JPS59150695A - Composite wire for arc welding - Google Patents

Abstract

PURPOSE:To increase the deposition speed of a wire and to decrease the loss of spatter in the stage of welding by increasing the content of oxygen in the steel of a wire sheath to be packed therein with a flux thereby decreasing the content of carbon. CONSTITUTION:A steel sheath contg. 0.01-0.08wt% oxygen and <=0.05wt% carbon is used in a composite wire formed by packing a flux in the wire sheath. The increase in the content of the oxygen in the wire sheath contributes to an increase in the melting speed of the wire and the decrease in the content of carbon contributes to a decrease in the generation of spatter. The purpose is achieved by regulating the contents of both in the above-mentioned way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite wire for arc welding that can increase the melting rate of the wire and reduce spatter loss during welding in order to improve welding efficiency.

Composite wire for arc welding has characteristics that depend on the type of flux it contains, but in general, whether with or without shielding gas, the bare arc is more stable compared to solid wire, there is less spatter, and welding workability is excellent. . Furthermore, since slag with appropriate viscosity and melting point is produced and this encapsulates the molten metal, it has many advantages such as excellent bead appearance. For this reason, its usage has been rapidly increasing in recent years. In addition, in terms of welding efficiency, when comparing wires of the same diameter, the current density of a composite wire containing flux is higher than that of a solid wire, so the welding speed tends to be higher, and the amount used is increasing. This is one of the reasons why. However, there is a strong desire in industry to further improve the efficiency of the welding process.

In response to such demands from the industry, the present inventors conducted detailed studies on flux formulation, flux filling rate, quality of the outer metal, etc. in order to develop a composite wire with a high welding speed. The welding speed of composite wires can be improved by reducing the amount of arc stabilizer in the flux and increasing the flux filling rate, but it is also known that the welding speed of composite wires can be further improved by increasing the amount of oxygen and decreasing the amount of carbon in the wire sheath. The present invention was completed by obtaining the following.

That is, the present invention provides a composite wire in which the wire sheath is filled with flux, in which the amount of oxygen is 0. O], 00~o, o
This is a bonding wire for arc bath welding characterized by using a steel outer skin having a carbon content of 0.005% or less (weight% or less).

The composite wire according to the present invention will be explained in detail below.

In the present invention, the amount of oxygen in the wire sheath is 0.0100 to 0.
, osoo% because as the amount of oxygen in the outer metal increases, the surface tension of the metal melted at the tip of the wire decreases.
This is due to the knowledge that droplets detach faster. Speeding up the separation of the droplets shortens the time they stay at the tip of the wire, which suppresses the temperature rise of the droplets due to sidual heat and arc radiant heat, and as a result improves the thermal efficiency of the wire melting phenomenon. For this reason, when compared under the same heat generation during welding, that is, under the same current and voltage conditions, speeding up the separation of the droplets increases the melting rate of the wire. This fact is clear from the experimental results shown in FIG. In other words, the amount of oxygen is 0.
．． TlO230% on steel skin in the range of 0030-01%
, 5in25%, At2034%, Fe-81,
(45%Si)15q6. Fe-Mn (75%Mn
) The remaining 25% was a composite wire of 1 and 2 φ containing 15 layers of flux made from iron powder.
, distance between chip base materials 20 mm, CO2 flow rate 20! /
The wire melting rate per minute was determined in downward welding under conditions of 1 minute.

As is clear from the experimental results shown in Figure 1, when the amount of oxygen in the wire jacket is small, the melting rate of the wire is about 95 minutes, but when the amount of oxygen approaches 0.005'O%, the melting rate starts to improve. 0
At 1q6 or more, a high welding rate can be obtained with almost no change. Therefore, the amount of oxygen in the wire sheath used in the composite wire is reduced to 0.
．． By setting it to 0.050% or more, it becomes possible to increase the melting rate of the wire.

However, when the amount of oxygen exceeds 0%, the viscosity of the molten metal decreases too much, and even in downward position welding, the molten metal tends to flow, and poor fusion tends to occur. It has also been found that in order to ensure particularly good workability in posture welding such as vertical welding, it is desirable to set the upper limit of the oxygen amount to 0.0400%.

Furthermore, in the wire of the present invention, the carbon b'f of the wire sheath is 0.0.
The thickness is set at 5 or less in order to reduce spatter loss during welding. That is, as mentioned above, the wire of the present invention uses a mild steel sheath metal with a high oxygen content in order to increase the melting rate of the wire, but the wire sheath with a high oxygen content has a tendency to generate spatter due to the amount of carbon in the wire sheath. It became clear that it would be done. The same flux used in the experiment shown in Figure 1 was applied to a steel jacket in which the oxygen content of the wire jacket was 0.0356% and the carbon content of the wire jacket was in the range of 0.01 to 0.10%, at 15% as in Figure 1. The amount of spatter generated was investigated. As a result, as shown in FIG. 2, it was found that the smaller the amount of carbon, the more the spatter was reduced.

