for forming according to the present invention as a core material, a brazing sheet in which a brazing material is clad on one side of the core material and a sacrificial anode material is clad on the opposite surface of the brazing material can also be used. For the sacrificial anode material, one or two of 0.5 to 10% Zn, 0 to 2.0% Mn, 0 to 2.0% Si, 0 to 2.0% Fe, as required. More than seeds can be contained.

As a method for producing a brazing sheet, an aluminum alloy ingot having a brazing material component is produced, and a brazing material for brazing material having a predetermined thickness is produced by homogenization treatment and hot rolling. A clad plate is produced by hot clad rolling on one side or both sides of the alloy core material, and is cold rolled to a predetermined thickness. If necessary, intermediate annealing or final annealing may be performed. As the brazing material, a brazing material ingot cut into a predetermined thickness can be used.

In the brazing sheet in which the brazing material is clad on one side of the aluminum alloy core material for forming according to the present invention, the opposite side of the brazing material may be left as the core material, or the opposite surface of the brazing material is used in an environment where the corrosiveness is high. In this case, the sacrificial anode material can be clad to improve penetration resistance.

Hereinafter, examples of the present invention will be described in comparison with comparative examples to demonstrate the effects of the present invention. In addition, these Examples show one embodiment of this invention, and this invention is not limited to these.

Example 1
Aluminum alloys (A to U) having the compositions shown in Table 1 were melted and agglomerated by DC casting. The cooling rate was measured by casting a dummy ingot. In the casting of a dummy ingot, in the molten metal in the mold, at the mold center as viewed from above the mold, the position in the center in the width direction (20 locations from the mold wall in the width direction (two locations), and the thickness in the center. Insert thermocouples into a total of 5 locations (2 locations) 20 mm inside from the mold wall surface in the thickness direction, and fill the melt as it is solidified and measure the cooling rate until the temperature reaches 500 ° C from the start of solidification. The cooling rate of was determined. Check the casting conditions at which the average cooling rate is 0.10 ° C / s or more and 0.20 ° C / s or less, 10 ° C / s or more and 12 ° C / s or less, and 27 ° C / s or more and 29 ° C / s or less, Casting was performed under the same casting conditions as this casting condition, and an ingot having a width of 175 mm, a length of 175 mm, and a thickness of 30 mm was obtained.

The obtained ingot was homogenized at 600 ° C. for 10 hours, and then the rolled surface of the ingot was cut by 2 mm. Then, it heated to the temperature of 500 degreeC, the hot rolling was started, and it hot-rolled to thickness 3mm. The end temperature of hot rolling was 200 ° C. The hot-rolled sheet was cold-rolled to a thickness of 0.4 mm, and subjected to final annealing at 400 ° C. for 3 hours, and the material was classified as O material. The obtained aluminum alloy sheet was used as a test material for the following evaluation, and the size of the intermetallic compound was measured using an ingot. Table 2 shows the evaluation and measurement results.

(Formability)
Formability was evaluated by the elongation of the material. A JIS No. 5 tensile test piece is taken from the test material, a tensile test in accordance with JIS is performed, and the elongation (δ) is measured. When the elongation is 20% or more, excellent (◎), 15% or more and less than 20% Those with good (◯) were all passed, and those with less than 15% were rejected (×).

(Brassability)
As shown in FIG. 1, BAS121P brazing sheet 3 (core material: 3003 alloy, brazing material: 4045 alloy single-sided clad, clad rate: 10 cut into 25 × 50 mm to obtain a vertical plate and cut into 25 × 50 mm. %, Plate thickness: 1.0 mm, tempering: O material), and the brazing material surface of the brazing sheet 3 is in contact with the vertical plate (test material 2) to produce an inverted T-shaped test piece 1 Then, 5 g / m ² of dry paint mixed with a fluoride-based flux and alcohol was applied to the brazing sheet surface of the brazing sheet, and the temperature was raised to 600 ° C. at an average rate of 50 ° C./min in a nitrogen gas atmosphere. Brazing heating was performed to reach the final temperature. The bonded test piece 4 (FIG. 2) was embedded in resin, and the cross-sectional area of the fillet 5 formed on the bonding surface with the vertical plate was measured. After that, the ratio of brazing flow (cross-sectional area of the fillet after brazing / cross-sectional area of the brazing material before brazing) is calculated, and this is used as the flow coefficient by the reverse T-shaped test, and the flow coefficient by the reverse T-shaped test. A value of 0.3 or more was evaluated as pass (◯), and less than 0.3 was evaluated as reject (x).

