Welder MAG- welding inner tube.

Shielding Gases

For any application, it is important to choose the right shielding gas. Linde (former AGA) provides an extensive shielding gas range to meet all requirements.

The most important function of a shielding gas is to protect the molten weld pool and hot surrounding metal against ambient air, and to provide the electric arc with favourable conditions. Without such protection the metal would oxidise and the nitrogen in air would make the weld porous. Other factors that the shielding gas has an impact on include the speed of welding, corrosion resistance, mechanical properties and the working environment. Shielding gases therefore have vital properties both in terms of productivity and quality.

Each of the various components of shielding gases has its own effect. The components are combined with precision for optimal effect.

  • Shielding gases - Argon
    The base of most shielding gases. Argon is an inert gas. (Does not react chemically)
  • Shielding gases - Hydrogen
    Reduces oxidation and results in broader and deeper fusion when welding.
  • Shielding gases - Helium (He)
    Also an inert gas. Results in broader and deeper fusion and a better flow in the weld pool.
  • Shielding gases - Carbon dioxide
    An oxidising gas. As an additive it ensures arc stability and accurate welding profiles.
  • Shielding gases - Nitrogen
    Used as an additive when welding steels alloyed with nitrogen. Increases corrosion resistance.

Shielding Gases

Click on names to read more:
Argon

Purity better than 99.99%

- Used for TIG and plasma welding as well as a root protection when welding of all metallic materials. No ozone-reducing effect.

- Marking; EN ISO 14175-I1-Ar. Group I1

- Valve thread W 24.32 x 1/14" H exterior

Argon 4.6 (Argon Plus)

Purity better than 99.996%

- Used for TIG and plasma welding as well as a root protection upon welding of all material

- Argon 4.6 is recommended for welding of extra-sensitive material, where there is a very strict demand for gas purity, such as e.g. titanium and magnesium

- No ozone-reducing effect

- Marking; EN ISO 14175-I1-Ar. Group I1

- Valve thread W 24.32 x 1/14" H exterior

CORGON 18

Ar + 18% Carbon dioxide

- Intended for MIG welding of unalloyed and low-allowed steel with solid and cored wire electrodes

- With certain limitations the gas is also suitable for pulsed welding and for use as a shielding gas when welding stainless steels with rutile flux cored electrodes

- Gives smooth welds with little spatter in both short arc and spray arc

- Often suitable as a general shielding gas under less demanding conditions

- No ozone-reducing effect

- Marking; EN ISO 14175-M21- ArC-18. Group M21

- Valve thread W 24.32 x 1/14" H exterior

CORGON 25

Ar + 25% Carbon dioxide

- Used for MAG welding of unalloyed and low-alloyed steel with solid wires and flux cored electrodes

- With short arc welding, it gives a melt which is easy to control

- Tolerates impurities on the weld surface better than other mix gases in connection with spray arc welding

- Creates little spray, a smoother weld and a higher welding speed compared to pure carbon dioxide

- The most oxidizing of all mixed gases, creates the most slag of all

- Recommended particularly for short arc welding

- No ozone-reducing effect

- Marking; EN ISO 14175-M21-ArC-25. Group M21

- Valve thread W 24.32 x 1/14" H exterior

CORGON 8

Ar + 8% Carbon dioxide

- Used for MAG welding of unalloyed and low-alloyed steel with solid and cored wire electrodes

- Intended primarily for spray arc and pulse welding

- Provides high welding speed with little spatter and surface slag

- No ozone-reducing effect

- Marking; EN ISO 14175-M20-ArC-8. Group M20

- Valve thread W 24.32 x 1/14" H exterior

CRONIGON He

Ar + 1% oxygen + 30% He

- CRONIGON He is an all-round gas for MAG welding of the majority of stainless steels

- Suitable for all types of welding, i.e. short arc, spray arc and short pulsing

- CRONIGON He does not give a carbon pick-up in the weld pool, since it contains no carbon dioxide

- No ozone-reducing effect

- Marking; EN ISO 14175-M13-ArHeO-30/1. Group M13

- Valve thread W 24.32 x 1/14" H exterior

FORMIER 10

N2 + 10% H2

- Used as root protection gas in order to protect the weld’s rear in MIG/MAG, TIG and plasma welding

- Designed for all austenitic stainless steel, as well as for duplex and super duplex. Should not be used for welding of ferritic and martensitic stainless steel. Can be used as a root protection gas in the welding of unalloyed and low-alloyed steel

- Gives a cleaner and smoother rear to the weld compared to, for example, argon, because of hydrogen’s reducing properties, which not only results in better corrosion properties but also enables shorter purging times before welding.

- Nitrogen reduces the loss of nitrogen in the welding of nitrogen-alloyed steel types that also contributes towards improved corrosion properties in the finished weld.

- Marking; EN ISO 14175-N5-NH-10. Group N5.

- Valve thread W 21.8 x 1/14" V exterior

VARIGON H5

Ar + 5% hydrogen

- Can be used for both TIG and plasma welding and as a root protection gas in the welding of austenitic stainless steel. The gas is recommended primarily for plasma welding and root protection.

- Affords better penetration, higher welding speed and a cleaner weld than argon when used as a shielding gas

- TIG welding with VARIGON H5 is best carried out mechanically.

- As a root protection gas gives a cleaner and brighter surface than argon does.

- Marking; EN ISO 14175-R1-ArH-5. Group R1

- Valve thread W 21.8 x 1/14" V exterior

VARIGON H7

Ar + 7% hydrogen

- Can be used for both TIG and plasma welding and as a root protection gas in the welding of austenitic stainless steel. The gas is primarily recommended for use in plasma welding and as a root protection gas.

- Produces better penetration, a higher welding speed and a cleaner weld than argon and VARIGON H5 when used as a shielding gas

- TIG welding with VARIGON H7 is initially carried out mechanically

- As a root protection gas gives a cleaner and brighter surface than argon does

- Marking; EN ISO 14175-R1-ArH-7. Group R1

- Valve thread W 21.8 x 1/14" V exterior

VARIGON He50

Ar + 50% He

- Can be used for TIG and MIG welding of all material, but is primarily recommended for aluminum and its alloys as well as copper and its alloys

- Specially suited for MIG welding of aluminum in thicknesses between 4 and 8 mm

- Provides a somewhat better side penetration than argon both in MIG and TIG welding

- The welding speed can be raised by using VARIGON He50 compared to standard argon

- Marking; EN ISO 14175-I3-ArHe-50. Group I3

- Valve thread W 24.32 x 1/14" H exterior

VARIGON He70

Ar + 70% He

- Can in principle be used for TIG and MIG welding of all materials, but is primarily recommended for aluminum and its alloys and copper and its alloys

- Specially suited for MIG welding of aluminum and copper in thicknesses above 8 mm

- Provides better side penetration than VARIGON He50 both in MIG and TIG welding, and reduces the need for preheating

- The arc can, however, be more difficult to ignite than with VARIGON He50 in TIG welding

- Marking; EN ISO 14175-I3-ArHe-70. Group I3

- Valve thread W 24.32 x 1/14" H exterior