By Loïc Amadu, Welding Engineer, Friedlander Contracting International Ortec Group
Duplex and superduplex stainless steels are commonly welded with filler metals to obtain sound welds with good mechanical, metallurgical and corrosion resistance properties. Filler metal addition and heat input control are important factors to consider, but the diameter and thickness of the pipe must always been considered as main parameters. This study takes a closer look at the welding of small diameter and ‘thin’ wall thickness superduplex pipes with orbital GTAW, without filler metal, using an orbital closed head welding machine.