JPH1034380A - Cladding by welding metal and cladding by welding flux cored wire of aluminum or aluminum alloy material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defective welding such as a pit and blowhole or the like, to provide with a high jointing property with an aluminum material and an excellent wear resistance and heat resistance and to stably obtain at a low cost. SOLUTION: A cladding by welding metal 2 is obtained by using a cladding by welding flux cored wire wherein a core material composed of the aluminum or aluminum alloy is filled into a cover composed of a titanium or titanium alloy, and composed of a single structure of only γ phase (TiAl intermetallic compound) or a mixing structure between γ phase and α2 phase (Ti3 Al intermetallic compound). Also, the metal cover of a cladding by welding flux cored wire of the aluminum or aluminum material is composed of the titanium or titanium alloy and the core material of the same is composed of the aluminum or aluminum alloy in the cladding by welding flux cored wire wherein the core material is filled into the metal cover, and the Ti containing quantity to the whole weight of the flux cored wire is specified to be, by wt., 40-90%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a build-up weld metal for imparting wear resistance and heat resistance to aluminum or an aluminum material and a composite wire for build-up weld for obtaining the build-up weld metal. Aluminum or aluminum alloy which can prevent weld defects such as blowholes and blowholes, have high bondability with aluminum materials, and provide a low-cost and stable build-up weld metal with excellent wear resistance and heat resistance The present invention relates to a build-up weld metal for a material and a composite wire for build-up welding.

[0002]

2. Description of the Related Art Aluminum and aluminum alloy materials are used in a wide range of fields such as automobile parts because they are lighter in weight and have better heat conductivity and corrosion resistance than steel materials. Hereinafter, aluminum and aluminum alloy materials are simply referred to as aluminum materials.

[0003] However, aluminum materials are generally inferior in strength, wear resistance and heat resistance as compared with steel materials, and in addition to the improvement of these characteristics, the use environment has recently become severe. Therefore, further improvement in durability of the aluminum material is required. Therefore, attempts have been made to improve durability by forming a coating layer having wear resistance and heat resistance on the surface of an aluminum material. For example, a PVD method or C
There is a method of forming a thin hard coating layer by the VD method, a method of forming a relatively thick hard coating layer by thermal spraying, and the like.

However, when a PVD method or a CVD method is used as a method of forming a film, it is difficult to form a thick film because the film forming speed is low. Further, when a coating is formed by thermal spraying, noise and light rays are generated during the formation, which is a problem in terms of environment. Furthermore, while the coating layers formed by these methods exhibit good hardness, they have poor adhesion to aluminum materials, and the parts or parts where such aluminum materials are used may cause the coating to be damaged during use. There is a risk of peeling or falling off, resulting in reduced reliability.

Therefore, an alloy processing technique using a high energy source such as an electron beam or a laser has been disclosed (JP-A-55-27587). This is to melt the surface of the base material (aluminum material) and the alloying metal to form a hard alloy layer. By using an electron beam, for example, V, Cr, Mn, Fe, Co and Ni And other metal elements (alloying metals) can be alloyed on the substrate surface.

As described above, by using the electron beam of the high-density energy source, the alloying metal having a high melting point can be easily melted and a uniform alloy layer can be obtained. Since the treatment is performed in a vacuum vessel, blowholes and pits are likely to occur due to overheating of the aluminum material, and the productivity is reduced. On the other hand, a laser has a high energy density like an electron beam, but has a low absorptivity to an aluminum material, so that it is difficult to apply the laser. Further, since the electron beam and laser generators are expensive, the use of them increases the manufacturing cost of parts.

On the other hand, the durability of the aluminum material can be improved by hardening the surface of the aluminum material with a TIG arc or a MIG arc. For example, aluminum or aluminum alloy powder and Nb
A method of using a powder mixed with C powder, TiC powder or VC powder as a filler material (Japanese Patent Application Laid-Open No. 58-179569), a composite solution in which a metal wire other than aluminum or a ceramic wire is housed in an aluminum sheath. There is a method using an additive (JP-A-3-169495, JP-A-3-169496).

[0008] However, when a mixed powder of a ceramic powder such as NbC powder or TiC powder and an aluminum alloy powder is used, the ceramic powder such as carbide is generally crushed powder, so it is a deformed powder, and stable feeding is possible. It is difficult, and in the case of a powder mixture of powders having different specific gravities, the composition becomes non-uniform. Therefore, since the amount of dilution of the added metal varies, the composition of the obtained alloy layer becomes non-uniform, which causes variations in properties such as wear resistance and heat resistance.

