JPH0976089A - Steel wire for arc welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out the welding in which no clogging in a conduit cable or deposition of the lubricant composition on a feeding roll is made even in the case of the welding under the high current condition, no slip of the wire is made on a feeding roll even in the severe bending condition, the friction resistance is small, the feedability is excellent, and the arc is stable even for a long time. SOLUTION: The ether extraction is 0.1-1.2g per 10kg of wire when the adhered substance to the surface of the wire for the arc welding is ultrasonic- cleaned in ether, while the toluene extraction from the ether-cleaned wire which is further ultrasonic-cleaned in warm toluene at 60-70 deg.C is 0.01-1.2g per 10kg of wire. The total weight of the solid lubricant having the composition consisting of one or two or more kinds of MoS2 , WS2 , PTFE, C, graphite fluoride, and metallic soap in the filtered residue which is obtained by filtering the ether and toluene extraction by the filter paper (membrane filter) having holes having the diameter of 3μm, is 0.01-0.4g per 10kg of wire, and the wire surface roughness Ra in the longitudinal direction of the wire is 0.05-0.5μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a steel wire for arc welding, and more particularly, it is excellent in feedability during welding, has stable arc, and can maintain good work for a long time. It relates to a steel wire for use.

[0002]

2. Description of the Related Art Steel wires for arc welding tend to be used more and more with the progress of automation and higher efficiency of welding, but recently, from the viewpoint of efficiency, high current of high current is used regardless of automatic or semi-automatic welding. Welding conditions are being adopted. As a result, the wire feeding speed inevitably increases. In addition, depending on the target structure, welding is often performed in narrow spaces, and from the viewpoint of ease of use at those locations, the conduit cable from the feed roll of the wire feeder of the welding machine to the welding torch. Since it is easy to use even when bent, it tends to be soft and long.

As described above, when the welding wire is fed at a high speed and is used in a long and easily bendable conduit cable, friction occurs when the wire passes through the conduit tube in the conduit cable at the time of feeding the wire. There is a problem that the resistance becomes large, the wire feeding at the time of welding is hindered, the arc becomes unstable, and welding cannot be performed. Therefore, the steel wire for arc welding has been
Various measures have been taken to improve the wire feedability, but none are sufficient, and welding workers are often forced to interrupt welding under severe conditions and replace worn conduit tubes. It is the actual situation that they are having difficulty responding to this.

With respect to the problem of the feedability of these welding wires, conventionally, for example, JP-A-55-40068 discloses an ester composed of a higher fatty acid and a higher monohydric alcohol, the ester and MoS ₂ , graphite, etc. Steel wire for arc welding mixed with and coated with aluminum, or JP-A-58-184
Japanese Patent Laid-Open No. 095 proposes a steel wire for arc welding in which a mixture of solid lubricants such as graphite, molybdenum disulfide and glass powder is applied to the surface of a steel wire.

However, even with these steel wires for arc welding, under the severe conditions where the above-mentioned soft and long conduit cable is used and welding is performed under high current conditions, the wire is not used in the feeding roll section. Slips or the frictional resistance inside the conduit tube is large, and the inside of the conduit tube becomes hot due to frictional heat and heat generated by the welding cable that wraps the conduit liner, causing the lubricant on the wire surface to partially melt and aggregate, causing the wire surface As a result, it cannot be uniformly coated and the feedability becomes unsatisfactory. In addition, the melted lubricant can remove other wire deposits such as copper and iron from the conduit tube and
There is a problem that it is deposited in the inner tube and the tip to narrow the wire passage and increase the feeding resistance and the conduction resistance of the tip, which hinders stable maintenance of the arc.

[0006]

Therefore, the present invention uses a soft and long conduit cable, and even when it is welded under a high current condition, there is a clogging in the conduit cable and a copper wire on the feed roll. There is no accumulation of lubricant components such as iron, there is no wire slip on the feed roll even under severe bending conditions, and there is little friction resistance, good feedability, and stable arc welding for a long time. It is an object of the present invention to provide a steel wire for arc welding which can be manufactured.

[0007]

Means for Solving the Problems As a means for solving the above-mentioned problems, the present invention is to ultrasonically clean a steel wire for arc welding in ether and extract the adhered amount of the extracted surface per 10 kg of the wire. 0.1 to 1.2 g, the wire after ether cleaning is further ultrasonically cleaned in warm toluene at 60 to 70 ° C.
0.01-1.2 g per kg, ether and toluene extract the extract filter paper with a pore size of 3 μm (membrane filter)
MoS ₂ , WS ₂ , PTFE, C,
The total amount of one or more solid lubricants of fluorinated graphite and metal soap is 0.01 to 0.4 g per 10 kg of wire, and the wire surface roughness Ra in the wire length direction is 0.05 to 0. The steel wire for arc welding is characterized by having a thickness of 0.5 μm.

