JPH0446696A - Wire rod for welding - Google Patents

Abstract

PURPOSE:To manufacture a wire rod having high weldability by forming metal powder mixing the specific quantity of metal oxide, etc., under high temp. and high pressure and executing wire drawing after annealing. CONSTITUTION:At the time of manufacturing the wire rod for welding, the metal powder mixing 0.01 - 15% one or more kinds of metal oxide, fluoride and carbonate is formed under high temp. and high pressure of temp. condition of lower than decomposition temp. of the compound. By this method, as the wire rod stably contains one or more kinds of oxide, fluoride and carbonate according to necessity and becomes supplying source of these compounds in the wire rod itself, in the case of using as wire for gas shield arc welding, weldability of improvements of arc stability, spattering reduction and bead formability and cracking resistance, etc., can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wire rod for general welding, and in particular, it can be used as a wire for MAG welding and other gas-shielded arc welding to provide arc stability and reduce the generation of spatter. It has excellent effects on improving weldability, such as reducing

[Conventional technology]

As shown in FIG. 1, the most common method for manufacturing welding wire is to roll and wire-draw a melted ingot or continuous casting billet.

By the way, the presence of compounds such as metal oxides, fluorides, and carbonates improves arc stability in welding, reduces spatter, lowers the hydrogen content of the weld metal and improves cracking resistance. It also has the effect of improving the bead shape, but wire rods using the above-mentioned cast material contain oxides (Sin, Mn05A Il t Ox, etc.) as inclusions.
Although it remains, it does not always exist stably, and there is a problem of specific gravity difference, so we actively remove oxides,
It has not been possible to incorporate compounds that improve weldability, such as fluorides and carbonates, at the casting stage.

Therefore, in order to improve weldability, in the case of coated arc welding rods, these compounds are added to the coated side according to various purposes. However, in the case of gas-shielded arc welding rods, there is no source of addition of these compounds for the reasons mentioned above, so spatter is often generated during welding and arc stability is lacking.

Recently, a Cr--Co filler rod in which carbides are mainly left in the rod using a powder metallurgy method has been announced (Japanese Patent Application Laid-Open No. 62-6794).

For example, 55% Cr,
High alloy powder such as Co45% and ceramic powder are
It is a filler rod that is blended at an extremely high ratio of 0 to 80%, preferably 50 to 80%, and solidified into a rod shape by energization and sintering, and is intended to improve the properties of overlay by adding ceramic powder. However, this product uses metal powder, which is a difficult-to-process material, and ceramic powder, which is difficult to process, is used for 20 to 30 minutes.
Because it is added in a large amount (80%), it is manufactured using an inefficient manufacturing method such as sintering using electric current, and cannot be rolled or wire-drawn, making it a bar instead of a wire.

[Problem to be solved by the invention]

As mentioned above, since conventional welding wire rods use cast materials, metal oxides, fluorides, etc. are stably contained in the wire rods.
Currently, it does not contain carbonates or the like, and is added from the coating agent by covered arc welding, and the filler rod is also rod-shaped and not a wire rod.

An object of the present invention is to obtain a welding wire material that stably contains compounds such as metal oxides, fluorides, and carbonates in accordance with the purpose, and which can be used as a gas shield welding wire. It becomes a source of the above compounds by itself, improving arc stability, reducing spatter, improving vortex flow, improving bead shape, and reducing the amount of hydrogen in the weld metal to improve cracking resistance. etc. will be effective.

Of course, this welding wire also exhibits the effect of improving weldability when used as a core wire for covered arc welding.

[Means for solving the problem] One or more types of metal oxides, fluorides, and carbonates at 0°01~
The desired welding wire can be obtained by molding a 15% mixed metal powder under high temperature and high pressure conditions at a temperature lower than the decomposition temperature of the compound, annealing, and then wire drawing.

[For production]

In this case, by setting the mixing amount of the above compound to 0.01 to 15%, hot extrusion moldability is improved and rolling and wire drawing are possible. It is possible to obtain a welding material with excellent weldability that contains one or more types of carbonates, and it is also possible to obtain a welding material with excellent weldability that contains one or more types of carbonates.Also, it is possible to obtain a welding material with excellent weldability that contains one or more types of carbonates.In addition, the raw material powder is processed at high temperature and high pressure at a temperature lower than the decomposition temperature of the metal oxides, fluorides, and carbonates added. By solidifying and forming, the above-mentioned compound can be stably contained in the wire rod, as well as good hot formability.

Since the welding wire rod of the present invention acts as a wire itself as a source of metal oxides, fluorides, carbonates, etc., it can be used for gas-shielded arc welding, etc. to improve arc stability and reduce spatter. , it is possible to improve the bead shape, improve the cracking resistance of the weld metal, etc.

〔Example〕

FIG. 2 shows the manufacturing process of the welding wire of the present invention.