[0009] Metal powder such as aluminum alloy powder is generally produced by a gas atomization method or a water atomization method, and contains a large amount of gas. When an aluminum material is welded using such a metal powder, H ₂ , N _2, O _{2, and the} like are easily absorbed from a filler material containing a gas in a molten state, and these gases are pits and blow holes. Etc., which may cause welding defects.

[0010] Further, as a welding wire, a composite wire in which a core wire made of an Al-based material is filled in an outer skin made of a Cu-based material is used, and the surface of the aluminum material is welded to the surface of the aluminum material by gas shielded arc or plasma arc overlay welding. A technique for forming an alloyed layer has been disclosed (JP-A-5-2388).
No. 5 publication). Thereby, an alloyed layer composed of the θ phase is formed on the surface of the aluminum material, and the wear resistance and heat resistance of the aluminum material can be improved.

Further, there is disclosed a welding wire for overlay welding in which the melting point of the core metal is lower than the melting point of the shell metal, and the Al content is 15% by weight based on the total weight of the composite wire. (JP-A-5-57480). Thus, if the melting point of the core metal is lower than the melting point of the shell metal, the shell metal does not melt first, and the core material and the shell are alloyed by arc heat and Joule heat,
Since the droplet moves to the aluminum material side, a good build-up metal can be obtained.

[0012]

However, when a welding wire disclosed in Japanese Patent Application Laid-Open No. Hei 5-23885 is used,
As a skin metal, C, which has a much higher specific gravity than Al
Since u is used, the weight of the built-up portion becomes extremely large. There is also a problem that heat resistance is low and hardness at high temperatures is extremely low.

Further, in the welding wire disclosed in Japanese Patent Application Laid-Open No. 5-57480, the amount of oxygen and the like in the composite wire is not specified simply by using a core material having a lower melting point than the outer metal. When such a composite wire is manufactured, an oxide film or the like is likely to remain at the interface between the coating material and the core material, which has a problem that it has a bad influence on a blow hole at the time of welding, a structure of a weld metal, and the like. In particular, in the case of a build-up weld metal using a welding wire using titanium as a skin and aluminum as a core material, if the amount of oxygen in the wire increases, it is likely to become Al ₂ O ₃ during welding,
This causes unevenness of the structure, blow holes and weld cracks.

The present invention has been made in view of such problems, and can prevent welding defects such as pits and blowholes, and has a high bondability with aluminum materials, and has abrasion resistance and heat resistance. It is an object of the present invention to provide a build-up weld metal of aluminum or an aluminum alloy material and a composite wire for build-up welding, which are excellent in quality and can be obtained stably at low cost.

[0015]

An aluminum or aluminum overlay welding metal according to the present invention is a composite wire for overlay welding in which a shell made of titanium or a titanium alloy is filled with a core material made of aluminum or an aluminum alloy. And is characterized by being composed of a single-phase structure having only a γ-phase.

[0016] Another overlay welding metal of aluminum or aluminum according to the present invention uses a composite wire for overlay welding in which a core made of aluminum or aluminum alloy is filled in a skin made of titanium or titanium alloy. And a mixed structure of a γ phase and an α ₂ phase. The γ phase is a TiAl intermetallic compound, and the α ₂ phase is a Ti ₃ Al intermetallic compound.

The composite wire for overlay welding of an aluminum or aluminum alloy material according to the present invention is a composite wire for overlay welding in which a core is filled in a metal sheath, wherein the metal sheath is made of titanium or a titanium alloy; The core material is made of aluminum or an aluminum alloy,
The Ti content is 40 to 90% by weight based on the total weight of the welding wire, and the oxygen content is 0.2% or less based on the total weight of the welding wire.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive experiments and research conducted by the present inventors to solve the above-mentioned problems, a composite wire (Ti) in which an outer shell made of titanium or a titanium alloy is filled with a core material made of aluminum or an aluminum alloy. -Al composite wire) is used as a build-up welding wire, and by adjusting the Ti content and the oxygen content to appropriate amounts, it is possible to obtain a build-up weld metal having excellent wear resistance and heat resistance. Was. Specifically, Ti is contained on the surface of the aluminum material by feeding a Ti-Al composite wire into an arc generated between the aluminum material shielded by the inert gas and the non-consumable electrode. Weld metal can be formed.

Hereinafter, the structure of the build-up weld metal according to the present invention and T used as an outer shell component of the composite wire for build-up welding are described.
The reason for limiting the content of i and the amount of oxygen in the composite wire will be described.

