LAUSR

In this paper, stabilization using zirconium and niobium was investigated to reduce the effect of intergranular corrosion (IGC) in 5A grade cast duplex stainless steel. Computational thermodynamic software was used to determine the various heat treatment temperatures according to phase precipitation. Resistance to IGC was investigated by oxalic acid etch test and double-loop electrochemical potentiokinetic reactivation (DL-EPR) technique. The surface of the specimens was observed using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffractometry to evaluate the presence of various intermetallic phases prone to IGC. Oxalic acid etch test response has indicated the susceptibility, whereas the DL-EPR test has provided the degree of sensitization. The results revealed that zirconium-stabilized samples are more susceptible to IGC compared to the niobium samples. Earlier formation of niobium compounds led to the reduction of intergranular attack in the niobium-stabilized samples.