JPS5950992A - Welding wire - Google Patents

Abstract

PURPOSE:To obtain a welding wire which easily realizes spray transfer and produces extremely less spatters in a wire for pulse MAG welding, by specifying a material compsn. CONSTITUTION:A selding wire contains 0.2-1.0% Si, 0.5-3.0% Mn <=0.3% Ti, and consisting of <=0.15% C, <=0.20% Cr, <=0.010% Al, <=0.010% REM, <=0.020% O, <=0.020% N, <=5cc/100g H and the balance Fe. It is possible to add <=10% Ni or/and <=2% Mo to said compsn. if desired. The strength in the weld zone is much improved by the addition of the above-mentioned components.

Description

[Detailed description of the invention] The present invention relates to improvements in wire used for welding steel.

In copper arc welding, MAG welding, which uses a mixed gas of CO2 + Ar as the rolled gas, is becoming widely popular because it is suitable for automation of work, but among them, pulsed MΔG welding, which supplies welding current as a rectangular wave pulse, is It is recognized as a powerful technology because it produces high-quality welds and produces less spatter.

In order to take advantage of the advantage of pulsed MAG welding that there is less spatter, it is necessary to eject one droplet of wire per pulse.
It is necessary to achieve so-called spray transition, and for this purpose it is necessary to use a welding wire that stably generates an arc corresponding to the pulse.

An object of the present invention is to provide a welding wire that can easily achieve spray transfer when used in pulsed MAG welding and generates extremely little spatter.

The welding wire for pulsed MAG welding of the present invention is characterized by the selection of material composition, including Si: 0.
2 = 1.0%, Mn: 0.5-3.0% and '
]'i: Contains 0.3% or more, C: 0.15%
I-1・, Cr.

0.20% or less, /\l': 0.010% or less, R
EM or lanthanide rare elements: 0.010%
Below, 0: 0.020% or less, N: 0.020
% or more and H: 5 cc/100.9 or less, the welding wire is made with a composition in which the remainder substantially consists of Fe.

Among the above essential additive elements, Sl is a deoxidizing agent and is required in an amount of 0.2% or more in order to improve oxidation resistance, and is useful for stabilizing the arc. If more than 1% is present, the toughness will be low.
and causes high-temperature embrittlement. Since Mn is also a deoxidizing agent and contributes to improving the strength of the welded part, Mn is added in an amount of 0.5% or more. If the content becomes excessive, the bead shape will be impaired, and the monofacial corrosion resistance and processability will be reduced. 1゛l not only stabilizes the arc and reduces spatter, but also improves the strength of the weld.

However, when added in excess, it reduces the ductility of the weld metal.

C1-9Δp and REM, if present in excess of the above-mentioned limits, will make the arc unstable and cause spatter, so they must be regulated individually.

O, N, and H are originally gas-based elements, and C generates gas under welding conditions and both tend to induce spatter, so they should be within the above-mentioned limits.

If desired, in the above composition, Ni: 10% or less, Mo: 2%, where 4=Ail of the welding 1 thread of the present invention
Either one or both of the following can be used. The addition of these elements can further improve the strength of the weld.

Pulsed MΔG welding operations using the welding wire of the invention may be carried out according to known techniques.

Steels to be welded include various types of mild steel, carbon steel, and low alloy steel.

Welding wire with a diameter ↑, 2 mm with the composition shown in the example table
was manufactured. Use these welding wires [, thickness l
5 Bead welding on a tn, m mild steel plate,
It was conducted under the following conditions.

Norvi gas: Ar + 20% CO2 Arc current: 250 A pulse 200 pulses/sec Bead length: 20 crn The sputter depth was visually evaluated, and the next 3 stages 1
Divided into authors. , Δ゛ is almost non-existent.

B: Although it is less than in the case of conventional technology, it is still significant.

C: No difference from conventional technology.

The results are also shown in the table. In addition, no defects were found in the welding itself in any case. /ζ/ When a bending test was conducted with the weld bead facing up and a bending radius of 32 mm, an excessive amount of 1゛1 was found.
No. 5 had cracks.

46-

Claims (1)

[Claims] (11Si: 0.2 = 1.0%, Mn:
0.5-3.0% and Ti: 0.3% or more], C: 0.15% or less, Cr: 0.20% or less, Ap: 0.010% or more, REM :0.
010% or more, ○: 0.020% or less, N: 0
．． 020% and I]: 5 cc/1009 or less, a welding wire for /ζ pulse MΔG welding, with a composition of which the remainder is substantially Fe. +21 -l1 In addition to the above composition, further Ni: 10
% or less and (map ξ) Mo: 2% or less.