Structure of overlay weld metal: single phase structure of only γ phase
Or, in a build-up weld metal formed using a mixed structure Ti-Al composite wire of a γ phase and an α ₂ phase , if a γ phase structure is present, wear resistance at high temperatures, high temperature hardness and heat resistance are reduced. It will be excellent. Therefore, the structure of the build-up weld metal is a single phase of γ phase only or γ phase and α
_It shall consist of a two-phase mixed structure with two phases.

Ti: 40 to 90% by weight As described above, in order to make the γ-phase structure exist in the overlay welding metal, it is necessary to regulate the Ti content to an appropriate amount with respect to the total weight of the welding wire. There is. That is, if the Ti content relative to the total weight of the welding wire is less than 40% by weight, the Ti content of the weld metal obtained by welding becomes insufficient, so that a γ phase is not formed and Al ₃ which has a brittle property at room temperature. Ti is formed. Accordingly, cracks are easily generated, and a weld metal having excellent wear resistance and heat resistance cannot be obtained. On the other hand, when the Ti content is 9
When more than 0 wt%, mixed structure of single-phase or alpha ₂ phase and αTi phase of alpha ₂ phase by a lack of the Al content is formed,
The high-temperature hardness is extremely low, and the wear resistance is low. Therefore, the Ti content relative to the total weight of the welding wire is 4
0 to 90% by weight.

When the Ti content is within the range of the present invention, as the Ti content increases, the structure of the weld metal becomes α ₂ phase (Ti ₃ Al intermetallic compound) and γ phase (TiAl intermetallic compound). And the two kinds of intermetallic compounds form a lamellar structure. As the Ti content decreases, a single phase structure of the γ phase is formed. Accordingly, any of the weld metals having these structures has excellent wear resistance at high temperatures, high-temperature hardness, and heat resistance.

Oxygen content in the composite wire: 0.2% by weight or less Oxygen mainly remains in the form of Al ₂ O ₃ and TiO ₂ at the interface between Al and Ti which is the core material during the production of the composite wire. If the combined oxygen amount exceeds 0.2% by weight based on the total weight of the composite wire, blow holes and pits are formed during welding, and Al ₂ O ₃ is preferentially generated, and uniform γ is generated.
Phase and the formation of the α ₂ phase, resulting in a decrease in hardness. Therefore, the oxygen content is 0.2% by weight based on the total weight of the composite wire.
The following is assumed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the overlay welding metal and overlay welding composite wire of aluminum or aluminum alloy material according to the present invention will be specifically described below in comparison with comparative examples.

First, composite wires having various Ti / Al ratios are manufactured by using a skin made of titanium and a core material made of aluminum, and using these composite wires, a bead-on-plate method (single-layer embossing) is performed. Overlay welding was performed on the aluminum plate. As a manufacturing method, for example, a method of inserting a core material made of aluminum into a skin pipe made of titanium by a vibration method and drawing a wire, or a method of forming a hoop made of titanium into a curve and wrapping a core material made of Al to draw a wire. And the like.

In this embodiment, a pure titanium tape of JIS H 4600 TR270C is used as the outer skin of the composite wire, and JIS H 4040 A is used as the core material.
Using a 1050 W pure aluminum rod, the diameter is 2.
A composite wire measuring 0 mm was produced. Also, as an aluminum plate serving as a base material, 50 mm × 100 mm × 10 m
JIS A 1050P aluminum plate using a gas shielded arc (TIG
Welding, MIG welding) or plasma arc welding. Table 1 below shows these welding conditions.

[0027]

[Table 1]

Next, the weld overlay formed by this welding was evaluated for welding defects, bead appearance, hardness and structure of the weld metal. However, the detection and evaluation of welding defects such as blow holes are performed according to JIS Z 3105.
The test was conducted in accordance with the radiation transmission test and the classification method of the transmission photograph of the aluminum welded part. The hardness, the structure, and the like of the build-up weld metal were evaluated by preparing a cross-sectional test piece of the welded portion.

FIG. 1 is a schematic sectional view showing a sampling position of a test piece for measuring the hardness of the overlay metal. The build-up weld metal 2 is formed so as to extend in a direction parallel to the longitudinal direction of the aluminum plate 1, and FIG. 1 shows a cross section taken along a plane perpendicular to the longitudinal direction of the aluminum plate 1. As shown in FIG. 1, a weld metal 2 is formed on the surface of an aluminum plate 1, and the surface of the aluminum plate 1, which is a base material, is welded while the surface of the aluminum plate 1 is melted. It is formed in a shape that swells up and down from the surface.

A test piece for hardness measurement is taken from a position A of 1 mm from the upper surface of the weld metal 2 toward the inside, and a load is applied in a direction parallel to the upper surface of the aluminum plate 1 and perpendicular to its longitudinal direction. The hardness was measured as described above. The hardness was measured using a Vickers hardness tester and the load was 30
0 g.

