JPH08155671A - Welding wire - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a welding wire having a small coefficient of friction and a small change over time, which is applied to the surface thereof and has a good feedability. [Structure] A vegetable oil having an iodine value of less than 100 was applied to the surface of the welding wire so that the amount of oil applied was 1 to 300 when the weight of the welding wire was set to 300 ppm or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding wire used for gas metal arc welding, for example.

[0002]

2. Description of the Related Art For example, in gas metal arc welding using a welding wire, a diameter of 0.
A welding wire of about 8 to 3.2 mm is fed to the welding portion through a flexible conduit tube having a length of 3 m or more, a welding torch, and a welding tip by using a wire feeding motor or the like. Therefore, the welding wire is fed while coming into contact with the inner surfaces of the conduit tube, the welding torch, and the welding tip, and frictional force due to contact resistance is generated between these wires. When welding, it is necessary to feed the welding wire smoothly and continuously in order to stabilize the arc and prevent the occurrence of welding defects.Usually, welding wire with oil on the surface is used. To be done. As the oil applied to the surface of the welding wire, generally, a feedability improving oil whose main component is mineral oil, which has a large friction coefficient with a small change over time and a large friction coefficient, and an inexpensive animal oil, which has a high iodine value and a small friction coefficient, are used. Feedability-improving oils containing mainly vegetable oil and vegetable oil are known.

[0003]

Among the above-mentioned delivery-improving oils, the delivery-improving oil containing mineral oil as a main component does not change with time as described above. The deliverability of the wire over time is usually stable. However, when welding is in various places and the conduit tube is bent and the welding wire is fed to the welded portion, as in the case of shipbuilding, the friction coefficient of oil is large, which may make feeding impossible. . On the other hand, the feedability-improving oil containing animal oil or vegetable oil as the main component has a small coefficient of friction and thus has a good feedability, but depending on the type of oil, the oil changes with time, and as a result, it gradually increases with the passage of time. And there are things that feedability becomes worse. It is considered that this is due to the oxidation of oil, etc., but the definite cause is unknown.

In view of the above circumstances, it is an object of the present invention to provide a welding wire which has a small friction coefficient and a small change with time and which is coated on the surface thereof and has a good feedability.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors conducted an experiment for examining the feedability by using a welding wire coated with two kinds of vegetable oils having different iodine values on the surface. It was As a result of this experiment, it was found that as the welding wire coated with vegetable oil having a high iodine value on the surface thereof deteriorates in lubricity (slip) on the surface with the passage of time, the feedability deteriorates with time. Oil with a high iodine value may dry (oxidize) and solidify over time, and this solid matter may be stripped off with welding tips, and the stripped off solid matter may become an obstacle and impair feedability. It was discovered and the present invention was made.

Specifically, the welding wire of the present invention for achieving the above object has an iodine value within a range of 300 ppm or more and 600 ppm or less with an iodine value when the weight of the welding wire is 1. Is less than 100 and the surface is coated with animal oil and / or vegetable oil.

[0007]

The welding wire of the present invention is smoothly and continuously fed because the amount of oil in the range of 300 ppm or more and 600 ppm or less is applied to the surface when the weight of the welding wire is 1. It has good feedability. Further, since this oil is animal oil and / or vegetable oil, the coefficient of friction is small, and even if the conduit tube is bent, the oil cannot be delivered. Furthermore, since this oil has an iodine value of less than 100, it does not change with time and its feedability with time is stable.
As described above, the welding wire of the present invention has good feedability because the surface thereof is coated with oil having a small friction coefficient and a small change with time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the welding wire of the present invention will be described below with reference to the drawings. FIG. 1 shows a wire feeding test apparatus used for investigating the feedability of a welding wire. Here, the feedability was examined using a gas metal arc welding wire having a diameter of 1.2 mm (hereinafter referred to as a wire).

The wire feeding test apparatus 10 has a wire feeding device 20 for feeding a wire, a conduit tube 30 through which the wire passes, and a welding for guiding the wire to a welding portion, like a normal welding machine. A torch 40 is provided, and a welding tip 42 is attached to the tip of the welding torch 40. The conduit tube 30 has a diameter of 300 m
A double-wound portion 32 is formed, which is double-wound by m, so that the feedability is rigorously tested. Also,
The wire feeder 20 includes a spool 22 around which the wire is wound, a wire feeding roll 24 that feeds the wire while sandwiching the wire from the spool 22, and a wire feeding motor (not shown) that drives the wire feeding roll 24. And a digital memory recorder that records the load current of the wire feed motor.

FIG. 2 shows an example of the load current of the wire feeding motor recorded in the digital memory recorder of the wire feeding test apparatus 10. FIG. 2A shows an example using a wire having a good feedability, and FIG. 2B shows an example using a wire having a poor feedability. The load current and the horizontal axis show the feeding time. As shown in FIG. 2, a wire having a good feeding property has a low load current of the wire feeding motor and is stable over time.

