Fatigue life and microstructure of ODS steels

Three high Cr steels prepared by powder metallurgy and strengthened by fine oxide particles were subjected to low cycle fatigue testing at room temperature and microstructural characterisation. While the strength of the three materials is roughly comparable, the strong variance in the fatigue life of studied materials was measured. The reasons for this difference are discussed in terms of microstructure and differences in the crack nucleation mechanisms and early crack growth.