JPS6186075A - Build-up welding method of composite alloy and welding torch - Google Patents

Abstract

PURPOSE:To adjust accurately a component of a build-up composite alloy by making a plasma arc between an electrode and a base metal, and between a wire rod feed nozzle by each separate power source, and feeding a metallic wire rod and a non-metallic powder from a wire rod nozzle and a powder feed nozzle, respectively. CONSTITUTION:A weld metal 9 is formed by throwing a droplet 12 of a metallic wire rod 5 and a non-metallic powder 7 fed by pressure from a powder feed nozzle 6, and shifting a torch T in the direction as indicated with an arrow. In this case, a penetration rate to a base metal B, is determined by a plasma arc A1, namely, an output of a power source P1. Also, an area of a molten metal pool 8 dependes on both the plasma arc A1, namely, the output of the power source P1, and a plasma arc A2, namely, an output of a power source P2. The plasma arc A2 does not reach the base metal B, therefore, if the output of the plasma A1, namely, the output of the power source P1 is constant, a penetration rate to the base metal B is not varied, even if the area of the molten metal pool 8 is adjusted by adjusting the output of the power source P2. Therefore, the area of the molten metal pool 8 is adjusted accurately in accordance with a feed quantity of the non-metallic powder 7, and the non-metallic particle content in the weld metal is adjusted with a high accuracy.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to welding non-metallic powder and metal wire.
This technology relates to welding using a plasma arc as a heat source, and is used to build up composite alloys, that is, alloys that have a structure in which metals and non-metals coexist.

(Prior art) Conventionally, so-called composite alloys in which metal bases (hereinafter simply referred to as bases) and grains of non-metallic materials such as VC carbide (hereinafter referred to as non-metallic grains) are dispersed are deposited by overlay welding. Various methods have been proposed.

The most typical of these are the PvllQ welding method or the plasma powder overlay welding method, but in both cases, the actual value and target content of nonmetallic particles in the overlay welding method are There is a problem that there is a large difference between the values of t and t.

For example, 1r, Figure 5, 1-1 normal 1k-j
IG welding method (/Talinatka”sark welding/A
) k As a precaution, place the spout (opening) near the IIG welding torch (a) and remove the welding power source (
PN2) A constant MIG arc 1. Form 1 by t'J
The molten metal Mt supplied from the IIGf8 contact torch was drilled and protected by a VC.
4 trillion rt droplets + fJ due to the melting of the weld line
The second is a method in which the nonmetallic powder material is completely charged from the feed nozzle to form a weld metal smoke pattern.

4th, the one shown in Fig. 6 is a method using the so-called plasma powder overlay welding method.
A plasma arc (fA) ignited through an arc restraint nozzle (W) between This is a method in which a mixed powder (n) of metal powder and non-metallic powder is poured into a pond (-) to form a bath-welded metal (Δ). The metal paulownia materials that are sent to the designated IC to form the primary kinro base are called general VC base goods, and those in the form of wire rods are metal wire rods.

What about metal powders in powder form, non-metallic powder materials that are fed to form non-metallic particles that are dispersed throughout the base? It is called non-metallic powder. ) By the way, no matter which welding method is used, the ratio of the respective feeding amounts of the base material and non-metallic powder, and the actual composition ratio of the metal base and non-metallic particles in the weld metal mold formed after welding. It is necessary to reduce the difference in f, and for this purpose, the following three conditions are necessary.

[1] In order to suppress the decrease in the non-metallic particle content due to dilution of the molten weld metal, the penetration rate into the base metal should be kept to a minimum.

] Non-metallic powder is melted by arc heat, forming molten metal/
1i In order to prevent alloying in IVC, the time during which the non-metallic powder is exposed to the arc must be kept to a minimum.
[3] In order to capture the flying non-gold F8 grains with a high yield, it is necessary that the weld metal pond formed by welding the seven base materials has a sufficient area and depth. Considering the conditions for conventional welding methods, the MIG injection method generally has a low penetration rate, which makes it difficult to produce a composite alloy with the desired composition. If the heat input sound is reduced in order to reduce the total size of the melt, there is a problem that the area and depth of the melt pond will become smaller. In addition, in the mixed powder plasma method, penetration is good, but during welding, powder with a constant acid content ratio (metal: non-metal) is always fed.For both Kn metal powder and non-metal powder, It is necessary to take into account the complex relationships between specific gravity, particle size distribution, shape of one particle, etc.
Adjustment of powder materials is complicated, and under the condition that metal powder and non-metal powder are supplied together, is it possible to melt the entire set of powders using a single heat source with sufficient VC while bathing the non-metal powder? Since there are always conflicting conditions that the degree of welding must be suppressed, there is a problem that the range of welding conditions is narrow.

