EFFECT OF MICROSTRUCTURE AND RELATIVE HUMIDITY ON ATMOSPHERIC PITTING CORROSION OF DUPLEX STAINLESS STEEL BENEATH MGCL2 DROPS

One of the main issues for intermediate-level nuclear waste (ILW) is atmospheric corrosion in stainless steel. The impact microstructure on pit shapes three orientations duplex steel DSS 2205 plate and relative humidity pits beneath MgCl2 drops determined through use four characterization tools: X-ray diffraction (XRD), Energy dispersive (EDX) analyses, Scanning electron microscopy (SEM), optical microscopy. top surface (LT) appears layered like an attack mostly hemispherical, while long transverse (LS) short (ST) planes reveal elongated strings. map scan EDX indicates mixed oxide inclusions MnS inclusion existing alloy XRD analyses present existence two-phase both austenite γ ferrite α peaks. shape area were influenced by (RH) change. At RH 35% trend 1-week exposure revealed a larger mouth than 45%. For same time RHs, seemed to be greater at droplet’s center edge droplet.