Effect of welding energy on the corrosion and tribological properties of duplex stainless steel weld overlay deposited by GMAW/CMT process

Duplex stainless steels (DSS) show good mechanical properties, wear, corrosion resistance and fatigue strength. In order to decrease operational costs in paper and pulp industry, DSS is employed through weld overlay coatings on mild or low carbon steel components. In this work, the aim was to evaluate the DSS weld overlay properties obtained through deposition of ER 2209 duplex stainless steel alloy on a mild steel plate (ASTM A 516 Gr 60). The deposition was performed through GMAW/CMT welding process. The coatings were deposited using four heat inputs: 0.53, 1.01, 1.27 and 1.74 kJ/mm. Moreover, microstructural characterization by optical microscopy showed that heat input influences ferrite/austenite phase balance. Secondary austenite that precipitates due to the welding process in DSSs are Widmanstatten austenite (WA), grain boundary austenite (GBA), partially transformed austenite (PTA) and intragranular austenite (IGA). The amount of secondary austenite increases with welding energy input. The secondary austenite improves abrasive wear resistance while corrosion resistance is the lowest when welding energy is 1.74 kJ/mm.