JPH06142978A - Al-cu composite wire for multilayered build-up welding to al base material surface - Google Patents

Abstract

PURPOSE:To provide the wire with which weld defects, such as pits and blowholes, in the surface of the base material are not generated and a wear- resistant and hear-resistant multilayerd build-up layer having high joinability to an Al base material is inexpensively obtd. CONSTITUTION:This Al-Cu composite wire for build-up welding to the surface of the Al base material is constituted by filling a core material wire consisting of the Al base material into an outer skin consisting of a Cu base material. The content of the Cu is 20 to 50% of the total weight of the composite wire. When the hydrogen quantity of the Cu base material of the outer skin material is designated as H1, the hydrogen quantity existing in the core material wire and at the boundary between the outer skin material and the core material wire, as H2, the oxygen quantity of the Al base material of the core material wire, as O1, the oxygen quantity existing in the outer skin material and at the boundary between the outer skin material and the outer skin material, as O2, H1+H2:<30ppm and O2+O2:<500ppm are attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a gas shielded arc multi-layered meat in which a wear-resistant and heat-resistant layer is stably and economically obtained on the surface of an Al-based material, and further, welding defects such as pits and blow holes are less likely to occur. The present invention relates to a welded Al-Cu composite wire (hereinafter referred to as a wire).

[0002]

2. Description of the Related Art Al or Al alloys are used in a wide range of fields including automobile parts because they are lighter in weight and excellent in heat conductivity and corrosion resistance as compared with steel materials.
However, Al alloys are generally inferior in strength, wear resistance, and heat resistance to steel materials, and the Al alloy materials as they are cannot be applied to alternative parts of steel materials. Further, even when Al or Al alloy is already used, in recent years, further improvement in durability is required as the use environment becomes severe.

As a countermeasure, in addition to the improvement of the Al alloy itself, a method of forming a wear resistant and heat resistant layer on the surface as described below is performed. (1) There are a method of forming a thin hard coating layer on the surface of an Al-based material by PVD, CVD, and a method of forming a relatively thick hard coating layer by thermal spraying. However, the film formed by these methods is very hard, but the adhesion to the base material is weak, and there is a risk of peeling or falling off during use, resulting in poor reliability. Furthermore,
PVD and CVD have a slow film formation rate, and it is difficult to form a thick film. In the case of thermal spraying, there are problems in terms of environment such as generation of noise and light rays, and there is a problem that the adhesion to the substrate is low and peeling occurs during use.

(2) A method of forming a hard alloy layer by melting an alloying metal together with the surface of an Al base material using a high-density energy source such as an electron beam or a laser is disclosed.
For example, JP-A-55-27587 discloses that V, Cr, Mn, Fe and C applied to an Al alloy piston by an electron beam.
An alloying treatment technique for o and Ni is disclosed. Actual Kaisho 6
2-72456, Japanese Utility Model Laid-Open No. 62-72458 also discloses a Cu alloying technique using an electron beam. However, if an electron beam of a density energy source is used, an alloying metal having a high melting point can be easily melted and a uniform alloy layer can be obtained. However, since the alloying treatment by the electron beam is performed in a vacuum container, When the Al alloy is overheated, blowholes and pits are easily generated and the productivity is low.
A laser has a high energy density like an electron beam, but is not suitable for Al and Al alloys because of its low absorptance. Further, since the electron beam and laser devices are both expensive, the cost of the applicable parts is high.

(3) As a method of using MIG arc, TIG arc, and plasma arc for hardening the surface of an Al-based material, Japanese Patent Laid-Open No. 179569/1983 discloses that Al is used as a filler material.
Alternatively, there is disclosed a method of surface hardening an Al-based material by plasma arc using a mixed powder of Al alloy powder and NbC powder, TiC powder, and VC powder. In addition, JP-A-2
No. 2,906,942 and Japanese Patent Application Laid-Open No. 2-290695, there is disclosed a method for modifying the surface of Al using a composite filler material in which powders of B, Si, Ge, boride, silicate, etc. are contained in an Al shell. It is disclosed.

However, when powder is used as the filler material, there are problems such as stable feeding of the filler material and segregation of the composition, and it is difficult to obtain an alloy layer having a uniform composition. For example, in a mixed powder of ceramics such as NbC and TiC powders and Al alloy powder, ceramics such as carbides are generally crushed powders and thus are irregular shaped powders, stable feeding is difficult, and mixed powders having different specific gravities are A compositionally uniform feed is difficult. Therefore, the amount of dilution of the added metal varies, and the composition of the obtained alloy layer becomes non-uniform, which causes variations in characteristics such as wear resistance and heat resistance.