[0008]

The present invention will be described in more detail below. The present inventors have taken photographs of the phenomenon of wire feeding and arc during welding for the purpose of maintaining stable welding for a long time even under severe conditions.
From the results of observation using various devices such as high-speed video and waveform analysis, and the analysis results of the wire surface, the lubricant on the wire surface covers the outermost layer with a small amount of liquid lubricant, and the solid or semi-solid lubricant underneath it. It has been found that, by adopting a two-layer structure for firmly adhering, stable welding can be maintained for a long time even under the severe conditions described above.

That is, among the fatty acids, esters of monohydric or dihydric alcohols of fatty acids or one or more of petroleum waxes (hereinafter referred to as waxes) which are mainly extracted with warm toluene, the one having a high melting point is selected. Apply a suitable amount of wax, etc., and finally extract with ether. Apply liquid oils at room temperature to further add MoS ₂ , WS ₂ , PTFE, C, fluorinated into wax etc. By adding one or more of graphite and metal soap, even under severe conditions such as the use of conduit cables and high current conditions, the conduit cables may become clogged and the feed roll may contain copper and iron, etc. Less deposition of agent components, less slippage on the feed roll even under severe bending conditions, and less frictional resistance in the conduit cable. , Wire feedability is very good, it is stable welding arc even long. These effects can be achieved by the coexistence effect of each composition, and the reasons for limiting each composition will be described below.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION First, the present inventors investigated various effects of deposits on the wire surface for the purpose of improving feedability, and various methods for confirming the amount and composition for controlling deposits. investigated. As a result, it has been found that it is best to wash the extract with an appropriate solvent and analyze the extract as a method for analyzing the substance attached on the wire surface in a trace amount with high accuracy and relatively easily. Therefore, the deposit was extracted with an organic solvent, and the relationship between the amount and the feedability and other welding characteristics was studied. However, the phenomenon could not be sufficiently clarified only by the total amount of deposits, and it was necessary to separate and analyze the deposits.As a result of studying various separation methods, the last applied oil was ultrasonicated in ether. It was possible to extract relatively easily by washing,
As a result of examining various methods of extracting wax and the like that are strongly adhered directly to the wire accurately and efficiently,
It was found that heating the toluene to 60 to 70 ° C was the most efficient and stable extraction was possible. Further, if the temperature of toluene is lower than 60 ° C., it takes time to reach the extraction end point, the end point is not clear, and the extraction amount is not stable. On the other hand, at temperatures exceeding 70 ° C, the extraction temperature is limited to 60 to 70 ° C because the evaporation becomes severe and the risk of ignition increases.

The wire surface deposits extracted with hot toluene are mainly high melting point fatty acids, which are deposited in the early stage of the finish wire drawing process in order to improve the wire feedability, and esters of fatty acid monohydric or dihydric alcohols. And one or more petroleum waxes, or a solid lubricant added thereto. The hot toluene extract has the effect of lowering the frictional resistance between the wire and the conduit liner during wire feeding, and in particular, under the more severe conditions such as long welding at high current, solid lubricant with high lubricity is applied to the wire surface. The effect is that even if a long conduit cable is held, it will not run out of lubrication.

However, as shown in FIG. 1, if the amount of hot toluene extraction deposits is less than 0.01 g per 10 kg of wire, lubrication and other solid lubricants cannot be uniformly held on the surface of the wire, so that it cannot be fed inside the conduit cable. The supply resistance is high and it is not possible to weld stably due to wire buckling. In addition, as shown in FIG. 2, when it exceeds 1.2 g,
Due to excessive lubrication, slipping easily occurs on the feed rolls and the feed is not stable, and stable welding cannot be performed. The method of measuring and calculating the slip ratio of the wire will be described in detail in Examples. In addition, since excessive deposits are likely to be deposited on the feed roll, conduit liner and tip, the conduit liner or the like is clogged with welding for a long time and the arc becomes unstable. Therefore, the amount of hot toluene extracted needs to be limited to 0.1 to 1.2 g per 10 kg of wire.

