JP2703713B2 - Composite powder materials for powder plasma welding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbide composite powder material for powder plasma welding for obtaining a cladding layer having uniform and excellent wear resistance.

[0002]

2. Description of the Related Art Conventionally, means for imparting wear resistance to the surface of iron-based materials include:
When the Fe-Cr-based material is overlaid by arc welding, or when corrosion resistance is required, the so-called stellite alloy of Co-Cr-W is overlaid by gas welding or TIG arc welding. Various measures are taken in consideration of quality and economy.

Among them, powder plasma welding has recently been developed and put to practical use, and has a very wide range of applications as a welding material. The welding material is powder, which is easy to automate and precise. Since it is possible to build up and has a wide range of applications as welded materials from small parts to large parts, it is a welding method suitable for overlay welding, so its application is expanding.

[0004] In particular, since powder materials are used, ceramic materials that could not be considered in conventional overlay welding can be used as welding materials, so that application is expected to be expanded to fields that have not been studied before. By the way.

However, at present, carbide-alloy mixed powder materials obtained by mixing W carbide, Cr carbide, and Nb carbide powders and Ni, Co, and Fe-based atomized alloy powders are used only in a small part. It's just

[0006] This is because the carbide material is a deformed powder having a square shape by pulverized powder, so that stress concentration inside the overlay metal is large and there is a problem in crack resistance. There is a large difference in the mixing ratio at the time of welding, and there is a problem in the uniform dispersion in the welding direction.In addition, the difference in specific gravity between the carbide material and the molten metal, the wettability, etc. This is largely due to the problem that the particles are not uniformly dispersed in the directions.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a carbide composite powder material for powder plasma welding for solving the above-mentioned problems of the prior art and obtaining a cladding layer having uniform and excellent wear resistance. Is what you do.

[0008]

The present inventors have attempted to solve the above problems by developing a carbide composite powder material suitable for powder plasma overlay welding. As a result, we focus on solid solution carbides of W and Ti, which are excellent in weldability and uniform dispersibility as a carbide material, are high in hardness, and are relatively stable even at high temperatures, and add an appropriate amount of Ni or Co to this, and granulate and sinter. As a result, the development of a material capable of solving the above-mentioned problems has been successful.

[0009] That is, the present invention provides 1
(W, Ti) solid solution carbide or (W, Ti, Ta) solid solution carbide whose primary particles have a particle size of 1 to 10 μm is 10 to 30% in terms of Ti carbide, and one or two of Ni and Co 1
The gist of the present invention is a composite powder material for powder plasma welding, comprising 0 to 40% and granulated and sintered into a spherical shape.

Hereinafter, the present invention will be described in more detail.

[Action]

The point of the present invention is that the particle size of the primary particles is 1
When the thickness is 0 μm or less, Ni or Co is added as a binder of carbide particles to a solid solution carbide of W and Ti or W and Ti and Ta, and granulation and sintering are performed in a spherical shape. The reasons for these provisions are shown below.

In the present invention, the (W, Ti) solid solution carbide or the (W, Ti, Ta) solid solution carbide is used as an essential component in consideration of high hardness, high temperature stability, weldability and uniform dispersibility. Yes, considering the wear resistance in a high temperature range from room temperature to around 800 ° C. Therefore, it is also effective to apply and add other ceramic materials such as carbides, borides and oxides as auxiliary components.

(W, Ti) solid solution carbide or (W, Ti,
The reason that the amount of Ta) solid solution carbide is converted to Ti carbide is that Ti carbide is the most important component in characteristics. If the Ti carbide conversion amount is less than 10%, the effect of improving properties such as wear resistance is small, and if it exceeds 30%, the weldability is poor and it is not practical for powder plasma welding. To 30%.

Further, it is also important to define the size of the primary particles of the solid solution carbide (particles before sintering). The reason why these primary particles are set to 1 to 10 μm is to produce an almost spherical powder. If it exceeds 10 μm, spherical granulation is difficult, and if it is less than 1 μm, sinterability deteriorates and a production problem arises. Further, if the primary particles are less than 1 μm, even if the carbide has a high melting point, it is easily melted at the time of welding, and uniform carbide dispersion cannot be expected.

[0015] One or two of Ni and Co are 10 to 40%
If it is less than 10%, the binder effect at the time of sintering is small and the sinterability is poor, resulting in poor weldability. If it exceeds 40%, it tends to soften at the time of sintering and has a spherical shape. This is because manufacturing problems such as inability to hold the battery occur.