In the case of using the composite wire containing the powder in the Al sheath, if the melting point of the powder encapsulated inside the Al sheath is higher than that of the Al sheath metal, the Al sheath metal is melted first, and then the encapsulated powder. Will be melted. When such a phenomenon occurs, segregation of the components is likely to occur in the alloy layer, such as a portion having a large amount of outer metal component and a portion having a large amount of powder component in the alloy layer, and it is difficult to obtain an alloy layer having a uniform composition. Also, A
In the welding of Al alloy, H ₂ in the molten state,
Since it is easy to absorb N ₂ , O _2, etc., it is easy to generate welding defects such as blow holes and pits. Especially the skin composition of the filler metal,
Alternatively, there is a problem in that welding defects such as blowholes and pits are likely to occur when a large amount of gas component is brought from the powder contained in the outer skin.

[0008]

The present invention has been made to solve the problems of the alloying treatment as described above, and its purpose is to provide pits, blowholes, etc. on the surface of an Al-based material. The object of the present invention is to provide a wire which does not cause welding defects and which has a high bondability with a base material, is stable in wear resistance and heat resistant multilayer build-up layer, and can be obtained at low cost.

[0009]

In order to achieve the above object, a structure as a multilayer build-up material on the surface of an Al-based material according to the present invention is as follows: a core made of an Al-based material in an outer shell made of a Cu-based material. It is a wire filled with wire, and further
The amount of Cu is 20 to 50% (hereinafter abbreviated as%) with respect to the total weight of the composite wire, and the amount of hydrogen of the Cu-based material of the outer covering material is H ₁ , the core wire and the outer covering material and the core material wire. The amount of hydrogen existing at the interface is H ₂ , the amount of oxygen of the Al-based material of the core wire is O ₁ , and the amount of oxygen existing at the outer skin material and the interface between the outer skin material and the core wire is O 2.
_{When set to 2} , H ₁ + H ₂ : less than 30 ppm, O ₁ + O
₂ : The point is that it is less than 500 ppm.

[0010]

According to the present invention, the wire is fed or the Al-Cu composite wire is fed into the arc generated between the non-consumable electrode and the Al base material base material shielded by the inert gas. By feeding as a consumable electrode, a buildup layer containing Cu can be formed on the surface of the Al-based material. Specifically, A
An overlay material for forming a wear-resistant and heat-resistant multilayer overlay layer on the surface of the l-base material was examined. As a result, the desired wear resistance,
It is desirable that heat resistance be stably obtained, and that a core material wire made of Al or an Al alloy is filled in a pipe or hoop of Cu or a Cu alloy in terms of economical efficiency, manufacturability (drawability) and the like. I found it.

Further, the hardness of the build-up layer obtained in this case is required to have Vickers hardness of Hv150 or more from the viewpoint of wear resistance, and if it is less than Hv150, improvement of wear resistance is not expected. The structure of the overlay layer formed by the wire is composed of a mixed structure of the eutectic structure of the α phase (Al) and the θ phase (CuAl ₂ ) and the θ phase in the Al-Cu alloy phase diagram, and the amount of Cu in the overlay metal is When the amount increases, the precipitation amount of the θ phase increases, so that the hardness increases and the wear resistance and heat resistance can be improved. That is, Cu in the overlay metal
Vickers hardness H by adjusting the amount to about 15-55%
It can be set to v150 to 350, and wear resistance and heat resistance can be secured.

That is, the present inventors have found that the amount of Cu in the wire is 1
0%, 20%, 30%, 40%, 50%, 60%, 70
%, 80% wire (1.2 mmφ) was manufactured as a prototype, and laminated welding was performed by the MIG welding method under the laminating procedure shown in FIG. 1 (4 layers stacked) and the welding conditions shown below. amount,
The hardness, the presence or absence of cracks, and the structure were investigated. The dilution ratio of each layer was determined by the total dilution area (D) × 100 / total weld metal area (C) as shown in FIGS. 2 (a) and 2 (b).
It was 30-40%.

