JPS5846398B2 - welding wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding wire used in molten metal arc welding such as MIG, submerged arc, and carbon dioxide arc welding, which has excellent feedability, rust prevention, and workability.
It is an object of the present invention to provide a welding wire capable of obtaining a weld metal with a low hydrogen content.

Generally, a wire made of bare metal wire is used in melt electrode arc welding.

These wires are coated with copper on their surfaces to prevent rust and improve electrical conductivity.

Conventionally, this type of wire has been manufactured based on its components as well as the physical and chemical properties of the wire surface, which are important for weldability, especially welding workability and feedability, as well as the mechanical and chemical properties, appearance, and storage properties of the deposited metal. It is said that this is a major factor that affects the quality of special orders such as, and that the surface must be clean and free from rust and oil.

However, conventional welding wires have poor rust prevention properties and have poor feedability due to the large contact resistance when passing through the chip break or contact jaw, resulting in a large amount of spatter, which is a serious problem. There were problems such as causing severe welding defects.

As a solution to these problems, welding wires have recently been published that have a surface coated with a small amount of lubricating oil to the extent that it is not harmful to the welding results.

This welding wire has good rust prevention properties and can produce good welding results when welding mild steel, etc. However, when welding high-strength steel, etc., the hydrogen content in the weld metal becomes significant due to lubricating oil adhering to the surface. It has the disadvantage that it cannot be used because of the increase in the size of the coating, and at the same time, it has the disadvantage that sufficient antirust properties cannot be obtained unless it is applied or adhered to in a certain amount.

The present invention has solved the above-mentioned problems and drawbacks, and the gist thereof is to use a lubricating substance consisting of a higher fatty acid having 8 or more carbon atoms and an alkali metal salt of the higher fatty acid having 8 or more carbon atoms. Welding characterized by drawing a wire using a lubricant diluted with a volatile solvent having an affinity for wire, W=DX (2,5~8
3), [where W is the amount of lubricant substance deposited per unit surface area of the wire (mP/rn2), and D is the wire diameter (mal
) There is f.

〕,It is in. Examples of the lubricating substance used in the present invention include soap buttons and higher fatty acids having 8 or more carbon atoms, preferably 12 to 18 carbon atoms.

Soaps include alkali metal salts of higher fatty acids having 8 or more carbon atoms, such as oleic acid, stearic acid, and valmitic acid, as well as salts of resin acids and naphthenic acids.

The above lubricating substances may be used alone or in combination with water, acetone,
Alcohols, ketones, esters, alcohol esters, ketone esters, ethers, etc. have an affinity for the lubricating substance, that is, they dissolve or partially dissolve the lubricating substance to form an emulsion. It is diluted with a volatile solvent to a concentration of about 4 to 17 wt%, and if necessary, sodium carbonate is added to adjust the pH to 7, 5 to 10.0. This solution is used as a lubricant during wire drawing. be done.

The adhesion amount (w) of the lubricant substance is expressed as D per unit surface area of the wire.
The reason for choosing X(2,5-83) is as follows.

In other words, when the amount of adhesion is less than 2.5 D (mP/m" wire), the effect of adhering the lubricating substance on the wire surface in terms of rust prevention and feedability is not recognized, and chips are formed during welding. Or, there is a problem such as wearing out the contact jaw, and the 83D (mV/m2 wire)
If the amount is too high, the hydrogen content in the weld metal will increase, making it impossible to obtain a high-quality weld, and if it is excessive, the wire will become sticky, attracting impurities, causing damage such as chips, and damaging the feed roller and wire. This is because slips occur between the two, resulting in a decrease in workability and electrical conductivity, and making it difficult to wind in alignment during the production of twirls.

As for the amount of lubricant to be applied to the surface of the wire, it is also possible to apply the lubricant by impregnating it with a die, sponge, felt, etc. and applying it to the wire.

The composition of the wire may be one commonly used in melt electrode arc welding such as MIG, submerged arc welding, and carbon dioxide arc welding.

An embodiment of the present invention will be described below.

Example 1 A lubricant base containing 9 parts by weight of a lubricating substance consisting of 20 parts by weight of a commercially available soap (main component sodium nioleate) and 80 parts by weight of oleic acid, with the remainder being substantially water, was prepared. Prepare lubricants of various concentrations with a pH of 9 by diluting with
A carbon dioxide arc welding wire A having a diameter of φ was manufactured.

Example 2 Alkali metal salt of higher fatty acid (sodium stearate) 2
A lubricant containing 10 parts by weight of a lubricating substance consisting of 0 parts by weight and 80 parts by weight of palmitic acid, the balance being water, was mixed with water to prepare emulsions of various concentrations with a pH of 9, and each emulsion was used. The wire was drawn to produce a 1.2φ carbon dioxide arc welding wire A'.

