Which gas is stronger than iron

Gases for welding and forming

Which gas should I use for MIG / MAG welding? And how do the various gases react during welding? Most hobby welders have probably asked themselves these questions before. In this article we will introduce the different gases and their properties and tell you which gas is best for welding.

This article provides information on gas selection for the following welding processes:

Which gas is required for MAG welding?

All process gases of the CORGON series, the PERFORMANCE LINE; AR + O2 - Mixtures and CO2 suitable. The mixed gases differ in terms of welding behavior, welding data setting, seam formation, penetration and suitability for the welding position. The following table provides some information:

consequences onAr + CO2
CORGON series
Ar + CO2
Ar + O2
Normal position
Difficulty situations e.g. Pos.PG or PC

Safer with more CO2

Safer with more CO2

Sufficiently good for thin sheet metal
Can become critical - danger with bath flow
Degree of oxidation
(Slag formation)
Falling with
decreasing CO2-Salary
Falling with
decreasing CO2-Salary
porositySafer with
increasing CO2-Salary
Safer with
increasing CO2-Salary
Most sensitive
Gap bridging abilityGetting better with
decreasing CO2-Salary
Improved by the proportion of HeBad
Spatter ejectionReduced spatter with
decreasing CO2-Salary
Reduced spatter with
decreasing CO2-Salary
Notch effectLowThe leastIncreasing with sheet thickness

The shielding gases of the CRONIGON series are suitable for MAG welding of rust-resistant CrNi and Cr steels, duplex steels, Ni-based materials and special stainless steels. The process gases differ in Welding behavior, welding data setting, seam formation, surface oxidation, penetration and suitability for the welding position.

The CO2 - Contents <3 vol. % increase the arc stability without causing a reliable high C-firing in the weld metal.
As the He content increases, the arc becomes hotter and is more suitable for larger wall thicknesses and higher welding speeds.

The process gases of the CRONGON Ni series have a reduced proportion of active components and are mainly used for highly corrosion-resistant Ni-based materials.

Which gas is required for MIG welding?

Argon 4.6 is the standard process gas in MIG welding and is suitable for all non-ferrous materials.
Argon is used for welding, especially for those with good heat conductivity Aluminum and copper materials have related to additions of helium (VARIGON He series) Penetration improvement, pore security and welding speed proven beneficial.

TIG welding

Which gas is used for TIG welding?
The standard process gas for TIG welding is argon 4.6.
The gas used for TIG welding for all reactive materials such as titanium, tantalum, etc., for argon TIG welding, however, is quality 4.8. recommended.
The addition of hydrogen (VARIGON H series) increases the energy of the arc and increases penetration and welding speed.

The VARIGON H shielding gases may only be used for austenitic CrNi steels, nickel and Ni-based materials.
For aluminum and its alloys as well as for copper materials, additions of helium to increase the arc energy have proven effective.

The VARIGON He series therefore offers advantages in penetration behavior and welding speed with these materials with increased thermal conductivity. VARIGON He90 is required for direct current negative pole welding of Al and its alloys.

Plasma welding

With plasma welding, always two gas streams needed. Argon 4.6 is preferably used as the plasma gas. For the protective gases, admixtures of hydrogen for CrNi steels and nickel materials (VARIGON H series) have proven effective.


In many cases it is necessary to protect the weld root, e.g. when welding stainless CrNi steels to maintain corrosion resistance.

Forming gases are Nitrogen-hydrogen mixtures. In the case of titanium-stabilized steels, the welded-through root bead turns yellow due to the titanium nitride bond. Argon and VARIGON H welding process gases provide a remedy here. Root protection can also be required for other materials.
Argon is preferred for non-ferrous metals and the reactive materials titanium and tantalum.

Welding process gases for various materials

  • Argon = all materials
  • VARIGON H series: Ar / H2 -Mixtures = Austenitic CrNi steels, Ni and Ni-based materials
  • Forming gas: N2 /H2 -Mixtures = steels with the exception of high-strength fine-grain structural steels, austenitic steels (not Ti-stabilized)
  • VARIGON N series: Ar / N2 -Mixtures = austenitic CrNi steels, duplex and super duplex steels

Metal inert gas soldering

Metal inert gas brazing (MSG brazing) is a process for joining thin sheets that have been coated for corrosion protection.
CuSi and CuAl alloys are used as filler materials.

  • The process gases CRONIGON 2, CRONIGON S1 are used for coated sheets with the additional material copper silicon.
  • The process gases from the VARIGON He range are used for coated sheets with the additional material copper aluminum.
  • The process gases from the VARIGON He range are used for stainless steel.

Gas is urgently needed for welding, but the differences between the gases are often not immediately apparent and so it is difficult to choose the right gas.
Still, questions like: "Which gas do I use for stainless steel welding?" or "Which gas do I use for aluminum welding?", you can easily use our gas finder to determine the optimal gas.

We wish you every success with your next welding project!

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