First, in the raw material blending process, the required metal powder and one or more types of metal oxides, fluorides, and carbonates are mixed in a predetermined manner according to the purpose. The high temperature and high pressure conditions lower than the decomposition temperature of the above compounded compound to be enclosed, that is, the temperature at which metal oxides, fluorides, and carbonates decompose, are in the range of about 898 ° C. to 2500 ° C. High temperature and high pressure in low temperature conditions,
For example, the compound CaCoz (Note) decomposes at 898°C, and the compound Na decomposes at 1705°C at 870°C.
If F (note), it is formed into a billet of 20 φ x 1.5 M by hot extrusion at 4000 atm, for example, at 1250°C (Note, Combined Wave Science and Chemistry Dictionary, 3rd edition expanded edition), and then annealed. After annealing at, for example, 720° C. for 15 minutes, the wire rod is subjected to the next rolling process to obtain a welding wire rod of, for example, 5.5φ19m. This wire is then drawn to a predetermined diameter to produce various products.

In addition, in the present invention, the mixing ratio of metal oxides, fluorides, and carbonates is limited to 0.01 to 15%.
If it is less than 1%, the desired weldability improvement effect will not be achieved (
Moreover, if it exceeds 15%, high-temperature, high-pressure formability deteriorates, and there is a risk of cracking in the billet.

Next, performance test results will be shown for examples of the present invention as well as comparative examples.

Tables 3 (1) to (7) show examples of MAG welding, and Table 4 shows examples of covered arc welding.

Table 1 shows the MAG welding test conditions, and Table 2 shows the covered arc welding test conditions.

In the test results shown in Table 3, the billet formability was determined by using a raw material sealed in a sheathed tube (3t x 60φ x 170mm) under the high temperature and high pressure conditions listed in the same table.
It was determined by molding into a M billet and inspecting the billet for defects such as cracks.

Regarding weldability, the amount of hydrogen was measured according to JIS Z3118 and was 2.0 mjl! /100g was considered good.

Note that Examples Nf164 to Nf124 were omitted because they were made of austenitic stainless steel and the amount of hydrogen did not matter. Arc stability is considered good when the voltage at which the wire can weld without stinking into the base metal is less than 18V, the amount of spatter generation is considered good when it is less than 2.0g/min, and the bead formation is smooth without becoming convex. It was considered good to be.

As for the test wires in Table 3, a billet of 20φ x 1.5M was drawn into a coil of 1.2φ by a predetermined method to conduct the test using the MAG welding method. Note that although the test wire was not plated with Cu, the same result would be obtained even if it was plated with copper.

Judgments in the coated arc welding tests shown in Table 1 are made by visually and feelingly comparing the arc stability and bead shape with comparative examples, and the amount of hydrogen is determined based on the measurement results according to JIS Z3118. Judgment was made based on whether it was lower than that of the comparative example.

The test wire material was a billet formed as described above, which was molded using a prescribed method to a size of 40φ x 400j! After drawing and cutting the wire, it was used as a core wire for coated arc welding.

As shown in Table 3 (1) to (7), the weldability of the welding wire rod of the present invention is significantly improved compared to the conventional comparative example.

Furthermore, as shown in the same table, when adding any type of metal compound, if 15% is added, defects such as cracks will occur in the billet during forming, and if it is less than 0.01%, it will have no effect on weldability. poor.

A similar tendency was observed in the test results when used for coated arc welding core wire in Table 4.
It has been shown that addition of ~15% is effective.

In addition, in these examples, raw materials such as iron powder and Fe-Mn were mixed with the metal powder as they were, but
It goes without saying that the same effect can be obtained even if the components excluding metal oxides, fluorides, carbonates, etc. are pre-dissolved and pulverized.

〔Effect of the invention〕

The welding wire rod of the present invention is a wire rod, and furthermore, it stably contains one or more of metal oxides, fluorides, and carbonates as required, and the wire itself serves as a source of these compounds, so it can be used as a gas shield. When used as an arc welding wire, it improves arc stability, reduces spatter, improves swirl flow to improve bead shape, lowers the hydrogen content of weld metal and improves cracking resistance. In addition to significantly improving weldability by reducing spatter, it can also be used as a core material for coated arc welding, and can achieve similar effects.

[Brief explanation of the drawing]

FIG. 1 is a manufacturing process diagram of a welding wire rod by a casting method, and FIG. 2 is a manufacturing process diagram of a welding wire rod of the present invention. Applicant: Sumikin Welding Industries, Ltd. Applicant: Sumitomo Metal Industries, Ltd. Uso S)

Claims (1)

[Claims] (1) One or more types of metal oxides, fluorides, and carbonates with 0.
1. A welding wire rod, characterized in that a metal powder containing a mixture of 0.01 to 15% is formed under high temperature and high pressure conditions at a temperature lower than the decomposition temperature of the compound, annealed, and then drawn.