Prepare a lubricant base containing 9 parts by weight of the above-mentioned lubricant substance and the remainder being substantially water, dilute this with water to prepare lubricants of various concentrations, and use each lubricant to prepare a wire. Wire C for carbon dioxide arc welding with a diameter of 1.2 φ was produced by drawing.

Example 4 A lubricant base containing 10% more of the above lubricating substance and the remainder water was prepared, mixed with water to prepare emulsions of various concentrations, and wires were drawn using each emulsion. A 1.2φ carbon dioxide arc welding wire D was manufactured.

Various tests were conducted on the various wires obtained in each example, and the test results will be explained below.

Note that lubricating substances (
To measure the adhesion amount of soap and oleic acid (sodium stearate and pallic acid), the weight of a dried wire is measured, and then the wire is immersed in an ether solution to extract the lubricating substance, and then dried. The weight of the wire was measured again and the difference was determined as the amount of lubricant applied.

Therefore, in this specification, the amount of the lubricant substance attached means the amount of only the lubricant substance remaining on the wire surface after the lubricant is dried, that is, the amount after drying.

[Relationship between amount of lubricant deposited and wire productivity] The spool winding productivity index of the obtained welding wires A, A', and C9DFc was measured, and the results shown in FIGS. 1 and 1 were obtained.

As is clear from these figures, if the amount of lubricant deposited at 0 is taken as 100%, in the case of a 1.2φ wire, it increases as the amount of deposit increases and reaches a maximum at about 50 mV/m2 wire surface area. It can be seen that as the amount of adhesion increases further, it begins to decrease, and when it exceeds about 100 mP/m2 wire, it decreases to less than 100φ.

This is because if the amount of adhesion exceeds 9, the wires will slip, making it difficult to wind them in alignment.

Therefore, from the point of view of the spool winding productivity index, it is preferable that the amount of unattached lubricant substance is 100 mr/m'' wire or less when the wire diameter is 1.2φ, that is, the coefficient in the above formula is 83 or less.

[Relationship between the amount of lubricant deposited and wire feedability] Next, welding wires A, A',
C and D were used to measure wire feedability when welding in a low current range and in welding in a high current range.

Figures 2 and 8 show the relationship between the deposit amount and the feed motor terminal voltage (wire feedability) when the welding current is 150A, and Figures 3 and 9 show the relationship when the welding current is 250A. show.

In each case, carbon dioxide arc welding was performed using a 1.2φ CO2 wire.

As is clear from these figures, even in the low current range,
Also, even in the high current range, the amount of lubricant attached is 2 to 4.
When the voltage exceeds the m〃h'' wire, the feed motor terminal voltage decreases rapidly.

That is, it can be seen that the wire feedability is significantly improved.

Therefore, it can be seen that in order to improve the wire feedability, it is necessary to make the amount of the lubricant adhered to at least 3 mfl'm2 wire or more, that is, the coefficient in the formula needs to be 2.5 or more.

[Relationship between the amount of lubricant deposited and the amount of hydrogen in the weld metal]

The diameter is 1.2φ, and its chemical composition is c:o, os%, Mn.
: 1.60φ, Si: 0.81%, P: 0.011 yen,
Welding wire A is made by adhering the above lubricating substance to a wire consisting of S: 0.012% and residual Fe.

Using A' and C2D, carbon dioxide arc welding was performed under conditions of 250 A and 25 V, and the hydrogen content in the deposited metal was measured to determine the relationship between the amount of lubricant deposited and the hydrogen content.

The results obtained are shown in FIGS. 4 and 10.

As is clear from these figures, there is a nearly proportional relationship between the adhesion amount and the hydrogen content, making it possible to apply the wire to all steel types.
In order to obtain high-grade weld metal, the hydrogen content in the weld metal must be 2cc/100? If the wire diameter is 1.2φ, the amount of lubricant attached is 1.
It can be seen that a value of 00 mff/m2 wire or less is preferable.

[Relationship between the amount of lubricant deposited and arc stability] Furthermore, when welding wires A, A', and C2D were used, the number of short circuits during welding on the flat bead was measured, and the results were as shown in Figures 5 and 11. The results were obtained.

In the figure, 1 shows the results for a welding wire with a lubricant coating amount of O, and 2 and 3 each show the results for a welding wire with a coating amount of 45 mf.
? The results are shown for welding wires of /m2ff and 100 mVrn2 wires.

As is clear from these results, the amount of lubricant deposited is 10
It can be seen that below 0 mf/m2 wire, there is almost no effect on the stability of the arc, and the current conductivity is also good.

