Effect of Yttrium Contents on the Microstructure of a Hot-Rolled Tantalum-Containing 12Cr-ODS Steel

Abstract

Dual-phase oxide dispersion strengthened (ODS) steels of Fe−12Cr-xY (x = 0.1, 0.2, and 0.3 wt%) have been fabricated by casting, hot-forging and subsequent hot-rolling. Microstructure of the hot-rolled samples was carefully characterized by use of electron probe microanalysis (EPMA), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The results show that all the samples consist of ferrite phase with coarse fiber grains (elongated along the rolling direction) and martensite phase in the form of fine block grains. As the Y addition increases, the ratio of ferrite to martensite and density of low-angle boundaries (LABs) within the martensite and ferrite grains do not change significantly. The Y 2 O 3 particles introduced by self-oxidation during casting are survived without being dissolved or refined after hot-forging and hot-rolling. However, as the Y addition increases, the Y 2 O 3 particles tend to aggregate with fine M 23 C 6 and TaC carbides. The hardness of the sample with high Y additions is lower than that of the samples with none or low Y additions, which could be attributed to the aggregation coarsening of the yttria and TaC particles, resulting in a decrease in dispersion strengthening effect. The effect of Y additions on microtexture was also discussed.

A Combined Microscopy Study of the Microstructural Evolution of Ferritic Stainless Steel upon Deep Drawing: The Role of Alloy Composition

“…The texture fibre and the principal components of texture related to annealed specimens [25,26] were quantified using EBSD and Channel 5 and are listed in Table 2. The results show that the annealed specimens do not exhibit an α-fibre (also known as RD-fibre) texture [27]. However, a γ-fibre recrystallisation texture was significantly detected in both alloys.…”

Corrosion Behavior and Surface Treatment of Cladding Materials Used in High-Temperature Lead-Bismuth Eutectic Alloy: A Review

“…Ferritic/martensitic (F/M) steel, austenitic steels, and oxide dispersion-strengthened (ODS) alloys are considered to be promising candidate materials for these advanced nuclear systems [21][22][23][24][25]. Due to its high thermal conductivities, lower expansion coefficients, F/M steels, such as T91, HT-9, 1.4718, EP823, HCM12A, etc., can be considered for the generation IV nuclear reactors [26][27][28][29].…”