Gas Metal Arc Welding in AM: Gases and More

Getting Your Gas Right for GMAW (MIG or MAG welding)

Wide choice of welding gases and gas mixes tailored to different combinations of base material, filler and equipment to help you meet your job expectations

Benefit from the Most Used Fusion Joining Technology for Metallic Alloys

Gas metal arc welding (GMAW) processes such as metal inert gas (MIG) and metal active gas (MAG) are the most frequently used arc welding technologies worldwide.

The choice of welding gas has a big impact on the result of these welding jobs. Your base material, filler, equipment and expectations will determine the welding gas or blend best suited to your particular task.

We have welding gases for virtually every GMAW challenge and can guide you towards the best choice for your operations. Contact your Linde representative to check availability in your region.

GMAW Offers Multiple Advantages Including:

Cohesive joining - material continuity
Versatility - suited to most metallic alloys
Energy efficiency - above 90% in modern inverters
Rotational symmetry - flexibility for manual and robotic operations
Productivity - deposition rates + speed
Low investment, high value generation
Comprehensive standardization and industry acceptance
Electronically controlled processes and equipment ready for Industry 4.0

How Does GMAW Work?

The filler is melted directly in the welding arc and into the molten pool, which then solidifies to form a new joint. The welding arc is mainly formed by metal vapors resulting from overheating the endpoint of the filler wire, which is continuously fed. While the metal vapor-based welding arc makes GMAW and its variants energy efficient, it is also the source of hazardous emissions like welding fumes and radiation. These require dedicated occupational safety and health (OSH) protection measures. With the most frequently used GMAW variant, MAG welding of carbon steels, we have conducted extensive research into the benefits of substituting industry-standard gases with our specially developed welding gas mixes. Our tests confirm that these GMAW blends can reduce the emission of welding fumes directly at their source, in the arc.

Given this diversity of success factors and business expectations, one welding gas clearly cannot meet all needs.. Here at Linde, we have a solid understanding of how different gases and blends with different mixture ratios can impact GMAW outcomes. Our complete portfolio has the right solution for each job and priority.

Our experts can help you select the optimum GMAW gas for your particular task.

Contact your Linde representative

Getting the Mix Right

The base and filler material provide an initial indication of the welding gas or blend that is most compatible and might be most suited to the task at hand. The choice will be determined by the chemical reactivity of the gas components with the hot metal. As the name of some GMAW processes indicate, the process itself dictates the choice. Metal inert gas (MIG) welding typically relies on an inert process gas (where the active component is usually less than 0.05%), whereas metal active gas (MAG) welding uses an oxidizing gas (usually containing CO₂ and/or O₂ in the higher percentage range).

The table below lists the most common welding gases for GMAW.

Chemical reactivity of welding gas	Welding gas components	Typical GMAW applications
Inert. Doped gases with reactive components at levels below 0.05% are often also referred to as metallurgically "inert", even through they improve GMAW/MIG arc stability	Argon (Ar) Helium (He) Ar + He mixtures	GMAW/MIG welding of aluminum alloys GMAW/MIG welding of reactive alloys, e.g. based on titanium or nickel
Slightly oxidizing effect	0.5-5 % CO₂ and/or 0.5-3 % O₂ Balance Ar/He	GMAW/MAG welding of stainless steels and other high-alloyed materials Austenitic alloys (with addition of small amounts of hydrogen (H₂) or nitrogen (N₂) for metallurgical benefits) GMAW/MAG welding of thin sheet structural steel grades if aiming for reduction of oxides and lower fume emission rates
Medium oxidizing effect	5-25 % CO₂ and/or 3-10 % O₂ Balance Ar/He	GMAW/MAG welding of carbon, low alloyed and high-strength steels Spray and pulse arc transfer modes - with performance benefits in both
Strongly oxidizing effect	25-50 % CO₂ and/or 10-15 % O₂ Balance Ar	GMAW/MAG welding of carbon steels with heavy surface contamination, oxidation or coatings
Heavy oxidizing/carburizing effect	CO₂	GMAW/MAG welding of carbon steels in short-circuit or long arc transition modes, with fillers approved accordingly GMAW carbon steels if productivity, spatter and welding fume emissions are not a priority

Once the GMAW welding gases have been roughly categorized, the metal or alloy in question shapes the next step in the decision-making process. Visit our dedicated pages below to discover more.