JPS63199091A - Gas shielded arc welding wire - Google Patents

Abstract

PURPOSE:To improve a bead shape by specifying the contents of Si and Mn in the compsn. of a wire for gas shielded arc welding and incorporating an adequate ratio of O therein. CONSTITUTION:The wire for gas shielded arc welding contains <=0.15% C, 0.05-0.45% Si and 0.45-2.0% Mn. Said wire has the alloy compsn. which contains Mn=0.45+0.75(Si-0.05)% in a 0.45%<=Mn<=0.75% range, contains further 0.005-0.030% O and consists of the balance substantially Fe. The bead shape is thereby improved and the preferable condition of H/W<=0.45 is satisfied.

Description

[Detailed description of the invention]

Five plate power

[Industrial application field]

The present invention relates to improvements in wires for gas shielded arc welding.

[Conventional technology]

CO2, Ar or Ar+CO2 as shielding gas
There are many standards for solid wires for gas-shielded arc welding, depending on the type of steel material to be welded and the welding conditions. In most cases, C: 0.12% or less (0.24% for overlay use)
), S, i: 0.4~1.0%, Mn: 0.9~
2.5% and the remainder is essentially Fe, with some CLj and N as necessary.
It is manufactured from a material to which elements such as i, V, B, and Ti are added. It is considered that zero as an impurity should be kept as low as possible in order to maintain high toughness of the weld metal, and has been limited to 0.010% or less, preferably 0.005% or less. P was also similar to this. In conventional wires of this kind, in addition to the toughness and other properties of the weld metal mentioned above, important issues were the quality of the bead shape and prevention of blowhole formation. Also,
When painting to provide corrosion resistance after welding, it is desirable that the amount of slag produced be as small as possible and that it can be easily peeled off and removed. The inventors reexamined the alloy composition of the wire for gas-shielded arc welding from this point of view and found that what was conventionally considered common sense was not necessarily true.

[Problems to be solved by the invention]

An object of the present invention is to provide an improved gas-shielded arc welding wire based on new findings obtained by the inventors. That is, the improvement of the first invention and common to the whole is the improvement of the bead shape, the improvement of the second invention is additionally reducing blowholes, and the improvement of the third invention is is to reduce the amount of slag in addition to improving the bead shape, and the improvement of the fourth invention combines the second and third inventions to improve the bead shape, reduce blowholes, and reduce the amount of slag. The aim is to realize this. ■Dish Gosei

[Means to solve the problem]

The gas-shielded arc welding wire of the present invention that achieves the above-mentioned objects basically has C:O, 15% or less, s
+: 0.05-0.45% and Mn: 0.45
~2.0%, provided that 0.45%≦Mn≦0.7
In the range of 5%, Mn = 0.45 +0.75 (S
i −0,05) (%), and further 0.005
~0.030%, with the remainder essentially consisting of Fe. If the above quantitative relationship between Si and Mn (7) is shown in a graph, the first
As shown in the figure, the contents of both are selected so that they are within the trapezoidal area. The gas shielded arc welding wire of the second invention has C:
Contains 0.15% or less, s+: 0.05-0°45% and Mn: 0.45-2.0%, provided that in the range of 0.45%≦M≦0.75%, Mn = 0
．． 45 + 0.75 (Si -0,05) (%
), further containing 0.005 to 0.030% and P
:0.005 to 0.030%, and the balance is essentially Fe. The gas shielded arc welding wire of the third invention has C:
0.15% or less, Si: 0.05-0°45% and Mn: 0.45-2.0%, provided that in the range of 0.45%≦Mn≦0.75%, Mn = 0
．． 45 + 0.75 (Si -0,05) (%
), further containing 0.005 to 0.030%, Ti: 0.005% or less, and has an alloy composition in which the remainder is substantially Fe. And the gas shielded arc welding wire of the fourth invention has C: 0.15% or less and Si: 0.05 to 0.45.
% and Mn: Contains 0.45-2.0%, provided that in the range of 0.45%≦Mn≦0.75%, Mn = 0
．． 45 + 0.75 (Si -0,05) (%
), further containing 0.005 to 0.030% and P
:0.005-0.030%, Tt:0.
0.005% or less, and has an alloy composition in which the remainder substantially consists of Fe. (Function) The reason why the alloy components of the wire were selected as described above is as follows: C: 0.15% or less As mentioned above, when the C content increases, the toughness of the weld metal decreases. It is said that it is better to keep the value to a low value, and 0.15% is generally adopted as the upper limit.However, if strength is required, an appropriate amount, for example 0.2 to 0.
．． It is better to allow it to exist at about 7%. Si: 0.05~0.45% Mn: 0.45~2.0% Mn = 0.45 +0.75 (Si -0.05
) Since these are deoxidizing agents, a deficiency will cause blowholes. On the other hand, in order to obtain a good bead shape, that is, to make it as flat as possible, the above-mentioned quantitative relationship must be satisfied. Sl and Mn
If the village of is within the trapezoidal area of the graph in Figure 1, then
A good result is obtained in which the bead height to width ratio H/W shown in FIG. 2 is 0.45 or less. 0: 0.005 to 0.030% As mentioned above, it has been thought that a small amount of 0 is advantageous for the toughness of the weld metal, so efforts have been made to reduce the content as much as possible. However, within a range that does not have a substantially negative effect on toughness, that is, 0
．． It has been found that containing some amount of 0.3% or less is advantageous for improving the shape of the rod in relation to the above-mentioned 3i and Mnl. This effect is obtained when O content is 0.005% or more. P: 0.005-0.030% Similarly, the presence of P was also disliked as a cause of welding cracks, but it is better to include a small amount of P, with an upper limit of 0.03% that does not cause any problems, to reduce blowholes. The inventors have found that this effect is effective. This effect is due to the P
Obtained at contents above the limit of ≦0.005%. Tt: 0.005% or less A suitable amount of Ti has been considered a preferable component for suppressing spatter during gas shielded arc welding. on the other hand,
From the viewpoint of slag generation, it was confirmed that it is better not to include Ti. In the wire of the present invention, with the intention of improving the bead shape, the content of 3i and Mn, especially 3i, was selected to be lower than that of conventional wires, so slag is generated less than products containing large amounts of these. Although the amount is small,
By regulating Ti within the above limits, the amount of slag can be further reduced. (Example 1) Solid wires for gas-shielded arc welding (diameter 1.2 Jl! I11>) having the alloy composition shown in Table 1 were manufactured. Welding was carried out using each wire under the following conditions, and the bead shape was 180A -20V -80cmI/1lin Pulsed MAG welding Ar + 20% CO2 Bead-on-plate welding The results are also shown in Table 1.