In particular, when the carbon content is 0.05% or less, the occurrence of s/4' ivy is extremely reduced. This phenomenon is due to the fact that when the wire sheath contains a lot of oxygen and carbon, a C0-)Co reaction occurs violently during welding.
Although the occurrence of spatter is significant, by regulating the amount of carbon, it is possible to suppress the C+O→CO reaction and reduce the loss due to smudges. High oxygen like this.

Sputter loss increases in a composite wire using a wire sheath with a high carbon content because the wire sheath contains 81%. This is also due to the lack of deoxidizing elements such as Mn.

If a large amount of 31 + Mn is added to the wire sheath, Sl0
2→810, Mn + 02->MnO2 reaction occurs selectively, (5) C10-)Co reaction is suppressed, but 81. Mn'i
Adding a large amount impairs the formability and drawability of the wire, so in reality, it is common to keep St to as low as possible and Mn to less than 1 modulus. Therefore, in order to increase the wire welding speed and reduce sputter loss when using a wire sheath made of a low S' r Mn type in consideration of the formability and drawability of the wire, it is necessary to improve the wire sheath as in the present invention. It is particularly effective to set the oxygen content to 0.0050 to 0.00 and the osoo% carbon content to 0.05% or less.

The amount of carbon in the wire sheath is a factor that increases the amount of snow ivy when the amount of oxygen is high, as explained above, but the amount of carbon in the flux has almost no effect depending on the method of addition. It turns out that there is something.゛For example, Ca
When carbonates such as CO3 and LiC0 are added, CO2 is rapidly generated due to arc heat, which causes an increase in spatter. However, it has been found that when added to so-called deoxidizing metals or alloys, such as iron-manganese alloys, which have a strong affinity for carbon and oxygen, it does not lead to an increase in the number of black ivy. This is thought to be due to the fact that the rapid C+O→CO reaction is inhibited by the deoxidizing element. Therefore, if a low carbon wire sheath is used to avoid spatter loss, but the carbon content of the weld metal is insufficient and strength cannot be ensured, silicon, manganese, etc. may be added to ensure strength. It is possible. However, this method has the disadvantage of high cost, so adding carbon to the deoxidizing metal to yield the weld metal is the most inexpensive and practical solution.

Note that most of the graphite applied to the wire surface for the purpose of improving wire feedability during welding or the carbon in the lubricating oil component is scattered by Joule heat or arc heat caused by the current flowing through the wire, so it becomes C+o-+CO. The reaction hardly causes an increase in spatter. Therefore, there are no particular restrictions on the various surface treatments that can be applied to improve wire feedability and rust resistance.

The type of flux included in the wire sheath is not particularly limited, and may be a composite wire for gas shield welding whose main component is TlO2, CaF2. Composite wires for gas shield or self-shield welding that are mainly composed of metal fluorides such as BaF2, and composite wires for gas shield welding that are mainly composed of metal powder with reduced slag forming agents, etc. are manufactured using the wire sheath of the present invention. can do. The weight percentage of the flux contained in the wire sheath is preferably about 5 to 45%; if it is less than 5%, the amounts of the slag forming agent, alloying agent, and deoxidizing agent are insufficient, and sound welding cannot be performed.

On the other hand, if more than 45 inches of flux is filled, the wire outer sheath becomes too thin, making it easy to break and deteriorating the wire feedability. Therefore, the weight ratio of the flux to the wire is preferably 5 to 45%. Furthermore, there is no particular restriction on the cross-sectional shape of the wire; the effect of the present invention can be achieved with any cross-section shown in FIG. This has the advantage that the flux absorbs less moisture and the wire has no directionality, which reduces the frequency of trouble during welding.In addition, this cross section allows various treatments to be applied freely to the wire surface, so it is easy to conduct electricity. It is also possible to perform copper plating for the purpose of improving properties and rust resistance.

The wire diameter can be freely selected from a small diameter of about 1.2 mynφ to a large diameter of about 41 nmφ depending on the application.

Next, the present invention will be explained in more detail with reference to Examples.

Example Table 1 shows the configuration and test results of the prototype wire. In the same table, wires 1 to 3 are comparative examples, and wires 4 to 8 are examples of the wire according to the present invention.

Both wires have the cross-sectional shape shown in Figure 3 (a) with no openings in the wire sheath, and the surface is copper plated.
, finished to 2 mmφ.

