| Popis: |
A precipitation-hardened titanium-modified 316L stainless steel has been prepared by hot extrusion of nitrided rapidly solidified powder. The microstructure and properties of the rapidly solidified powder, internally nitrided powder and extruded bulk material have been investigated. The microstructure of extrudates consists of fine austenite grains and uniformly dispersed titanium nitride particles, as well as subgrains containing dislocation tangles. Finely dispersed nitride particles suppress grain growth by pinning the grain boundaries during recrystallization. A significant improvement in tensile properties, hardness and creep strength is obtained. Room temperature tensile strengths of more than 960 M Pa are obtained, with improvements in creep rupture life of 4–5 times compared with that of the conventional alloy. |
