Abstract
Weld metal toughness of ferritic stainless steels is improved by Ar+3.5%O2 GMAW shielding gas compared with Ar+20%CO2.C content in weld metal by Ar+3.5%O2 is lower than Ar+20%CO2.Grain boundary martensite is observed in microstructure of weld metal by Ar+20%CO2.