Since Ni and Co have an excellent binder effect, one or two of Ni and Co are used as essential components, but Mo, Cr, Fe, etc. may be added in appropriate amounts as other auxiliary components. .

The product particle size is preferably in the range of 45 to 180 μm. This is because it was experimentally confirmed that this range was optimal from the viewpoint of powder flowability, weldability, and uniform dispersion of the metal of the build-up metal. However, if it is less than 45 μm, there is a problem in the fluidity of the powder, and the primary particles are liable to be melted at the time of welding.

The granulated sintered powder of the present invention can be used as a welding material depending on its composition, but in many cases, it is mixed with an existing Co-based, Ni-based or Fe-based alloy powder material. To improve the characteristics. Therefore, it is possible to select a metal-based powder material according to the application and mix and use the granulated sintered powder of the present invention. At this time, the mixing ratio of the metal-based powder material is set to 10 to 90%. If the mixing ratio is less than 10%, uniformity of mixing cannot be expected. Is small.

Next, an embodiment of the present invention will be described.

【Example】

The granulated sintered powder shown in Table 1 was prepared. The solid solution carbide used had a solid solution ratio (% by weight) of 70:30.
(W, Ti) C, 50:50 (W, Ti) C, and 70: 2
0:10 (W, Ti, Ta) C. Using the granulated sintered powder, the welding materials shown in Table 2 were powder-welded to the surface of the test piece shown in FIG. 1 by powder plasma welding in one layer and two passes. , And abrasion resistance were evaluated. Table 2 shows the results. The wear resistance is shown in FIG.
The evaluation was made based on the data on loss of wear shown in FIG. FIG. 3 shows the procedure of the wear resistance test.

In Table 2, Test Nos. 1 to 3 are examples of the present invention. Among them, Nos. 1 and 3 are samples obtained by mixing 50% and 40% of commercially available Ni-50Cr welding powder, respectively. It is intended for heat and wear resistant applications. In each case, the welding workability is good, there is no crack in the welded portion, the cross-sectional structure is uniform, and as shown in FIG. 2, the wear resistance is very excellent.

Test No. 4 (comparative example) was welded using only Ni-50Cr-based metal powder and tested for comparison of wear resistance.

Test No. 5 (Comparative Example) is a mixture of W carbide (crushed powder) and 40% of Ni-50Cr-based metal powder.
This is a material obtained by a conventional method. It is thought to be due to the difference in powder fluidity, but the workability was unstable, and the bead appearance indicated that the carbide dispersibility in the welding direction was poor, and welding cracks occurred in some parts.

Test No. 6 (comparative example) was Ti carbide (crushed powder).
And 70% of Ni-50Cr-based metal powder are mixed. However, Ti carbide floats on the surface, the bead does not fit well, and the workability is poor.

Test No. 7 (Comparative Example) is a granulated sintered powder having the same composition as No. 3 (Example of the present invention), but the particle size of the granulated sintered powder product was coarsely adjusted to 75 to 250 μm. Things,
At the time of welding, it felt like foaming, and as a result, a blow hole defect was generated, and the abrasion resistance was slightly inferior to the level of the present invention.

[0026]

[Table 1]

[0027]

[Table 2]

As described in detail above, according to the carbide composite powder material for powder plasma welding of the present invention, a build-up layer having uniform and excellent wear resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a shape of a test piece used in an example.

FIG. 2 is a diagram showing wear resistance test data.

FIG. 3 is a diagram showing a procedure of a wear resistance test.

Claims (3)

(57) [Claims] 1. A (W, Ti) solid solution carbide or a (W, Ti, Ta) solid solution carbide in which the primary particles have a particle size of 1 to 10 μm in weight percent (hereinafter the same). 10-30% in terms of Ni and Co or one or two of Ni and Co
A composite powder material for powder plasma welding, comprising 10 to 40% of seeds, granulated and sintered into a spherical shape. 2. The composite powder material for powder plasma welding according to claim 1, wherein the range of the product particle size is 45 to 180 μm. 3. A powder obtained by mixing 10 to 90% of one or more of Co-based, Ni-based and Fe-based powder materials with the composite powder for powder plasma welding according to claim 1 or 2. Composite powder for plasma welding.