[Example 2] Solid wire with the alloy composition shown in Table 2 (diameter 1°2 m)
) was manufactured and used for welding under the same conditions as Example 1. Bead shape and number of blowholes (pieces/100 m
The results of the investigation are also shown in Table 2. [Example 3] Solid wire (diameter 1°2 m) with the alloy composition shown in Table 3
> was manufactured and used for welding under the same conditions as Example 1. Table 3 also shows the results of examining the shape of the pead and amount of slag. The amount of slag (%) is a value determined by taking a photograph of the bead and measuring the proportion of the surface area (projected area) occupied by the portion to which slag is attached. [Example 4] Solid wire (diameter 1°2 m) with the alloy composition shown in Table 4
> was manufactured and used for welding under the same conditions as Example 1. Table 4 also shows the results of the bead shape, number of blowholes, and amount of slag. Table 1 Table 1 (Continued) The wire for gas shielded arc welding of the present invention is based on the first to fourth inventions, in which the amounts of 3i and Mn in the alloy composition are selected in a correlated manner. By containing an appropriate amount of O as well as I, the bead shape is improved and H/W≦0.4.
5, which satisfies the favorable conditions. In addition, in the second invention, the presence of an appropriate amount of P has an effect of reducing blowholes, and in the third invention, the amount of slag combined with the selection of the amount of 3i and Mn is achieved by regulating the amount of Ti. In the fourth invention, the effect of reducing blowholes due to the presence of an appropriate amount of P and the effect of reducing the amount of slag due to the regulation of the amount of Ti can be obtained. These wires can be used in accordance with conventional gas shielded arc welding techniques.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the 3i and Mn contents in the gas-shielded arc welding wire of the present invention. FIG. 2 is a sectional view schematically showing the height and width of the welding bead.

Claims (1)

[Claims] (1) C: 0.15% or less, Si: 0.05 to 0.45
% and Mn: 0.45 to 2.0%, provided that in the range of 0.45%≦Mn≦0.75%, Mn = 0.45 + 0.75 (Si-0.05) (%). A gas-shielded arc welding wire having an alloy composition further containing 0:0.005 to 0.030%, with the remainder substantially consisting of Fe. (2) C: 0.15% or less, Si: 0.05 to 0.45
% and Mn: 0.45 to 2.0%, however, in the range of 0.45%≦Mn≦0.75%, Mn = 0.45 + 0.75 (Si-0.05) (%). Furthermore, O: 0.005-0.030% and P
:0.005 to 0.030%, and the remainder is substantially Fe. (3) C: 0.15% or less, Si: 0.05 to 0.45
% and Mn: 0.45 to 2.0%, provided that in the range of 0.45%≦Mn≦0.75%, Mn = 0.45 + 0.15 (Si-0.05) (%). further contains O: 0.005 to 0.030%, Ti: 0.005% or less, and the remainder is substantially F.
A gas shielded arc welding wire having an alloy composition consisting of e. (4) C: 0.15% or less, Si: 0.05 to 0.45
% and Mn: 0.45 to 2.0%, provided that in the range of 0.45%≦Mn≦0.75%, Mn = 0.45 + 0.75 (Si-0.05) (%). Furthermore, O: 0.005-0.030% and P
:0.005-0.030%, Ti:0.00
A gas-shielded arc welding wire having an alloy composition of 5% or less and the remainder substantially consisting of Fe.