Further, the ether extract is mainly composed of oil which is liquid at room temperature and is applied in the final step of wire production. However, the oil application lowers the feeding resistance as compared with the case where only wax or the like and the solid lubricant are used. It has the effect of more stable feeding under various conditions. That is, as shown in FIG. 3 or 4, when welding is started in a low temperature environment such as winter (average temperature of 5 ° C. or less), the armature current value is generally high and the wire feeding may become unstable. Even in such a case, the application of oil has the effect of reducing the armature current and shortening the time until the arc stabilizes. It also has the effect of imparting luster to the wire surface to improve the appearance and maintain the luster. However, these effects are not observed when the amount is less than 0.1 g per 10 kg of wire, and when the amount is more than 1.2 g, the feeding roll is rather liable to slip and the feeding becomes unstable. Therefore, in the present invention, the amount of coating oil extracted with ether was limited to 0.1 to 1.2 g per 10 kg of wire.

Also, depending on the feeding conditions, ether and 60
The total amount of the residue obtained by filtering the hot toluene extract at ˜70 ° C. with a filter paper (membrane filter) having a pore size of 3 μm is the wire 10.
MoS ₂ to be 0.01 to 0.4 g per kg,
Stable wire feeding under more severe conditions is possible by uniformly mixing and adhering one or more solid lubricants of WS ₂ , PTFE, C, fluorinated graphite and metal soap into wax. Becomes However, if the amount is less than 0.01 g per 10 kg of wire, the effect is not recognized, and if it exceeds 0.4 g, slipping easily occurs in the feed roll portion and the energization of the tip becomes unstable. Further, long-time welding causes arc instability due to clogging in the conduit liner, and cannot be used for a long time. Other than the above, solid lubricant components include talc, sericite, lime, boron nitride, plastics, and various metal oxides, and these can be added as necessary.

Further, according to the present invention, by specifying the average roughness Ra of the wire surface in the length direction, it is possible to secure a stable wire feeding property even under severer cable conditions and to stably apply a lubricant to the wire surface. Can be held at. However, the average roughness Ra of the wire surface is 0.0
If it is less than 5 μm, the lubricant cannot be stably held on the wire surface, and the wire feeding property becomes unstable.
When the average roughness Ra of the wire surface exceeds 0.5 μm, a large amount of lubricant adheres to the wire surface, the wire easily slips on the feed roll part, the feed is not stable, and the arc becomes unstable, resulting in spatter. Also increases. Therefore, in the present invention, the wire surface roughness Ra is limited to 0.05 μm to 0.5 μm.

[0016]

The present invention will be described in more detail with reference to the following examples. First, JISZ with a wire diameter of 1.4 mm, in which the type and amount of the coating oil that becomes the ether extract and the wax that becomes the hot toluene extract on the surface of the steel wire for arc welding are adjusted.
YFW-C50DR seamless flux-cored wire (flux filling rate 14%) specified in 3313 was produced. The test wire was filled with a filling flux at a predetermined filling rate and then drawn to an annealed diameter, followed by electrolytic pickling and plating. Wax or the like or a product obtained by adding a solid lubricant to wax or the like was adhered and washed in the finish wire drawing step of the wire to control the roughness and the amount of adhesion of the base surface. Further, immediately before the aligned winding step, after cleaning, the amount of oil was controlled and applied, and the spool was subjected to a winding test. Average surface roughness of wire R
In accordance with JIS B0601, “a” was measured by a contact-type surface roughness meter, rotated 12.5 mm in the length direction at 90 ° for four times, and the average value was taken.

The wire feedability was investigated by using the device shown in FIG. That is, in order to increase the feeding resistance in the middle of the 6 m conduit cable, the diameter of the loop is set to 150φ to 80
Two rotations were provided for the loop that was gradually changed to φ. The wire is fed from the spool 2 to the conduit cable 1 by the feeding motor 3 and sent to the torch 4. At this time, 10 kg of wire was welded. The welding conditions at that time were current: 350 A, voltage: 32 V, speed: 30 cm / mi.
n, CO ₂ : 25 l / min, and the pressure of the feed roll was kept constant at 25 kg.

The wire feedability was examined by measuring the armature current value of the feed motor 3. Regarding the wire feedability, when the armature current value exceeds 3.5 A, the arc length changes and the arc becomes unstable. The slip of the wire in the wire feeding roll section was examined by measuring the peripheral speed of the feeding roll and the wire speed at the feeding roll outlet side, and calculating the slip ratio by the following formula. If the slip ratio of the wire exceeds 5%, the wire feeding speed becomes slow and rapid, and the arc becomes unstable due to the uneven feeding of the wire, and the spatter increases. In addition,
The peripheral speed of the wire was calculated from the diameter of the feed roll by measuring the rotation of the feed motor with a rotary encoder. Also,
The wire speed on the outlet side was measured by installing a laser Doppler linear velocity meter. Slip rate = (peripheral speed of feed roll) − (wire speed on exit side of feed roll) / (peripheral speed of feed roll) × 100

