Quantitative Nanostructure and Hardness Evolution in Duplex Stainless Steels: Under Real Low-Temperature Service Conditions

Abstract Duplex stainless steels are a group of widely used steels, because their attractive combination strength and corrosion resistance. However, these embrittle phase separation phenomenon in the ferrite when exposed to temperatures within miscibility gap. This manuscript investigates two commercial duplex steel (DSS) 22Cr-5Ni (2205 or UNS S32205), super-duplex (SDSS) 25Cr-7Ni (2507 S32750), its subsequent effect on mechanical property evolution. Long-term isothermal aging heat treatments were carried out at industrially relevant between 250 °C 350 for up 48,000 hours, quantitative measurements amplitude wavelength separated nanostructure obtained using Small-Angle Neutron Scattering (SANS). These quantifications as input parameters hardness models predict It is concluded that information from SANS combined with enables prediction evolution DSS low temperatures, which turn correlates embrittlement DSS.