Welding Stainless to Mild...

[CGCINC]

I will be TIG welding some stainless rod to mild Steel plate. I'm just not sure what filler rod to use?

I have 308L filler but a friend told me he would use 309L?

[CGCINC]

sorry, 304 Stainless to Mild Steel

[sportbike]

The 309L is preferred when welding a low 300-series to mild steel.

[CGCINC]

Alrighty, thanks!

[Spike]

As important as the filler rod, is the process used. The stainless and mild steel will absorb heat at different rates, and will also expand and contract at different rates. Stainless to Mild Steel is prone to cracking if not done correctly. It's important to preheat both metals, and to 'ease into' the welding puddle. Don't just hammer down on the pedal and start the weld puddle, use light heat and make a little circle to warm up the puddle area and gently bring the metals to a welding puddle, then weld slower, and don't pour on the heat like is normally done with steel. After welding, let up on the pedal slowly, and post heat the weld area, and turn your post gas way up to keep the argon flowing over the weld.