The results are summarized in Table 1. Table 1
In, test Nos. 1 to 18 are steel wires for arc welding according to the present invention, and test Nos. 19 to 26 are comparative examples. Test Nos. 1 to 18 of the present invention have very satisfactory results because the slip ratio during welding and the armature current value of the feed motor are low and the arc is stable even under conditions where the bending condition of the conduit cable is more severe than 150φ × 2 turns. there were. No in the comparative example
No. 19 is a case where the amount of extracted ether is less than the lower limit of the range of the present invention, the armature current value and the slip ratio are high, and the arc is not stable.

No. 20 is a case where the amount of toluene extracted is less than the lower limit of the range of the present invention, the armature current value and the slip ratio are high, and the arc becomes unstable. No. 21 is within the scope of the present invention for the ether extracted portion and the toluene extracted portion, but when the wire surface roughness Ra is less than the lower limit of the present invention, and the bending motor of the conduit cable is 150φ × 2 turns The wire current is too high to feed the wire.
No. 22 is the case where the ether extraction amount exceeds the upper limit of the present invention, the wire slips on the feed roll, the armature current value is high, the slip ratio is also very high, and the arc is not stable. No. 23 is the case where the amount of toluene extracted exceeds the upper limit of the present invention, the wire slips on the feed roll, the armature current value is high, and the slip ratio is also very high.
The arc is not stable.

In No. 24, the ether extracted portion and the toluene extracted portion are within the scope of the present invention, but when the wire surface roughness Ra is larger than the upper limit of the present invention, the feed motor is used under the bending condition of the conduit cable of 150φ × 2 turns. Armature current is high and the wire is not fed. No. 25 is the case where the residual amount when the ether and toluene extracted components are filtered with a filter paper having a pore size of 3 μm is less than the lower limit of the present invention, and the bending motor condition of the conduit cable is 150φ × 2 turns, the armature current of the feed motor is high, Wire is not fed. No. 26 is a case where the residual amount when the ether and toluene extracted components are filtered with a filter paper having a pore size of 3 μm exceeds the upper limit of the present invention, the wire slips on the feed roll, the armature current value is high, and the slip ratio is also high. Very high and arc is not stable. In these examples, the seamless flux-cored wire having a diameter of 1.4 mm was shown, but similar results were obtained with a smaller diameter and a larger diameter. Similar results were also obtained for flux-cored wires with seams and solid wires plated with copper.

[0022]

[Table 1]

[0023]

As described above, according to the steel wire for arc welding of the present invention, even when a soft and long conduit cable is used and it is welded under a high current condition, No clogging and no buildup of lubricating components on the feed rolls, no slip on the feed rolls even under severe bending conditions, and low frictional resistance for good feedability and stable arc welding even for long periods of time. It has an excellent effect that enables

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a toluene extraction amount and an armature current of a wire feeding motor,

FIG. 2 is a diagram showing a relationship between a toluene extracted amount, an armature current of a wire feeding motor, and a wire slip ratio;

FIG. 3 is a diagram showing the relationship between the welding time and the armature current of the wire feeding motor, the slip ratio of the wire, and the temperature of the conduit cable when oil is not applied immediately before the aligned winding.

FIG. 4 is a diagram showing a relationship between welding time, armature current of a wire feeding motor, wire slip ratio, and temperature of a conduit cable when oil is applied immediately before alignment winding.

FIG. 5 is a diagram showing a welding device used in an example of the present invention.

[Explanation of symbols]

 1 Conduit cable 2 Wire spool 3 Feed motor 4 Welding torch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Hayashi 7-6-1, Higashi Narashino, Narashino-shi, Chiba Nippon Welding Industry Co., Ltd. Narashino factory

Claims (1)

[Claims] 1. An ether extract when ultrasonically cleaning deposits on the surface of a steel wire for arc welding in ether is 0.1 to 1.2 g per 10 kg of the wire, and the wire after the ether cleaning is further 60 to 70. Toluene extract ultrasonically washed in warm toluene at ℃ 0.01
.About.1.2 g, ether and toluene extracts were filtered through a filter paper (membrane filter) having a pore size of 3 μm, respectively, and MoS ₂ , WS ₂ , PTFE, C, fluorinated graphite in the residue,
The total amount of one or more solid lubricants of metal soap is 0.01 to 0.4 g per 10 kg of wire, and
The wire surface roughness Ra in the wire length direction is 0.05 to 0.
Steel wire for arc welding, characterized by having a thickness of 5 μm.