FIG. 3 shows the results of examining the feedability of the wire by changing the type of oil applied to the wire surface. The vertical axis represents the standard deviation of the load current (Amp) of the wire feeding motor, and the horizontal axis represents the average current of the load current of the wire feeding motor. In addition, △ in the figure indicates the feedability of a wire coated with animal oil or vegetable oil having an iodine value of less than 100, and ● in the figure represents animal oil or vegetable oil having an iodine value of 100 or more coated on the surface. The feedability of the wire is shown, and the symbol ⋄ in the figure shows the feedability of the wire whose surface is coated with spindle oil (mineral oil), and the coating amount of any oil is 0.3 g / 10 kg wire. This oil coating amount is expressed by using the water conversion value of the Karl Fischer method. Further, the average current of the load current (Amp) of the wire feed motor represents an average feedability level, and the standard deviation represents the degree of variation in feedability and the arc stability thereby.

As shown in FIG. 3, in the case of a wire whose surface is coated with animal oil or vegetable oil having an iodine value of less than 100, the average current and standard deviation of the load current of the wire feeding motor are low, and the feeding performance is good. I know there is. Further, in the case of a wire whose surface is coated with spindle oil (mineral oil), the standard deviation of the load current of the wire feeding motor is low, but the average current is high. Therefore, when the conduit tube bends, wire feeding becomes impossible. Further, in the case of a wire whose surface is coated with animal oil or vegetable oil having an iodine value of 100 or more, the average current and standard deviation of the load current of the wire feed motor are high, and the wire feedability is the worst among them.

In FIG. 4, the iodine value was changed to 100 by changing the amount of oil applied.
The results of examining the feedability of a wire whose surface is coated with animal oil or vegetable oil of less than 50% are shown. The vertical axis shows the standard deviation of the load current (Amp) of the wire feeding motor, and the horizontal axis shows the weight of the wire as 1
Indicates the amount of oil applied. In order to obtain good wire feedability, the standard deviation of the load current of the wire feed motor must be 0.038 Amp or less, as shown in the figure.
The amount of oil applied is 300 ppm or more. Also, the amount of oil applied is 90
If it is 0 ppm or more, welding defects such as pits will occur, so the upper limit of the amount of oil applied is set to 600 ppm, and as a result, the amount of oil applied is 3
It is in the range of 00 ppm or more and 600 ppm or less.

Next, the results of feedability test conducted using a wire having a diameter of 1.2 mm are shown in the table below together with comparative examples. This wire is electrostatically oiled under the following conditions when wound on the spool 22 (see FIG. 1). Refined coconut oil was used as the animal and vegetable oil. Electrostatic mineral oil conditions Number of nozzles: 6 Current: 0.1 ± 0.05 Amp Liquid temperature: 40 ± 5 ° C. Voltage: 13 ± 1 kv Liquid pressure: 10 ± 1 kg / cm ^{2 In} addition, a wire is placed between the cotton cloths where oil has penetrated. The same result was obtained by applying a cotton cloth coating oil that was passed through.

[0015]

[Table 1] ──────────────────────────────────── Evaluation index Conventional results (comparative example) Results of the Invention (Example) Iodine value of animal and vegetable oil 130 95 Animal oil coating amount 400ppm 400ppm Feed motor current value 2.7Amp 1.8Amp Feed motor load current 0.045Amp 0.028Amp standard deviation ─── ───────────────────────────────── As shown in Table 1, the wires of Examples are the wires of Comparative Examples. Good feedability was obtained as compared with.

[0016]

As described above, since the welding wire of the present invention is coated with animal oil and / or vegetable oil having a predetermined amount of oil and iodine value on the surface thereof, it is possible to carry out good welding with little change with time. Have a salary.

[Brief description of drawings]

FIG. 1 is a schematic view showing an apparatus used for examining the feeding property of a welding wire.

FIG. 2 is a graph showing a result of measuring a load current of a wire feeding motor by using a digital memory recorder of the wire feeding test device.

FIG. 3 is a graph showing the results of examining the feedability by changing the type of oil applied to the wire surface.

FIG. 4 is a graph showing the results of examining the feedability of a wire whose surface is coated with animal oil or vegetable oil having an iodine value of less than 100 by changing the amount of oil applied.

[Explanation of symbols]

 10 Wire Feed Test Device 20 Wire Feeder 22 Spool 24 Wire Feed Roll 30 Conduit Tube 40 Welding Torch

Claims (1)

[Claims] 1. An animal oil and / or vegetable oil having an iodine value of less than 100 and having an iodine value of less than 100 when the weight of the welding wire is 1 is in the range of 300 ppm or more and 600 ppm or less. Characteristic welding wire.