Effect of high-temperature exposure on the mechanical properties of 18Cr-8Ni-W-Nb-V-N stainless steel

► Niobium stabilized 18Cr-8Ni austenitic steel was subjected to long-time aging. ► The main phases precipitated during aging are Z-phase and Laves-phase. ► Intragranular phases and solid solution are responsible for tensile strength. ► Intergranular particles affect impact toughness.