MIG welding stainless steel. ???
 

Alright, I have some stainless work that I need to do. I bought a small(10 cu. ft) bottle for doing the stainless work. The problem is that I had a brain fart and got Argon instead of tri mix. I have a Argon/CO2 bottle as well. Would the pure Argon be okay to use or should I see if they will trade out the Argon cylinder for a tri mix?

Also, I ordered some ER309 for doing the stainless to MS welds. Should I use that on the 304 to 304 welds also or use the more common ER308?

Re: MIG welding stainless steel. ???
 

ive used plain argon on SS and it worked fine... (mig)

Re: MIG welding stainless steel. ???
 

You can use any SS wire for welding ms, hcs, and ss

Wiki

200 Series—austenitic chromium-nickel-manganese alloys
300 Series—austenitic chromium-nickel alloys
Type 301—highly ductile, for formed products. Also hardens rapidly during mechanical working. Good weldability. Better wear resistance and fatigue strength than 304.
Type 302—same corrosion resistance as 304, with slightly higher strength due to additional carbon.
Type 303—easier machining version of 304 via addition of sulfur and phosphorus.
Type 304—the most common grade; the classic 18/8 stainless steel.
Type 309— better temperature resistance than 304
Type 316—the second most common grade (after 304); for food and surgical stainless steel uses; Alloy addition of molybdenum prevents specific forms of corrosion. Also known as "marine grade" stainless steel due to its increased resistance to chloride corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.
Type 321— similar to 304 but lower risk of weld decay due to addition of titanium
400 Series—ferritic and martensitic chromium alloys
Type 408—heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel.
Type 409—cheapest type; used for automobile exhausts; ferritic (iron/chromium only).
Type 410—martensitic (high-strength iron/chromium). Wear resistant, but less corrosion resistant.
Type 416— easy to machine due to additional sulfur
Type 420—"Cutlery Grade" martensitic; similar to the Brearley's original "rustless steel". Also known as "surgical steel". Excellent polishability.
Type 430—decorative, e.g., for automotive trim; ferritic. Good formability, but with reduced temperature and corrosion resistance.
Type 440—a higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention when the steel is heat treated properly. It can be hardened to Rockwell 58 hardness, making it one of the hardest stainless steels. Also known as "razor blade steel". Available in three grades 440A, 440B, 440C (more common) and 440F (free machinable).
500 Series—heat resisting chromium alloys
600 Series—martensitic precipitation hardening alloys
Type 630—most common PH stainless, better known as 17-4; 17% chromium, 4% nickel