Argon-Carbon Dioxide Mixtures -- Praxair's StarGold™ and Mig Mix Gold™ Blends

Argon/carbon dioxide blends are versatile mixtures for welding carbon, low-alloy and some stainless steels. Increasing the CO 2 content will increase weld penetration and bead wetting characteristics. At higher current levels and CO 2 content, increased spatter may result. Ar/CO 2 blends can be used to join a wide range of material thickness while utilizing a variety of modes of metal transfer.

Principal Applications

Ar/CO 2 blends are used for all kinds of structural steel, farm implements and machinery. Lower levels of CO 2 can be used for pulsed arc or spray arc welding, while higher levels > 20% are used for short arc welding and the shielding of some flux-cored wires.

	Composition %			Cylinder	Volume	Pressure	Part
Mixture	Ar	CO2		Style	(ft3)	(psig)	Number
StarGold™ C-5	95	5		T	338	2,640	AR STAR7-T
				K	252	2,200	AR STAR7-K
StarGold™ C-10	90	10		T	348	2,640	AR STAR9-T
				K	258	2,200	AR STAR9-K
StarGold™ C-15	85	15		T	357	2,640	AR STAR10-T
				K	264	2,200	AR STAR10-K
StarGold™ C-20	80	20		T	368	2,640	AR STAR13-T
				K	272	2,200	AR STAR13-K
StarGold™ C-25	75	25		T	381	2,640	AR STAR14-T
				K	280	2,200	AR STAR14-K
StarGold™ C-40	60	40		T	219	1,464	AR STAR15-T
				K	195	1,464	AR STAR15-K
StarGold™ C-50	50	50		T	157	1,168	AR STAR11-T
				K	177	1,168	AR STAR11-K
Mig Mix Gold™	>90	<10		T	344	2,640	AR STAR8-T
				K	255	2,200	AR STAR8-K

StarGold C-5 Gas Blend

This blend is used for pulsed spray transfer and short-circuiting transfer on a variety of material thicknesses. A 5% mixture may be used for GMAW-P of low alloy steels for out-of-position welding. The arc forces that develop give this mixture more tolerance to mill scale and a more controllable puddle than an argon-oxygen blend.

StarGold C-10 Gas Blend

This blend performs similarly to the StarGold C-5, but with increased heat input providing a wider, more fluid weld puddle in either short-circuit or spray transfer.

StarGold C-15 Gas Blend

This blend has been used for a variety of applications on carbon and low-alloy steels. In the short-circuit mode of transfer, maximum productivity on thin gauge metals can be achieved with this blend. This is done by minimizing the excessive melt-through tendency of higher carbon dioxide mixes, while increasing deposition rates and travel speeds. As the carbon dioxide percentages are lowered from the 20% range (maximum spray arc levels), improvements in deposition efficiency occur due to decreasing spatter loss. This blend will support the spray arc mode of transfer.

StarGold C-20 Gas Blend

May be used for short circuiting or spray transfer welding of carbon steel.

StarGold C-25 Gas Blend

This blend is commonly used for GMAW with short-circuiting transfer on low carbon steel. It was formulated to provide optimum droplet frequency on short-circuiting transfer using .035 and .045 diameter wire. GTS-Welco's StarGold C-25 operates well in high current applications on heavy base metal. It promotes good arc stability, weld pool control, and weld bead appearance. This blend will not support the spray type mode of metal transfer.

StarGold C-40 Gas Blend

This mixture is recommended for some flux-cored wires where improved arc stability and reduced spatter levels and offers improved welding penetration when compared to the StarGold C-25 mixture are desirable.

StarGold C-50 Gas Blend

Is often used for short arc welding of pipe, particularly when other contaminants are present in the surfaces to be welded.

Mig Mix Gold Gas Blend

This blend performs similarly to the StarGold C-5, but with increased heat input providing a wider, more fluid weld puddle in either short-circuit or spray transfer.