Gas-shielded welding is a new welding technology based on the wide application of manual arc welding and submerged arc welding.
The commonly used welding protective mixture can be divided into three categories currently: two-component mixture, three-component mixture and four-component mixture.
Aluminium and aluminium alloys
Ar+He
Melting electrode ：26%-90%He
Tungsten electrode: Multiple mixing ratios up to 75% He + 25% Ar
Melting electrode &Tungsten electrode
High arc temperature, suitable for welding aluminum plate, can increase melting depth, reduce stomata, melt quickly.With the increase of He ratio, there is a certain spatter.
titanium zirconium and its alloys
Ar+He
Ar/He 75/25 inert
inert
Melting electrode &Tungsten electrode
Increases heat input.Suitable for jet arc, pulse arc and short circuit arc.
Ar/He 50/50 or 70/30
Ar/N2 80/20
inert
Melting electrode &Tungsten electrode
The input heat is greater than pure argon, which reduces the preheating temperature.
Input heat, but with a certain spatter
stainless steel high-strength steel
inert
For jet arcs and pulsed arcs
Used for jet arc, pulse arc and short circuit arc.
Carbon and low alloy steels
加O2（1%-5%）或20%
Ar/CO2（70-80）/（30-20）
Used for jet arc, high requirements for welding joints.
Good penetration for short circuit arc, jet arc and pulse arc
Carbon and low alloy steels
Ar/CO2 95/5
Ar/CO2/O2 80/15/5
加（20%-25%）O2
Excellent penetration for jet arc, pulsed arc and short circuit arc.
For jet arcs and short-circuit arcs
Ar+He
加（15%-20%）He
H2＜6%
Melting electrode &Tungsten electrode
Increasing heat input helps to suppress CO pores.
Common two-component mixtures are：
Ar-He
Ar-H2
Ar-O2
Ar-CO2
CO2
O2
N2
H2
Common three-component mixtures are:
Ar-He-CO2
Ar-He-N2
N2
Ar-He-O2
Ar-O2
CO
The four-component mixture is mainly composed of:
Ar
He
H2
O2
N2
CO2
etc.
