JPH0557076B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention relates to a welding filler metal used when welding 6000 series aluminum alloy materials together.
In particular, the present invention relates to a welding filler material suitable for welding aluminum materials made of 6000 series aluminum alloy. [Prior Art] When welding aluminum materials made of aluminum or aluminum alloys, a welding wire rod called a filler metal is usually used, but it has good weldability and can achieve high welding strength. In addition, pure aluminum or an aluminum alloy of the same type as the aluminum material to be welded is used as the filler material to prevent problems such as weld cracks. However, if the material to be welded is a 6000 series aluminum alloy material made of a 6000 series aluminum alloy, weld cracking will occur in most cases if a filler metal whose base material is a 6000 series aluminum alloy is used. , the strength of the welded part cannot be achieved (Light Metal Welded Construction Association, "Welding Construction Management of Aluminum Structures", pp. 98-101). Therefore, in order to prevent such weld cracking and lack of strength, conventionally, 4000 series or 5000 series aluminum alloys, such as A4043 or
The base material used is A5356. [Problems to be solved by the invention] However, when a filler metal made of 4000 series or 5000 series aluminum alloy is used when welding an aluminum material made of 6000 series aluminum alloy, the cracking resistance is not improved. Although the problem of weld cracking is eliminated, the color tone between the aluminum material to be welded and the welded part is extremely different, which impairs the beauty of the welded product, and even if there is no problem with the strength of the welded part. If this welded part is exposed to the outside, it will give the viewer a sense of uneasiness regarding the strength.
It is not preferable that there is an extreme difference in color tone between the aluminum material to be welded and the welded part. [Means for Solving the Problems] The present invention was devised in view of this point of view, and provides a new filler metal for welding 6000 series aluminum alloy materials. The present invention provides a filler metal for welding 6000 series aluminum alloys that is used to weld aluminum materials made of alloys, maintains the necessary welding strength, and does not cause weld cracking or color problems. be. That is, the present invention provides a filler for welding a 6000 series aluminum alloy material, which uses a 6000 series aluminum alloy as a base material, and an additive element consisting of titanium and/or zirconium and one or more rare earth elements is added to the base material. It is a material. In the present invention, rare earth elements used as additive elements include lanthanum (La), cerium (Se), praseodymium (Pr), neodymium (Nd),
It is a group of elements belonging to group of the periodic table of elements, such as promethium (Pm) and samarium (Sm), and these can be used alone or in combination of two or more. You may. Regarding this rare earth element, so-called Mitsushi Metal, which is made of a mixture thereof and is commercially available as an ignition alloy, is preferred because it is easily available and inexpensive, and it is economical to use it as it is. This Mitsushi Metal, for example, Se: 45.2% by weight,
La: 30.5% by weight, Nd: 15.3% by weight, Pr: 3.9% by weight, Sm: 1.8% by weight, other rare earth elements: 3.3
It has a composition of % by weight. In addition, in the present invention, the amount of each of the above additive elements is 0.05 to 0.30% by weight for titanium (Ti);
Preferably in the range of 0.05% to 0.25% by weight, for zirconium (Zr) 0.10 to 0.30% by weight, preferably 0.10 to 0.25% by weight, and for rare earth elements 0.01 to 0.50% by weight %, preferably within the range of 0.02 to 0.30% by weight. Furthermore, in the present invention, the titanium and/or
Alternatively, in addition to the additive elements consisting of zirconium and rare earth elements, boron may be added as necessary,
In this case, the amount of boron added is 0.04% by weight or less, preferably within the range of 0.01 to 0.03% by weight. In the present invention, the total amount of added elements is usually
It is in the range of 0.1 to 0.7% by weight, preferably 0.1 to 0.5% by weight. If the amount of additive elements added is less than the above range, the effect of adding these additive elements will not be exhibited, and the susceptibility to weld cracking will increase, creating a risk of weld cracking. If the amount increases, the susceptibility to weld cracking increases, creating a risk of weld cracking, and the stability of the arc during welding is impaired. In addition, regarding the method for manufacturing the filler metal for welding of the present invention, for example,
Al-Ti + Mitsushi Metal alloy, Al-Zr + Mitsushi Metal alloy, Al-Ti-Zr + Mitsushi Metal alloy, Al-Ti + B + Mitsushi Metal alloy, etc. are added as a mother alloy during casting, or as rods with a diameter of about 9 mm during casting. Any suitable method can be adopted. The welding filler metal of the present invention produced in this manner is formed into, for example, a wire rod, a strip material, etc., and used for welding 6000 series aluminum alloy materials in exactly the same manner as conventionally known welding filler metals. can do. [Example] Hereinafter, the welding filler metal of the present invention will be specifically described based on Examples and Comparative Examples. Examples 1 to 16 and Comparative Examples 1 to 2 A. Preparation of filler metal for welding Containing elements other than aluminum shown in Table 1
The base material is 6000 series aluminum alloy, and this base material
Ti, Zr, Ti+B and Mitsushi metal (composition;
Se: 45.2% by weight, La: 30.5% by weight, Nd: 15.3% by weight, Pr: 3.9% by weight, Sm: 1.8% by weight, other rare earth elements: 3.3% by weight) are added as a mother alloy during casting, and billet or Each of the filler metals of Examples 1 to 16 was produced by casting a wire bar, then extruding or rolling it into a wire, and then drawing it into a desired shape. Table 1 shows elements other than aluminum contained in each of the filler metals of Examples 1 to 16 manufactured in this way and their proportions. B Bead-on-plate test 4mm x extruded aluminum alloy A6N01
A test piece with a size of 300 mm x 300 mm was prepared, and the filler metals of Examples 1 to 16 above were used on this test piece, current: 160 to 180 A, voltage: 22 to 24 V, welding speed:
500mm/min., Ar flow rate: 30/min. and heat input:
A bead-on-plate test was conducted using MIG (metal inert gas arc welding) welding under conditions of 3520 to 5180 j/cm. The appearance of the welded part by this bead-on-plate test showed that when the filler metals of Examples 1 to 8 and 13 to 16 were used, there were fewer microcracks and the appearance was good; When filler material was used, microscopic cracks occurred, but the appearance was good. Next, for each of the test pieces welded in this way, the built-up portions at the welded portions were scraped off and flattened, and then the welded portions were subjected to alumite treatment in the following procedure. Degreasing (25% nitric acid, 10 minutes at room temperature) → Washing with water (2 minutes under running water) → Etching (5% caustic soda, 2 minutes at 50°C) → Washing with water (2 minutes under running water)
minutes) → Neutralization (25% nitric acid, 2 minutes at room temperature) → Washing with water (2 minutes under running water) → Alumite (180±5 g/sulfuric acid, constant voltage method, 30 minutes at 16 V) → Washing with water (10 minutes under running water) → Sealing ( (Pure water, boiling for 30 minutes) Before and after this alumite treatment, compare the color of the background of the test piece and the color of the welded part with the naked eye, and determine the degree of color difference: ◎: exactly the same, ○: almost the same,
Evaluation was made on a five-point scale: Δ: Slightly different, ×: Different, and XX: Significantly different. The results are shown in Table 2. In addition, a conventional filler metal made of aluminum alloy A5356 having the following composition for elements other than aluminum was used as Comparative Example 1, and aluminum alloy A4043 having the following composition for elements other than aluminum was used as Comparative Example 2. In each case, a bead-on-plate test was carried out in the same manner as in the above examples, and then an alumite treatment was performed, and the color of the background of the test piece and the color of the welded portion before and after the alumite treatment were compared. The results are shown in Table 2.

