JPS63260695A - Production of flux cored wire for arc welding - Google Patents

Abstract

PURPOSE:To improve welding efficiency and welding quality by adding TiO2 combining beforehand Bi or Bi compound at the specific wt.%, at the prescribed % in a flux and further filling the flux at the prescribed % to the total wire wt. CONSTITUTION:Metallic Bi or Bi compound is beforehand combined at 0.2-3.0 wt.% to the total wt.% of TiO2 as metallic Bi. Further this TiO2 is added at 25-55% ratio of the total wt. of the flux and the remaining composition in the flux is formed by slag generating agent, arc stabilizer and deoxidizer except TiO2. Next, this flux is filled in an outer shell of the metal at 9-25% ratio of the total wt. of the wire, to form a composite wire. As the Bi or the Bi compound is beforehand combined with TiO2, the segregation of Bi is eliminated and the variance of detachability of the slag is eliminated. By this method, the welding efficiency and the welded quality are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite wire for arc welding, and in particular to a method for manufacturing a composite wire for 7-way welding (hereinafter referred to as composite wire) with excellent slag removability. .

(Prior art) Does a composite wire containing 7 lux of TiOx as a main component have a stable arc and be smooth? Because it has the advantages of less friction and an excellent bead appearance, it is widely used in structures made mainly of mild steel and 50 kg class high tensile strength steel.

However, the slag of a composite wire containing 7 lux of TiOx as its main component is hard and easily sticks to the bead, making it difficult to remove the slag, especially within the groove, which has been an obstacle to improving welding efficiency. To solve this problem, T i Ox system filling 7
A method of adding a small amount of a low melting point sulfide or oxide with a melting point of 500 to 1300°C to FAX to improve the peelability of slag (Japanese Unexamined Patent Application Publication No. 1987-190798), or filling with Bi 7-77 or outer shell. A method for improving the removability of slag by adding a small amount to the metal sheath (Special IM 1983-
13495) etc. are known.

(Problem to be solved by the invention) In this way, these low melting point sulfides, oxides or Bi
Although the slag removability is improved by adding such substances to the filled black, the addition amount is very small, which tends to cause the problem of segregation, which causes variations among composite wire products.
Made! In addition, if B is included in the outer metal sheath, 1. When manufacturing a composite wire with a small diameter such as O+*mφ, wire breakage is likely to occur, resulting in a problem of deterioration of productivity.

In view of the above-mentioned problems, the present invention provides a method for manufacturing a composite wire that eliminates the variation in slag removability between products of T i OZ composite wire and allows highly efficient all-position welding.

(Means for Solving the Problems) In the method for manufacturing a composite wire for arc welding according to the present invention, a Bi compound or metal bismuth is added in advance in an amount of 0.2 to 3.0% in terms of Bi based on the total weight of TiOZ. Combine that T
iOt is added in an amount of 25 to 55% based on the total weight of 7lux, and 7fux, which includes a slag forming agent other than TiOz, an arc stabilizer, and a deoxidizing agent, is added in an amount of 9 to 25% by weight based on the total weight of the wire. It is characterized by

(Function) Below, the reason why the method for manufacturing a composite wire for welding according to the present invention is configured as described above will be explained in detail.

The present inventors have found that the low melting, 5'7: V2O5, PbO%r'bs of the compound shown in JP-A No. 57-190798
.

AbO, AbS%SnO, SnS%GeO, GeS, F
eS.

B iS , B i20 , and JP-A-58-
Using 13 types of metal bismuth shown in Japanese Patent No. 13495, each was added in an amount of 0.2% by weight based on the total weight of 7 lacs based on the ingredients shown in Table 1, and the lacquer filling rate was 1.
Thirteen types of composite wires with a cross-sectional shape of 1.21φ and a cross-sectional shape shown in the m1 diagram (b) were manufactured using 2% m1. Using this composite wire, a slag removability test was conducted when welding in a downward position under the following welding conditions 1 (failed).