Welding conditions Polarity: DCEP Current: 140A Arc voltage: 21V Welding speed: 40 cm / min Oscillation: Width; 3 mm Number of times: 100 times / min Shield gas: Ar; 251 / min

The survey results are shown in FIGS. 2 (a) and 2 (b). In FIGS. 2 (a) and 2 (b), C in the wire in single layer welding
When the amount of u is 30 to 80%, the hardfacing metal exhibits a mixed structure of eutectic and theta phase, the hardness is Hv 150 to 350, and there is no crack generation, but in the case of two-layer welding, the range is 20 to 60%, Three
It was found that in the 1-layer and 4-layer welding, a built-up metal having good wear resistance can be obtained when the amount of Cu in the wire is 20 to 50%.

However, when the amount of Cu in the wire exceeds 60%, Cu in the overlay metal is used in multilayer overlay welding (two or more layers).
As the amount of Cu increases and the amount of Cu in the overlay metal exceeds about 55% and a brittle η ₂ phase appears, the hardness exceeds Hv350 and cracks occur in the overlay metal. Also, the amount of Cu is 20%
When the amount is less than the above, the amount of Cu in the overlay metal obtained by the multilayer overlay welding is insufficient and almost only the α phase is obtained, and the hardness thereof does not reach Hv150 and is not suitable as a wear resistant material. Therefore, the Cu content of the Al-Cu composite wire in which the core wire made of the Al base material is filled in the outer skin made of the Cu base material needs to be in the range of 20 to 50%.

In overlay welding on the surface of Al-based material,
-The major cause of the occurrence of holes and pits is in the filler metal
Gases such as hydrogen, oxygen, nitrogen, etc. contained, or water, etc.
To be In particular, the hydrogen content H of the Cu-based material of the skin material₁And core material
Amount H of hydrogen existing at the interface between the core wire and the core wire₂When
When the total amount of Al exceeds 30ppm, hydrogen is generated in the overlay metal.
The resulting blowholes and pits suddenly occur. Therefore
H₁+ H₂Is limited to less than 30 ppm. In addition, the outer skin material
Amount of hydrogen H₁Is present in the skin and the surface of the skin
Includes hydrogen adhering to the surface. In addition, the method of measuring the amount of hydrogen
Then, it measures by the vacuum heating extraction method. Also, Cu-based material
Oxygen is Cu₂O + H₂= 2Cu + H ₂As shown by O
And reacts with hydrogen in the atmosphere to generate water vapor and blow blow
Forming pits.

That is, the oxygen content O ₁ of the Al-based material of the core wire,
Oxygen content O present at the skin material and at the interface between the skin material and the core wire
_When the total amount of ₂ and 500 is 500 ppm or more, the above reaction becomes active and blowholes and pits are generated. Therefore, O ₁ +
O ₂ is limited to less than 500 ppm. After measuring the amount of hydrogen and oxygen present at the interface between the skin and the core wire after measuring the surface of the skin, the amount of hydrogen present in the skin, the amount of oxygen and the amount of hydrogen present in the core, and the amount of oxygen , The amount of hydrogen and the amount of oxygen of the entire composite wire are measured, and the difference is calculated.

As a method for producing a wire in which a core material wire made of an Al base material is filled in an outer skin material made of a Cu base material according to the present invention, a metal pipe is proposed as disclosed in JP-A-62-2444519. A method in which a core metal wire is inserted into the inside by a vibration method and drawn, or a method in which a Cu-based hoop is curvedly formed into a tubular shape and a core material made of an Al-based material is wrapped and then wire-drawn is used. . The core material made of an Al-based material may be a wire rod or pipe having a circular, elliptical, or rectangular cross-section, and the core material may be an alloy element of a normal Al alloy, for example, Si, Fe, Cu, Mn. , Mg, C
r, Zn, Zr, Ti, etc. may be contained within a range that does not affect toughness and wire drawability.

[0019]

EXAMPLES In order to confirm the effect of the present invention, Al alloy material A
Using the wire shown in Table 1 on the surface of 5083P, a four-layer overlay welding test was performed by MIG welding of a consumable electrode type gas shielded arc welding method and TIG welding of a non-consumable gas shielded arc welding method. Table 2 shows the welding conditions according to each welding method. The laminating method of the four-layer overlay welding is shown in FIG. Incidentally, MIG
Dilution rate of each layer in welding and TIG welding is 30-40%
Met. With respect to the overlay metal obtained by the above-mentioned multilayer overlay welding test, the hardness of the final layer of the overlay metal, the structure, cracks of the overlay metal, blow holes, pits, bead appearance, etc. were investigated. The hardness, structure, cracks, etc. of the overlay of the final layer were investigated using welded section test pieces. The hardness of the overlay metal of the final layer is the average value of the results measured at a pitch of 0.5 mm between AB at a position 1 mm below the bead surface as shown in FIG. The test method and the evaluation method of the blow hole were performed according to the radiation transmission test method of the aluminum weld and the classification method of the transmission photograph (JIS Z 3105), and the pits were evaluated by visual appearance inspection.
Table 3 shows the results of each survey.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