[Table] As is clear from the results of evaluation of color difference before and after this alumite treatment, each of Examples 1 to 3,
In the cases of Nos. 5 to 7, 9 to 11, 13, and 14, even if the difference in color is emphasized by the alumite treatment, it is the same as the case before the alumite treatment of each Comparative Example 1 to 2, and the other Examples 4, 8, 12, 15 and 16 of
However, it is slightly inferior to the alumite treatment in Comparative Examples 1 to 2, and the degree of color difference in Examples 1 to 16 is clearly improved compared to Comparative Examples 1 to 2. I understand.

【table】

[Table] C. Fishbone type cracking test Three types of aluminum alloys A5083, A6NO1 and A7NO1 were used to test the thickness 3 as shown in Figure 1.
A crack test piece of mm was prepared, and the filler metal of Examples 1 to 16 above and the filler metal prepared from Al-Mg-based A5356 alloy (Comparative Example 3) were used for the test piece, and the electric current was 95~
115A, welding speed: 165mm/min. and Ar flow rate: 8
A fishbone type cracking test was conducted by performing fully automatic TIG (TIG, tungsten inert gas arc welding) welding in the direction of arrow Y in Figure 1 under conditions of /min. The results of this fishbone type cracking test were obtained by measuring the length of all cracks that occurred in the weld, calculating the ratio of this crack length to the weld length (120 mm),
This value was determined as the cracking rate. The results are shown in Table 3.

【table】

[Table] This fishbone type cracking test is conducted in such a way that cracks are likely to occur, and in fact, it can also be used when A7N01 test pieces are welded using the filler metal of Comparative Example 3. It was found that a cracking rate of up to about 80% is considered to be acceptable as a practical range, and that any of the filler metals of Examples 1 to 16 can be used. In addition, as a result of measuring the strength of the welded part by a normal tensile test, each of Examples 1 to 16 and Comparative Example 3 showed sufficient strength. [Effects of the Invention] The welding filler metal of the present invention is a new filler metal suitable for welding 6000 series aluminum materials, and effectively improves weld cracking and color tint problems that occur during welding. can do.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of a test piece used in a fishbone type cracking test for testing the performance of a welding filler metal according to an embodiment of the present invention.

Claims (1)

[Claims] 1 A filler metal used for welding 6000 series aluminum alloy materials, which uses a 6000 series aluminum alloy as a base material and contains an additive element consisting of titanium and/or zirconium and one or more rare earth elements. , for welding aluminum materials, characterized in that titanium is added in a range of 0.05 to 0.30% by weight, zirconium is added in a range of 0.10 to 0.30% by weight, and rare earth elements are added in a range of 0.01 to 0.50% by weight. Filler metal.