Welding conditions 1 Welding current 270A Voltage 30V Welding speed 30cm/in Distance between wire tip and base metal 25I CO, flow rate 20l/+ain Steel plate 5M-41B45°V 12
5 tX 100 w
The total length of the slag was evaluated quantitatively.

As a result, as shown in the tjS2 diagram, metal bismuth, Bi
zo 2, excluding BiS (for composite wires with low melting point compounds added, even if a load of 1.5 - 5 is dropped onto the weld 20 times, the slag will be 3
The peeling was about 0 to 90%, but metal vinyl XvX, B
LOs, B i S compound 4111 wo0, 2 tf
It was found that the wire to which J amount % was added completely peeled off the slag after 6 to 10 impacts.

Therefore, next, we selected Bizo 3, added 0.2 mfi% to the total JllHft to the basic 7 hooks shown in Table 1, and made a 1. A 1-ton prototype of a composite wire formed to 2.0 mm diameter was manufactured at a factory, and the variation in slag releasability between lofts was investigated. In other words, 1 ton of factory prototype is JIS-Z33
A 20 kg spool shown in Fig. 12 was randomly selected from these prototypes, and a slag releasability test was conducted under the above-mentioned welding condition 1.

The method for evaluating the variation in slag peeling was the same as described above.

The experimental results are shown in FIG. 3, and it was found that there was a large variation in slag peeling between each spool.

The reason for this is thought to be that the blended amount of Bizo 3, which is added in a small amount to improve slag peeling, is as low as 0.2%, which causes segregation of Bizo 3 and increases the variation between products. It will be done.

Therefore, as a result of considering a means to eliminate the variation in slag removability between lofts, we found that T io! The following experiment revealed that it is sufficient to first fix the Bi compound or metal bismuth with a binder such as fuss.

That is, TiO, which is the main component, is bonded with potassium silicate in advance to bind 0.5 weight 1% of B i=03 to the total weight of TiO, and this Ti12 is used to bond the second
7 shown in the table? A 1-ton composite wire of 1.2 Iφ having the cross-sectional shape shown in FIG. 1(b) was manufactured as a prototype at a factory with a filling rate of 12% as described above, and the buffiness of the slag removability was investigated. The investigation results are shown in FIG. 4, and it was found that there was no variation among the spools, and good slag removability was exhibited. In other words, partial granulation of the main components TiO2 and Bit's eliminates segregation and eliminates variations between products! I made it clear.

In the present invention, Bi compound or metal bismuth is added in advance to T.
r Oz 0.2 to 3.0 in B1 conversion to total ffl amount
% combine. This is because if it is less than 0.2%, sufficient slag releasability cannot be obtained, and if it exceeds 3.0%, problems such as an increase in the amount of welding fume and a decrease in impact toughness occur. Furthermore, in the present invention, sit! 0.2-3.0 in AB
% bound T i O2 to 7 lux total it
Add 5-55%. If it is less than 25%, arc stabilizing effect and stable slag@femality cannot be obtained, and if it exceeds 55%, the melting point of the slag will become high, causing problems such as slag entrainment and reduction of impact toughness, especially in downward welding. occurs.

In addition, in the present invention, a filling 7 other than T i O2 combined with a Bi compound or metal bismuth is used. Additives for γx include 5in2, ZrO2, and ALO as slag forming agents.
3. Fe2O3, Na and O as arc stabilizers.

K , 0% K 2T io , tesi as a deoxidizer,
Mn, A1, Mgs T i , Ni, M as alloying agent
o, B, Cr, iron powder, etc. are appropriately blended.

The entire 7 lux is 1fL'f of wire! 9-2 for L
Fill with 5%. If it is less than 9%, sufficient effect cannot be expected due to insufficient filling 7 rafux, and if it exceeds 25%, it will be 1, OIφ
When manufacturing small diameter composite wires such as
A problem arises in that productivity deteriorates. Furthermore, the cross-sectional shape of the composite wire may be one that does not have a seam on the circumference of the outer skin as shown in Figure PI3 (, ).

