Microstructure refinement and strengthening mechanisms of a 12Cr ODS steel processed by equal channel angular extrusion

Oxide dispersion-strengthened steel PM2000 after dynamic plastic deformation: nanostructure and annealing behaviour

“…The swelling rate during the irradiation of the submicrometre-grained T91 steel after warm ECAE to a strain of 2.3 was found to be three times lower than that of a coarse-grained sample [3]. Compared to the structural refinement achieved by ECAE in [3,7], a much finer boundary spacing can be obtained if the deformation is performed at high strain rates. For instance, a lamellar structure with a boundary spacing of only 0.1 lm developed in a modified 9Cr-1Mo steel (T91) [8] due to compression via dynamic plastic deformation (DPD) [9] to a strain of 2.3 at a strain rate of 10 2 -10 3 s -1 .…”

“…One well-known way to refine the microstructure is via plastic deformation when original grains are subdivided by deformation-induced dislocation boundaries [5,6]. For example, structural refinement in the range of 0.3-0.6 lm was produced by equal channel angular extrusion (ECAE) in a ferritic/martensitic steel T91 and a 12Cr ODS steel [3,7]. The swelling rate during the irradiation of the submicrometre-grained T91 steel after warm ECAE to a strain of 2.3 was found to be three times lower than that of a coarse-grained sample [3].…”

Microstructure of HIPed and SPSed 9Cr-ODS steel and its effect on helium bubble formation

“…Moreover, nano-sized helium bubbles themselves could act as stable sinks for enhancing the recombination of vacancies and interstitials survived from cascade collision, effectively suppressing void swelling in irradiated materials. On the other hand, nano-oxides may also act as thermodynamically stable obstacles to impede dislocation and grain boundary movement, enhancing the mechanical properties of the steels even under high temperature [8,9]. Many comparative studies on swelling resistance or helium bubble distribution in conventional RAFM steels and ODS steels have been carried out and reported in the literature [10,11].…”

Bimodal Grain Size Distribution of Nanostructured Ferritic ODS Fe–Cr Alloys

“…In addition, the usual influence on mechanical properties, grain boundaries also increase the radiation resistance . In practice, a lack in reproducibility of the mechanical properties of these steels caused by an insufficient ability to control the microstructure evolution during the fabrication process has been a serious shortcoming . Lately, the production of reproducible material quality was achieved by Boulnat et al .…”