The bath welding efficiency is a welding current of 300A using a downward automatic welding machine.
, arc voltage 30V, welding speed 30 cm/min.

Chip-base metal distance 20mm, CO2 flow rate 20mm! /min.

Welding was carried out under the condition of an arc time of 1 minute, and the melting speed and welding speed of the wire were actually measured. The degree of spatter loss was determined by observation during welding and the magnitude of welding efficiency.

(9) Since the wires of JiS 1 and 2 are low in oxygen and high in carbon, welding workability is good, but the welding speed is slow. The wire of No. 3, in which the oxygen concentration was increased to 0.0860%, exceeding the J limit of the present invention, had a melting rate of 1151! Although the process speed is as fast as 1/min, the bath-molten metal flows easily and has a large amount of carbon, so there is a lot of sputtering loss.

(10) On the other hand, the wires of A4 to A8 according to the present invention have a fast melting rate and a small i+vine loss. It was also confirmed that welding workability was good.

As clarified by the above examples, the composite wire of the present invention manufactured using a high-oxygen, low-carbon wire sheath has a fast wire melting rate, high welding efficiency, and excellent welding workability. Therefore, it is expected that it will greatly contribute to improving welding efficiency in the future.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the amount of oxygen in the wire sheath and the melting rate, Figure 2 is a diagram showing the relationship between the amount of carbon in the wire sheath and the amount of spatter generated, and Figure 3 is a diagram showing an example of the cross-sectional shape of the wire. be. Patent Applicant: Nippon Steel Corporation 480- (Buddha) 7 TO 4 Shishi 9 Δ Otsu Sa/) I Ward Patent Office Commissioner Kazuo Wakasugi 1. Display of the case 1982 Patent Application No. 022919 2 Name of the invention Composite wire for arc welding 3 Person making the amendment Relationship to the case Patent applicant representative Takeshi 1) Yutaka 4, agent 〒100 6, amendment Claims column of the subject specification and detailed description of the invention 1)
The scope of claims is amended as shown in the attached sheet. 2) Lines 2 to 1 from the bottom of page 2 of the specification “Oxygen amount O, O], 0
0 to o, osoo%” to “Oxygen amount is 0.01 to 0.08
%”. 3) Page 3, lines 5-6 “Oxygen amount 0.0100-0.08
00%" is corrected to "Oxygen amount 0.01 to 0.08%." 4) 4 lines from the bottom of page 3 “The amount of oxygen is 0.0030 to 0.1
%" is corrected to "oxygen amount 0.003-0.1%". 5) Same page 4 lines 6 and 9 r0.0050%” ro, 0
Correct each to 05%j. 6) Same page 4 line 11 ro, osoo%” ro, os%”
Correct to. 7) Same page 4 line 15 r0.0400%"ro, 04%"
Correct to. 8) Same page 6 line 8 “Oxygen amount 0.0050 to 0.0800
% carbon content" is corrected to "oxygen content 0.01 to 0.08%, carbon content". Claims: A composite wire for arc welding, characterized in that the wire sheath is filled with 7 lux and has a steel sheath having a composite wax content of 0.05% or less and a carbon content of 0.05% or less. Procedural amendment (spontaneous) May 2, 1980 Mr. Kazuo Wakasugi, Commissioner of the Patent Office, Indication of the case 1982 Patent Application No. 022919 2, Name of the invention Composite wire for arc welding 3, Person making the amendment Relationship to the case Patent applicant 2-6-3 Otemachi, Chiyoda-ku, Tokyo (665) Nippon Steel Corporation Representative Takeshi 1) Yutaka 4, Agent 2-4-1 Marunouchi, Chiyoda-ku, Tokyo 100 No. 6, Detailed description of the invention and drawings in the specification subject to amendment (1) Description 5
Page 5 line [when oxygen amount is 0.0356%] is changed to "Oxygen amount is 0.0356%".
Corrected to ``at around 03%.'' (2) The bottom line of page 5 “Mn10-+Mn0z J”
Correct n +0→MnOJ. (3) On page 8, in the 5th line from the bottom, ``Low moisture absorption'' is corrected to ``No moisture absorption.'' (4) Correct Figure 1 as shown in the attached sheet. (2) Figure 1 θ001 θ, OO5θ1θl
θ, OE θt O, E amount of oxygen in the wire (%)

Claims (1)

[Claims] Arc welding characterized in that, in a composite wire formed by filling the wire sheath with flux, a steel sheath having an oxygen content of 0.0100 to 0.0800% by weight and a carbon content of 0.05% or less is used entirely. composite wire.