Nickel base filler metals are commonly used to maintain the corrosion resistance of superaustenitic and superduplex stainless steels in the welded condition. This implies, however, some negative points e.g. relatively low tensile strength, increased tendency for hot cracking and low corrosion resistance in strongly oxidizing media. A high nitrogen alloyed iron base filler metal has been developed aiming to overcome these problems. All-weld-metal samples and joint welds in some superaustenitic and superduplex steels have been made using GTAW and GMAW processes and their properties have been evaluated. The GTA welds showed acceptable quality free of pores, in GMA welds in some cases small pores were observed. In weldments in high strength superaustenitic and superduplex steels the tensile strength levels of the base materials were met. The critical pitting temperature evaluated on these weldments was 65°C and higher.