Liquid Air has a Blueshield 9 which is 7 1/2% Helium, 90% Argon and 2 1/2% Carbon Dioxide this is a quite common mix or blend for stainless steel, short circuit metal transfer GMAW (MIG). Other gas companies call it Tri-Mix because of the three part mixture. Be cautious about the term "Tri-Mix" there is a different three part mixture for Pulsed GMAW. It has Argon/Carbon Dioxide & Oxygen for steel welding. Check the flux cored wire manufacturers specification sheet for gas recommendation. The Blueshield 8 has 75% Argon and 25% Carbon dioxide, this is way too much carbon dioxide for Stainless Steels. Usually less than 2-5% Carbon Dioxide.

The TriMix (Old Standard) developed by Linde of years past was A-1025 which is a 90 He, 7.5 Ar, 2.5 CO2 mixture for short circuiting transfer of .035" diameter solid wire stainless steel. It's still the best gas (in my opinion) for short arc stainless. But if you need one gas to do both short arc and pulse Mig with solid wire then choose a 50 He, 38 Ar, 2% CO2 as the best compromise. The TriMix does not support stable pulse Mig transfer. In Europe and the rest of the world, 98 Ar, 2% CO2 is the most common gas for solid wire stainless short arc and pulse but it does not achieve the bead wetting in the short arc mode as easily as the Helium mixtures. For flux core SS use the manufacturer's recommendation. In most cases the C-25 (Ar-25% CO2) is the best but 100% CO2 can also be used if higher spatter and fume is tolerable.