Nano-mesoscopic structural characterization of 9Cr-ODS martensitic steel for improving creep strength

This paper describes the effect on creep strength and microstructure of 9Cr-oxide dispersion strengthened martensitic steel (9Cr-ODS steel) produced by differences in titanium concentration and consolidation temperature. The increase of titanium concentration to 0.30-0.35 wt% was shown to provide considerable improvement of creep strength accompanied by the increase of residual-alpha ferrite. The elevation of hot-extrusion temperature degraded the creep strength, however, it appeared to increase the volume fraction of residual-alpha ferrite. The creep deformation process of 9Cr-ODS steel was discussed to explain these results based on microstructure observations. (c) 2007 Elsevier B.V. All rights reserved.