(Example) The effects of the present invention will be explained in more detail with reference to Examples.

Composite wires Nos. 1 to 14 with a filling rate of 12% and a cross-sectional shape of 1.21φ as shown in FIG. 1(b) were made by using 7 lux having the component m shown in Table tjS3.

Welding conditions 2 below using these prototype wires in a downward position
The slag peeling rate during one impact when welding was investigated. In addition, welding was carried out under the following welding conditions 3 according to JIS Z 3313, an impact test piece was taken, and the impact toughness at 0°C was investigated.
In accordance with 930, fumes generated during welding under the following welding conditions 4 are fully fitted with a high volume air sampler.
Collect 4+ fl and calculate the amount of fume generated per unit time (-g/
(request) was determined and determined based on the average value obtained when the experiment was repeated three times. The measurement results are shown in Table 4.

Welding conditions 2 Welding current 270A Arc voltage 30V Welding speed 30 am/sin Distance between wire tip and base metal 25mm C0, flow i1 20 1/sin Steel plate 5M-41B45°V 1125
LX 100wX 3001 Welding conditions 3 Welding current 270A Arc voltage 30V Welding speed 30cm/min Distance between wire tip and base metal 25+am CO, ail 20 1/ +*i
n steel plate 5M-41B welding conditions 4 Welding current 270A Arc voltage 30V Welding speed 30e theory/distance between Tsuru in wire tip and base metal 20 wheel theory CO2 flow rate 20 1/ll1n Steel plate 5M-41B Shown in Table 4 In the test results, wire No. 1.2 is a conventional example. Comparative example wire No. 3.4 added 3.0% in terms of Bi, but no particular effect could be expected; on the contrary, it increased the amount of welding heat, and the absorbed energy at 0°C was low. Comparative example wire N has large variations.
Since o, 5 was less than 0.2% in terms of Bi, sufficient slag releasability could not be obtained. Comparative example wire No.
In No. 6, 0.3% TiOs combined in terms of Bi was added in an amount exceeding 55% of the total weight of No. 7 Lacs, so the melting point of the slag became high, and slag entrainment occurred especially during downward welding, resulting in a lower temperature at 0°C. Absorbed energy is also low.

In addition, the wire of Comparative Example No. 7 has a TiOs content of less than 25%, resulting in poor arc stability and a large amount of sputtering, making it impossible to expect stable slag peeling properties.

On the other hand, No. 2, which is a wire made by the method of the present invention.

8 to 14 can remove 100% of the slag with a single impact, have good arc stability, and have a welding volume of 6.
It can be seen that the absorbed energy at 0° C. is extremely low, less than 0.00 B/win, and is stable and high.

(Effects of the Invention) As explained above, according to the present invention, variations in slag releasability among products of TiO□-based composite wire can be largely eliminated, and welding efficiency and welding quality are improved.

[Brief explanation of the drawing]

The tirJi diagram is a cross-sectional view showing the shape of a composite wire, Figure 2 is a diagram showing the relationship between the number of drops and the slag peeling rate when using a low melting point compound and metal bismuth, Figure 3 and f54 are for a 20kg spool It is a figure which shows the slag peeling rate when 20 coils are used. 1...Flux, 2...Metal sheath.

Claims (1)

[Claims] (1) Bi compound or metal bismuth is added to TiO_2 in advance.
Bind 0.2 to 3.0% in terms of Bi based on the total weight,
The TiO_2 is 25 to 55% of the total weight of the flux.
A method for producing a composite wire for arc welding, characterized in that flux containing a slag forming agent other than TiO_2, an arc stabilizer, and a deoxidizing agent is filled in an amount of 9 to 25% by weight based on the total weight of the wire.