Also, in the method using plasma arc, are there other metal powder and non-metal powder materials? feeding from a separate nozzle I;
There is a method of welding with a single arc, but although this method can solve the problem of acid content ratio, as long as a single arc is used,
The above problem of melting conditions cannot be solved.

It should be noted that the conventional plasma arc torch used for the above purpose uses a single plasma arc, and therefore has the same problems as mentioned above.

(Problems to be Solved by the Invention) The method of the present invention was developed to improve the above-mentioned conventional problems by applying a so-called double arc to overlay welding of composite alloys.

Precise (accurate) K in the composition of the components of the overlaid composite alloy.

Moreover, the present invention aims to provide a method for easily adjusting VC.

Note 1: The present invention relates to overlay welding of 0 alloy.

Nonmetal grain content in weld metal? Be precise (accurate).

And a mechanism for easy adjustment? I have it.

A plasma arc torch that has a mechanism for simultaneously feeding a few types of non-metallic powder? This is what we are trying to provide.

(Problem? Determined means to solve the problem) Is the overlay welding method for composite alloys according to the present invention applicable between the non-consumable electrode and the welding base material, and between the non-consumable electrode and the wire feed/slip? By connecting to a separate welding power source, a non-consumable electric current is generated between the welding base metal and the gap between the non-consumable electrode and the wire feed nozzle, and the wire rod and powder are fed from the wire feed nozzle. Non-metallic powder such as carbide from the supply nozzle? This method is characterized by forming a composite alloy consisting of a structure in which non-metal particles are dispersed in a metal matrix while feeding the weld metal to the weld metal.

In addition, the welding torch used in the method of the present invention has a non-consumable electrode and an arc restraint nozzle I arranged in the center, and around this center part, electrically connected Only an insulated wire feed nozzle, powder and inert scum or inert force? The device is characterized in that a required number of powder-gas nozzles I for feeding are arranged at required intervals.

(Function) The method of the present invention uses arcs that can be independently controlled in two systems to adjust the melting conditions of the base material and base material. In summary, the torch of the present invention improves the quality and component accuracy of composite alloy overlay layers by controlling them independently of each other. One type can be fed at the same time from one nozzle.
Also.

This prevents eccentricity of the arc by equalizing the influence of the inert gas flow ejected from each nozzle on the arc.

(Example of Actual Foil) Figure 1 is a schematic explanatory diagram of the welding method according to the method of the present invention, in which a molten metal pool is formed using two arcs, so-called double arcs, each of which can fully control the output independently. Welding metal of composite alloy by adding non-metallic powder? It is something that forms.

That is, the non-consumable electrode 1 and the base material B, and the non-consumable electrode 1 and the wire feeding nozzle 3 are electrically connected to the welding power sources P1 and P2, respectively, as shown in the figure, and the metal wire 5 is connected to the wire rod. It is fed by the feeding nozzle 3. In this circuit, between the non-consumable electrode Summer and the base material B, and the non-consumable electrode! and between the full thickness wire 5.

An inert force is introduced into the atmosphere, and plasma arc A1 and plasma arc A2 are generated through arc restraint nozzle 2. The metal wire 5 is fed in the ignited state, and the droplets 12 generated by the melting of the metal wire 5 and the non-metal powder 7 ? Transferring the torch Ti in the direction of the arrow while charging it into the molten metal pool 8, welding metal If4! l form. (The melting cap metal pond 8 is protected by an inert shielding gas 1lVc supplied from the shielding cap 10.) In this case, the penetration rate into the base metal B is the plasma arc A1
．． Therefore, it is determined by the output of the welding power source PI.