(Strength characteristics after brazing)
The test material is cut into 50 × 300 mm, and brazing heating is performed in a nitrogen gas atmosphere to a temperature of 600 ° C. (attainment temperature) at an average rate of 50 ° C./min. From the plate after brazing heating, A JIS No. 5 tensile test piece was sampled and subjected to a tensile test based on JIS to measure the tensile strength (σB). Those having a tensile strength of 120 MPa or more were regarded as acceptable (◯), and those having a tensile strength of less than 120 MPa were regarded as unacceptable (x).

(Measurement of intermetallic compound size)
A sample with a thickness of 30 mm is cut and collected from the center of the ingot, and an X-ray transmission device (model number: RAD10FLEX-100GS) manufactured by Rigaku Corporation is used to output a transmission X-ray image at 125 KV and 2 mA. did. A shadow of 1 mm or more in size in the photograph taken was judged as a coarse intermetallic compound, the size and number were measured, and the number per 1 m ³ was converted from the sample size.

As shown in Table 2, all of the test materials 1 to 23 according to the present invention were excellent in moldability and strength after brazing, and had excellent brazing properties.

Comparative Example 1
Aluminum alloys (a to k) having the compositions shown in Table 3 were dissolved, and the cooling rate was 0.10 ° C./s or more and 0.20 ° C./s or less and 0.03 ° C./s by DC casting as in Example 1. The casting was performed at 0.05 ° C./s or less to obtain an ingot having a width of 175 mm × a length of 175 mm × a thickness of 30 mm. In the case of casting at a cooling rate of 35 ° C./s or more and 40 ° C./s or less, since the molten metal leaked from the mold, casting was stopped halfway. In Table 3, those outside the conditions of the present invention are underlined.

The obtained ingot was homogenized, surface-cut, hot-rolled, and cold-rolled under the same conditions as in Example 1 and subjected to final annealing to make an O material. The same evaluation and measurement as in Example 1 were performed using the obtained aluminum alloy plate as a test material. Table 4 shows the evaluation and measurement results.

Since the test materials 24 to 26 had a large amount of V, an intermetallic compound having a size of 4 mm or more was generated during casting, and the elongation rate was low and the moldability was poor. Since the test material 27 had a large amount of Ti, an intermetallic compound having a size of 4 mm or more was generated during casting, and the elongation rate was low and the moldability was poor. Since the test materials 28 and 29 had a small amount of Mn, the strength after brazing was inferior. Since the test material 30 had a large amount of Mg, the brazing property was inferior. Further, each of the test materials 31 to 34 had a high content of Mn, Cr, Zn, and Zr, so that the workability was inferior and a sound plate material could not be produced. Since the test material 35 had a cooling rate that was too slow, an intermetallic compound having a size of 4 mm or more was generated during casting, and the elongation rate was low and the moldability was poor.

Example 2
Using the ingots of alloys D to I cast in Example 1, homogenization treatment and surface cutting were performed in the same manner as in Example 1 to obtain a core material ingot. It is obtained by melting and DC casting a brazing material containing Si: 10%, the balance aluminum and inevitable impurities, and a sacrificial anode material containing Zn: 1%, the balance aluminum and inevitable impurities, in accordance with a conventional method. After the surface of the ingot was cut by 10 mm, it was hot-rolled to a predetermined plate thickness at 500 ° C. to produce a brazing material skin plate and a sacrificial anode material skin plate.

Subsequently, in the combinations shown in Table 5, the brazing material skin or the sacrificial anode material skin material is laminated so as to have a cladding rate of 10% on one or both surfaces of the core material ingot, and heated to 500 ° C. And hot rolled to a thickness of 3 mm. The end temperature of hot rolling was 170 ° C. The hot-rolled sheet is cold-rolled to a thickness of 0.4 mm, subjected to a final annealing at 400 ° C. for 3 hours to make the material O, and the obtained aluminum alloy brazing sheet is used as a test material for the following evaluation. The intermetallic compound size was measured using the core material ingot. Table 5 shows the evaluation and measurement results.