[Relationship between the amount of lubricant attached and rust resistance]

Further, welding wires A, A', C, and D of the present invention and welding wire B, which has a conventional mineral oil-based lubricant adhered to its surface, were tested for their rust prevention properties.

The results are shown in FIGS. 6 and 12.

In the figure, A, A', and C9D show the results for the welding wire of the present invention, and B shows the results for the welding wire using a conventional mineral oil-based lubricant.

The test method was to alternately expose the wire to conditions of a temperature of 50°C and humidity of 90% and to conditions of a temperature of 30°C and humidity of 50%, 12 times in 24 hours, and then observe the wire. It was determined that

Judgments were made by observing the surface condition under 10x magnification using a magnifying glass and making judgments based on the following criteria.

As is clear from the figure, the welding wire of the present invention shows almost no rust even when the amount of lubricant attached is extremely small, compared to welding wire coated with a mineral oil-based lubricant. It can be seen that the anti-corrosion property is extremely excellent.

The above was a test on a 1.2φ wire, and the results show that for a 1.2φ wire, a wire with an adhesion amount of 3 to 100 mVrn2 is overall superior, but the optimum range for this adhesion amount is As a result of examining various wire diameters, it was found that there is an appropriate adhesion film thickness than the absolute value of adhesion amount.
It has been found that the range is expressed by the amount of deposition per unit wire surface area, as given by the equation W=DX(2,5-83).

Therefore, in the case of a wire other than 1.2φ, the same effect as described for the case of a 1.2φ wire can be obtained as long as the amount of adhesion is within the range that satisfies the above formula.

[Relationship between wire diameter and amount of lubricant deposited] Welding wires of various diameters were manufactured using the various lubricants mentioned above, and the rust prevention and feedability required for weldable wires were obtained in the same manner as above. When we determined the range of the amount of lubricant deposited per unit surface area of the wire that would yield good results in terms of productivity and the amount of hydrogen in the weld metal, we obtained the following results.

The above table also shows the amount of lubricant applied per unit surface area of the wire converted into the amount of lubricant applied per 10 kg of wire.

As is clear from the table, the amount W of the lubricant deposited per unit surface area of the wire that yields good results increases in proportion to the wire diameter;
The amount of adhesive is 0.013 to 0, regardless of the wire diameter.
．． It is constant at 424P.

From these results, a relational expression between the amount of adhesion and the wire diameter was found, and it was found that the amount W of the lubricant adhered per unit surface area of the wire had a relationship of DX (2, 5 to 83).

Therefore, for each wire diameter, the formula that expresses the amount of lubricant deposited from 0.013 to 0.424 P per 10 kg of wire weight as the amount of deposited per unit area is W =
It can be said that DX(2,5-83).

As is clear from the above description, according to the present invention, a lubricant substance is added to the surface of a welding wire used in welding arc welding using the formula W=DX(2,5-83) [where W is The amount of lubricant applied per unit surface area of the wire (mfi
1m” wire), D is the wire diameter (11Lm)]
By depositing only a satisfactory amount of hydrogen, welding wire feedability, rust prevention, and welding workability can be significantly improved, and weld metal with an extremely low hydrogen content can be obtained, among other excellent effects. is obtained.

[Brief explanation of drawings]

Figures 1 and 7 are graphs showing the relationship between the amount of lubricant deposited and the spool winding productivity index of welding wire;
Figures 3, 8 and 9 are graphs showing the influence of lubricating substances on wire feedability in the low current range and high current range, and Figures 4 and 10 are graphs showing the effects of lubricating substances on wire feedability in the low current range and high current range. Graphs showing the effect of lubricating substances on the hydrogen content of weld metal; Figures 5 and 11 are graphs showing the effect of lubricating substances on arc stability; Figures 6 and 12 show the effects of lubricating substances on rust prevention. FIG. 1... Welding wire with no amount of lubricant attached, 2...
Welding wire with a lubricant coating amount of 45 mr/m2 wire, 3... Welding wire with a lubricant coating amount of 100 mP/m2 wire, A, A', C, D... Welding of the present invention Wire, B: A welding wire coated with a conventional mineral oil-based lubricant.

Claims (1)

[Scope of Claims] 1. A lubricating substance consisting of a higher fatty acid having 8 or more carbon atoms and an alkali metal salt of the higher fatty acid having 8 or more carbon atoms is diluted with a volatile solvent that has an affinity with the lubricating substance. A welding wire, characterized in that the wire is drawn using a lubricant, and the lubricant substance is adhered to the surface of the wire in an amount represented by the following formula. W=DX(2,5-83) [However, W is the amount of lubricant substance deposited per unit surface area of the wire (ms'/m2 wire), and D is the wire diameter (diameter). ]