Just in case, the area of molten metal pool 8 is plasma arc Al.

The output of the welding power source PI and the plasma arc A2,
Therefore, it depends on both the output of the welding power source P2. (P
The output of I heats the molten metal pool 8, and the output of P2 approximately determines the melting rate of the metal wire 5, and therefore the amount of molten metal supplied to the molten metal pool 8 per unit time. ) Since the plasma arc A2 does not reach the base metal B, if the output of the plasma arc A1, and therefore the output of the welding power source P1, is constant, even if the output of the welding power source P2 is adjusted and the area of the molten metal pool 8 is adjusted, the base metal will not reach the base metal B. The penetration rate into material B remains unchanged. From this, the supply of nonmetallic powder 7 is 11tVC.
Accordingly, it becomes possible to precisely (accurately) adjust the total area of the molten metal pool 8 (VC), and it is possible to adjust the nonmetallic particle content in the composite alloy welded gold silk with high precision.

As for the wire feed nozzle 3 and the powder feed nozzle 6, it does not matter if either or both of these nozzles include the plasma arc torch TVCM 1t or not.

Figure 2 is an enlarged illustration of the main parts of the e-plasma arc torch mentioned above, and shows the non-consumable electrode 1 (!: arc restraint/placed in the center hole of the cell 2, 111 goods feeding nozzle 3) A powder-gas nozzle 4 (a nozzle for delivering powder material and an inert gas or only an inert gas) is arranged around the arc restraint nozzle 2.

In addition, it is insulated from the #j goods feeding/nozzle 3-piece talkie body. Also, the center line of #goods feeding nozzle 3 is.

Below the arc restraint nozzle 2, it intersects the torch center nozzle line at an intersection point PI with an intersection angle of 45°, and the powder
Intersection point Pt with ICJ1+j in the middle of the nozzle 4, VC'F below the arc restraint nozzle 2, and the ICr line in the torch.
intersect at an intersection angle of 45° at vc. Also, the above intersection point P.

It is located approximately 10 mK above the intersection point P2. Torch centerline and powder-gas nozzle4. Or wire feeding nozzle 3
What is the positional relationship between the intersection points P, ,P, of each extension line of the center line? However, if this positional relationship is reversed, the non-metallic powder 7 will come into contact with, adhere to, and melt the arc anode point on the metal wire 5 and its vicinity, disturbing the arc A2 and causing the metal wire 5
This is to be completely avoided since it interferes with the normal dissolution of the water.

Moreover, the powder-gas nozzle 4 is connected to the non-metallic powder feeding path 4I inside the torch, and both of the powder-gas nozzles 4 have 0 base 'hV'.
c is connected to an external water supply source 43Vc. Powder - inert gas flow l-1/- delivered from gas nozzle 4
It flows out from the molten metal nozzle (cap 10), functions as a 7-metal gas 11, and melts the metal wire 5 into a molten metal pool 8.
The molten metal and non-metal powder 7 are protected over a range from formation to solidification.

Figure 3 shows the arrangement of the nozzles on the end face of the torch. It is an opening.

Nao, the number of powder gas nozzles 4 is one in the embodiment (third example).
In Figure), 6 nozzles are arranged at the required intervals around the nozzle 2, and during welding, the tungsten carbide powder is fed under pressure from the required number of powder-gas nozzles using completely inert gas, and the non-metallic powder is fed. Powder-gas nozzles that were not used for this purpose simply delivered all of the inert gas. Further, the flow rate of the inert gas in each powder-gas nozzle was made equal for all nozzles.

In the above embodiment, although there are a plurality of powder gas nozzles 4, different kinds of non-metal powders, or maybe non-metal powder or metal powder? This is to make it possible to simultaneously feed one type of ink using the I nozzle. Also, regarding the number of nozzles.

One can be used, but it is preferable to have multiple. In that case, an equal amount of gas is removed from all the nozzles to equalize the shadow V cast on the arc by the inert gas flow ejected from each nozzle and completely prevent eccentricity of the arc. Inert gas? The powder carrier gas flow rate per nozzle (3 to 617 minutes) that needs to be delivered is typically required.