(Formability)
The formability of the brazing sheet was evaluated by the elongation of the material. A JIS No. 5 tensile test piece was collected from the test material, subjected to a tensile test in accordance with JIS, and measured for elongation (δ). Elongation of 20% or more was evaluated as excellent (）), 15% or more and less than 20% was evaluated as good (◯), and any of those with an elongation of less than 15% was rejected (x).

(Strength characteristics after brazing)
The test material was cut to 50 × 300 mm, and a coating material mixed with fluoride-based flux and alcohol was applied to the brazing material surface of the brazing sheet in a dry mass of 5 g / m ² and averaged at 50 ° C./min in a nitrogen gas atmosphere. Brazing heating was performed at a heating rate of 600 ° C. (attainable temperature). A JIS No. 5 tensile test piece is taken from the plate after brazing and heating, and a tensile test according to JIS is performed to measure the tensile strength (σB). If the tensile strength is 120 MPa or more, it passes (○). , Less than 120 MPa was regarded as rejected (x).

(Brassability)
As shown in FIG. 1, the test material 3 cut to 25 × 50 mm was made into a horizontal plate with the brazing material surface facing upward, and a 25 × 50 mm 3003 alloy plate 2 (plate thickness: 1.0 mm, tempered) : O material) was a vertical plate, and the brazing material surface of the test material was brought into contact with the 3003 alloy plate to produce an inverted T-shaped test piece 1. Apply 5 g / m ² of fluoride-based flux and alcohol mixed paint as dry mass on the brazing filler metal surface of the test material, and heat to 600 ° C. (attainment temperature) at an average temperature increase rate of 50 ° C./min in a nitrogen gas atmosphere. Brazing heating was performed. The bonded test piece 4 (FIG. 2) was embedded in resin, and the cross-sectional area of the fillet 5 formed on the bonding surface with the vertical plate was measured. After that, the ratio of brazing flow (cross-sectional area of the fillet after brazing / cross-sectional area of the brazing material before brazing) is calculated, and this is calculated based on the flow coefficient by the reverse T-shaped test and the flow coefficient by the reverse T-shaped test. A value of 0.3 or more was evaluated as pass (◯), and less than 0.3 was evaluated as reject (x).

As shown in Table 5, all of the test materials (aluminum alloy brazing sheets) 36 to 53 obtained according to the present invention were excellent in formability and strength after brazing, and had excellent brazing properties.

DESCRIPTION OF SYMBOLS 1 Inverted T-shaped test piece 2 Example 1 and comparative example 1 are test pieces, Example 2 is 3003 alloy plate 3 Example 2 and comparative example 1 are brazing sheets, Example 2 is test piece 4 Test piece 5 joined Fillet

Claims (5)

1. Mn: 1.2 to 2.0% (mass%, the same applies hereinafter), Si: 0.5 to 1.0%, Ti: 0.10 to 0.20%, and V as an impurity of 80 ppm or less And having a composition composed of the balance Al and inevitable impurities, the generated intermetallic compound having a size (equivalent circle diameter) of 4 mm or more is 1 / m ³ or less, and is between 1 mm or more and less than 4 mm. An aluminum alloy plate for forming, which is obtained by hot-rolling and cold-rolling an aluminum alloy ingot having 10 or less compounds / m ³ .
2. The aluminum alloy ingot further comprises Fe: 0.1 to 0.8%, Cu: 1.2% or less, Mg: 0.4% or less, Cr: 0.3% or less, Zn: 0.3% The aluminum alloy sheet for forming according to claim 1, wherein one or two of Zr: 0.3% or less are contained.
3. The aluminum alloy sheet for forming according to claim 1 or 2, wherein V as the impurity is regulated to 40 ppm or less.
4. An aluminum for forming process, comprising: an aluminum alloy ingot according to any one of claims 1 to 3 clad with an Al-Si alloy brazing material on one side or both sides, and hot rolling and cold rolling. Alloy brazing sheet.
5. A step of melting the aluminum alloy according to any one of claims 1 to 3 and casting at a cooling rate of 0.09 ° C / s to 30 ° C / s, a step of homogenizing heat treatment of the obtained ingot, homogenization A method for producing an aluminum alloy sheet for forming, characterized by comprising a step of hot-rolling the ingot that has been heat-treated and a step of cold-rolling the obtained hot-rolled plate.

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