The GMAW process was developed in the United States 1948 and has since grown in importance to become a large and in the Western world even dominating arc welding process. High weld metal quality, cost efficiency and low fume emission rates are three of the keywords for the process. It is getting more and more common to weld duplex stainless steels with the GMAW process. The weldability of the duplex wire electrodes of today are almost as good as that of the austenitic electrodes. Especially when the pulsed arc technique is used. Suggestions for suitable shielding gases and welding parameters, as well as all weld metal properties are presented. 13% Cr, supermartensitic stainless steels are increasing in usage for flowlines. These steels have up to date been welded with the GMAW process and duplex stainless steel wire electrodes and mechanical properties of such weldments are reported.