/- Total flow rate of the shield gas (15 to 201/min) 7 If the powder carrier gas is taken as the standard, 2 pipes will not have enough vtfl as a shielding gas, and 7 pipes will have an excessive flow rate as a shielding gas. 3 to 6 bottles because it is uneconomical? Most preferably, it is used.

Figure ':
Connected to fM material feed/zunozu.

The inert force supply device @ 13 is connected to the pipe T and the powder feed device 14i by piping. In addition, the powder feeding device 14 is connected to the torch T (powder feeding nozzle 6) by K piping, and through this piping non-Kanasu powder (7
) is supplied with torch TIc.

- The stem is made of carbon steel (825C) with a thickness of between 50
) 6A FA and tungsten carbide powder (particle size part ++45 horn 7U) for welding of 1tiiMi+c, JIS standard Y308 applicable chemical, and tungsten carbide powder (particle size part ++45 horns 7U) were used as total welding materials. Perform welding, width 100fi, length 200fi for each condition
A weld metal of yrs was formed. Note that the number of overlay layers was one.

Table 1 Tungsten carbide build-up welding conditions In order to investigate the tungsten carbide content in the composite alloy obtained in the above test, the build-up layer was cut out by electrical discharge machining and its specific gravity was measured. The results are shown in Table 2.

Table 2 Result of Specific Gravity Measurement of Overlay Layer The welding test was performed three times for each target content value in Table 2, and five specific gravity test pieces (lcfn square) were extracted and measured each time. The fixed value on the specific gravity side is the average value (the number of data for each target value is 15).

Converted from specific gravity (refer to the conversion formula below) The set carbon steel carbide content shows a total error of 4 to 5% from the target value, but since the error in the case of the conventional technology mentioned above is 10 to 20, A much smaller and practical VC in comparison.
(This is not a problem.

(Conversion formula) P: Tungsten carbide content (%) t: Specific weight of composite alloy overlay weld metal: Specific gravity of base material (79) C: Specific gravity of tungsten carbide (16,8) (Effect of invention) For those who did not invent 1P According to the composition groove of the overlaid composite alloy [
It produces an excellent mental effect that can be easily adjusted.

1. The welding torch used in the method of the present invention.

The content of non-metallic particles in the weld metal can be precisely and easily adjusted, as well as multiple types of non-metallic powder (or non-metallic powder and metallic powder)? What is the excellent effect of a whistle that can simultaneously feed the gas and prevent eccentricity of the arc by equalizing the influence of the inert gas flow ejected from each nozzle on the arc? It is something to play.

[Brief explanation of drawings]

Figures 1 to 4 show examples of the present invention, Figure 1 is a schematic explanatory diagram of the method of the present invention, and Figure 2 is an enlarged end view of the main part of the welding toe fist used in the method of the present invention. Figure 3 is a partially omitted bottom view of the main parts of the torch, and Figure 4 is the welding system of the present invention method. FIG. FIG. 5 and FIG. ff16 are schematic explanatory diagrams of the conventional MIG welding method and the plasma 8-body overlay welding method. I...Non-consumable electrode, 2...Arc restraint nozzle/l/
43... Line feeding nozzle, 4... Powder-gas nozzle. 5. Metal wire, 6. Powder feeding nozzle, 7.
・Nonmetal powder, 10.../- Rudcamp, T torch, PI...Ill P2 ・Power source.

Claims (2)

[Claims] (1) Connect the areas between the non-consumable electrode and the welding base material and between the non-consumable electrode and the wire feeding nozzle to separate welding power sources, and It consists of a structure in which non-metallic particles are dispersed in a metal base while generating a plasma arc in each gap while feeding metal wire from the wire feeding nozzle and feeding non-metallic powder such as carbide from the powder feeding nozzle. , a method for overlaying a composite alloy, characterized by forming a composite alloy as a weld metal. (2) A non-consumable electrode and an arc restraint nozzle are placed in the center, and around this center are a wire feed nozzle that is electrically insulated from the torch body that feeds the metal wire, and a wire feed nozzle that feeds the metal wire and an inert A composite alloy overlay welding torch characterized in that a required number of powder-gas nozzles for feeding only gas or inert gas are arranged at a required interval.