Conclusions(1) The N2-supplemented shielding gas facilitated the primaryaustenite formation in the GTAW WM and suppressed the Cr2Nprecipitation in the GTAW weld root. The FCAW joint presenteda higher austenite content than the pure Ar shielding GTAWjoint but lower than the 98% Ar + 2% N2shielding GTAW joint.And many O-Ti-Si-Mn inclusions were distributed in the FCAWWM.