Effect of zinc addition to PWR environment on corrosion behavior of FeNiCrAl alloy

Abstract

Alumina-forming duplex stainless steel (ADSS) which has been developed as a accident tolerant fuel cladding material to replace zirconium alloy and commercial stainless steel 316L and APM were immersed in simulated pressurized water reactor primary coolant environment with and without zinc addition. For all test material, oxide formed in zinc-added condition were thinner, sizes of external particle were smaller and number density of external particle were larger than that formed in zinc-free condition. From electrochemical analysis, larger corrosion resistance of oxide and less point defect densities were observed on oxide formed in zinc-added condition. However, ADSS showed less beneficial effect of zinc addition on corrosion behavior than other commercial stainless steel, and B2-NiAl which has low Cr contents might be a reason.