The hardness at high temperature was measured in the atmosphere while keeping the test piece for hardness measurement at a temperature of 300 ° C. Tables 2 to 5 below show the conditions and evaluation results of these welding wires. Table 2 is an example using MIG welding, Tables 3 and 4 are examples using TIG welding, and Table 5 is an example using plasma welding.

From the viewpoint of wear resistance, the hardness of the weld metal is not less than HV 200 at room temperature in the Vickers hardness test.
It is necessary to be above. In the columns of peeling, cracking, and bead shape in Tables 2 to 5, ○ indicates good and x indicates bad.

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

As shown in Tables 2 to 5 above, Example N
o. 1-6, 21-26 and 41-46, since the content of Ti with respect to the total weight of the welding wire is within the range of the present invention, the structure of the build-up weld metal formed on the surface of the aluminum plate has a single gamma phase. A phase structure or a lamellar structure in which the α ₂ phase and the γ phase were mixed was obtained. Therefore, it shows excellent values in both hardness at normal temperature and 300 ° C., and has good heat resistance, and does not generate welding defects such as poor fusion and cracks and blowholes and pits. Was excellent.

On the other hand, in Comparative Example No. 7-9, 27-29 and 47-49, the Ti content is less than the lower limit of the range of the present invention, so that the structure of the build-up weld metal is hard and brittle Al ₃ T
The i-phase was formed unevenly. Therefore, cracks occurred on the surface of the bead during cooling or due to a small impact, and the shape of the bead deteriorated due to the occurrence of pits and blowholes.

Further, in Comparative Example No. 10, 11, 30, 3,
In Nos. 1, 50 and 51, since the Ti content exceeded the upper limit of the range of the present invention, no γ phase was formed in the structure of the overlay weld metal, and only the α ₂ phase or the α phase was formed. Therefore, a low value was shown in the hardness test at room temperature, and the heat resistance was also lowered. Further, in Comparative Example No. In the case of Nos. 32 to 37, the Ti content is within the range of the present invention, but since the oxygen content with respect to the total weight of the welding wire exceeds the upper limit of the range of the present invention, Al ₂ O ₃ is formed in the structure in the overlay metal. In some cases, peeling cracks were generated, and bead shapes were deteriorated due to generation of pits and blow holes.

In the present invention, pure titanium is used as the material of the outer skin constituting the welding wire, and pure aluminum is used as the material of the core material. However, a titanium alloy is used as the material of the outer skin, and an aluminum alloy is used as the material of the core material. Can also. That is, in the case of a titanium alloy, for example, Si, Ni,
Zr, Cr, Co, V, Nb, Mo, Ta, Sn, Fe
And Al or the like, and in the case of an aluminum alloy, for example, Si, Cu, Mg, Ni, Mn, Ti,
It may contain Cr and Fe.

The cross-sectional shape of the surface of the core material perpendicular to the longitudinal direction can be, for example, a circle, an ellipse, or a rectangle.

[0042]

As described in detail above, according to the present invention,
Ti or Ti alloy is used for the outer skin of the welding wire, and Al or Al alloy is used for the core material.
Since the i content and the oxygen content are regulated to appropriate amounts, a γ phase is formed in the structure of the weld metal, which can prevent welding defects such as pits and blowholes, and also have a good bondability with aluminum materials. In addition, a build-up weld metal having high wear resistance and excellent heat resistance can be stably obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a sampling position of a test piece for measuring the hardness of an overlay metal.

[Explanation of symbols]

 1; aluminum plate 2; weld metal

Claims (3)

[Claims] 1. A composite wire for overlay welding in which a skin made of titanium or a titanium alloy is filled with a core material made of aluminum or an aluminum alloy, and has a single-phase structure of only a γ phase. Overlay weld metal of aluminum or aluminum alloy material. 2. A composite welding wire obtained by using a cladding welding wire in which a core made of aluminum or an aluminum alloy is filled in a skin made of titanium or a titanium alloy, and a mixed structure of a γ phase and an α ₂ phase is obtained. A build-up weld metal of aluminum or an aluminum alloy material, characterized in that: 3. A composite wire for overlay welding in which a metal sheath is filled with a core material, wherein the metal sheath is made of titanium or a titanium alloy, and the core material is made of aluminum or an aluminum alloy. A composite wire for overlay welding of an aluminum or aluminum alloy material, wherein the content of Ti is 40 to 90% by weight based on the total weight and the amount of oxygen is 0.2% by weight or less based on the total weight of the welding wire.