No. 1 in Table 3 1 to 10 are examples of the present invention satisfying all the requirements of the present invention. The structure of the overlaying metal layer on the surface of the Al base material is a mixed structure of θ + eutectic and has a predetermined hardness and the occurrence of cracks. In addition, no blowholes were observed in the results of the radiation transmission test, and all were of the first grade, and there was no pit and a good bead shape was obtained. On the other hand, N
o. No. 11 is overlay welding by MIG welding method.
The structure of the overlay metal layer is a mixed structure of θ + eutectic and has a predetermined hardness, but O ₁ + O ₂ is high and blowholes and pits frequently occur in the overlay metal, and the bead shape is also poor. there were. No. Reference numeral 12 is a weld overlay welded by the MIG welding method. The overlay metal layer structure is a mixed structure of θ + eutectic and has a predetermined hardness, but H ₁ + H ₂ is a comparative example. Blow holes and pits were generated in the overlay metal, and the bead shape was also poor.

No. No. 13 was a weld overlay welded by the MIG welding method. Since the amount of Cu was high relative to the total weight of the wire, the structure of the overlay metal layer was θ and hard and brittle η ₂ , and the hardness of the overlay metal was high. A crack occurred. Blow holes were not recognized in the results of the radiation transmission test, and all were of the first grade, and a good bead shape without pits was obtained. No. No. 14 is the weld overlay welded by the TIG welding method. Since the amount of Cu with respect to the total weight of the wire is low, the structure of the overlay metal layer is a eutectic structure, and the area ratio of α phase is high. And low in abrasion resistance. Blow holes were not recognized in the results of the radiation transmission test, and all were of the first grade, and a good bead shape without pits was obtained.

No. No. 15 is a comparative example in which the overlay welding was performed by the TIG welding method, and the overlay metal layer structure was a mixed structure of θ + eutectic and had a predetermined hardness, but H ₁ + H ₂ was high. Blow holes and pits were generated in the overlay metal, and the bead shape was also poor. No. No. 16 is the weld overlay welded by the TIG welding method. Since the amount of Cu with respect to the total weight of the wire is high, the structure of the overlay metal layer is θ and hard and brittle η ₂ , and the hardness of the overlay metal is high. A crack occurred. Blow holes were not observed in the results of the radiation transmission test, and all were 1
It had a good bead shape with no pits.

[0026]

As described above, when the wire of the present invention is used, welding defects such as pits and blowholes do not occur, and a highly wear-resistant and heat-resistant alloyed layer having high bondability with a base material is stabilized. Then, it can be formed at low cost.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a laminating method and a hardness measurement position of an overlay metal of the present invention or a comparative example,

FIG. 2 is a diagram illustrating a dilution rate,

FIG. 3 shows the amount of Cu, hardness, and cracks in each overlay and overlay metal,
It is a figure which shows an organization.

[Explanation of symbols]

 1 Al plate 2 Overlay metal 1st layer 3 Overlay metal 2nd layer 4 Overlay metal 3rd layer 5 Overlay metal 4th layer A, B Hardness measurement position C Total weld metal area D Total dilution area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Kobe 3-5-4 Tsukiji, Chuo-ku, Tokyo Nittetsu Welding Industry Co., Ltd.

Claims (2)

[Claims] 1. An Al-Cu composite wire for overlay welding on the surface of an Al-based material in which a core wire made of an Al-based material is filled in an outer shell made of a Cu-based material, wherein the amount of Cu is the total weight of the composite wire. On the other hand, 20 to 50% by weight is an Al-Cu composite wire for multilayer build-up welding on the surface of an Al-based material. 2. The amount of hydrogen in the Cu-based material of the outer cover material is H ₁ , and the amount of hydrogen existing in the core wire and at the interface between the outer cover material and the core wire is H.
₂ , where O _{1 is} the oxygen content of the Al-based material of the core wire and O ₂ is the oxygen content present at the outer skin material and at the interface between the outer skin material and the core wire, the following equations (1) and (2) are obtained: A for multilayer build-up welding on the surface of an Al-based material according to claim 1, which is satisfied.
1-Cu composite wire. H ₁ + H _2: 30 ppm less than ........ (1) O ₁ + O _2: 500 ppm less than ......... (2)