Consideration of the oxide particle–dislocation interaction in 9Cr-ODS steel

Abstract

The interaction between oxide particles and dislocations in a 9Cr-ODS ferritic steel is investigated by both static and in situ TEM observation under dynamic straining conditions and room temperature. The measured obstacle strength () of the oxide particles was no greater than 0.80 and the average was 0.63. The dislocation loops around some coarsened particles were also observed. The calculated obstacle strength by a stress formula of the Orowan interaction is nearly equaled to the average experimental value. Not only cross-slip system but also the Orowan interaction should be considered as the main interaction mechanism between oxide particles and dislocation in 9CrODS ferritic steel.

Keywords:

• ODS ferritic steel
• oxide particles
• dispersion strengthening
• in situ TEM straining experiments
• dislocation-obstacle interaction
• obstacle strength