ER385 is a high alloy austenitic stainless steel used to weld base metal of similar composition and with its extra low residual elements such as C, Si, S, P , and N improves the weld metal from hot cracking & fissuring.904L with it 20% Cr, 25% Ni,4.5% Mo and1.5% Cu is often found to manufacture or repair processing equipment, tanks, vessels, and piping that handles acetic & sulfuric acids and other chlorides. Also used for joining 317L & 904L to 304 or 316whereaddedcorrosion resistance is needed. Ar + 30% He +1-3 %CO2recommended

(Tri-mix gas = 90%He+7.5%Ar+2.5%CO2)