Influence of the microstructure on the tensile and impact properties of a 14Cr ODS steel bar
30 Oct 2012-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing (Elsevier)-Vol. 556, pp 696-703
TL;DR: In this article, a 14Cr oxide dispersion strengthened (ODS) steel bar was characterized by different microstructural techniques in order to evaluate the link between its microstructure and the mechanical properties achieved.
Abstract: A Fe–14Cr–1W–0.4Ti–0.3Y203 ferritic steel bar was characterised by different microstructural techniques in order to evaluate the link between its microstructure and the mechanical properties achieved. This bar was produced by mechanical alloying of a pre-alloyed gas atomised powder with yttria particles, followed by hot extrusion and subsequently annealing. The knowledge of the microstructure of this 14Cr oxide dispersion strengthened (ODS) steel allows for the explanation of the mechanical properties observed, such as the decrease of the ductility found in the transverse orientation of the bar, the existence of zig-zag crack paths in the broken specimens after the impact tests at low temperatures and the appearance of delaminations when the temperature is increased.
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TL;DR: In this paper, the effect of microstructural parameters on the microstructure, tensile properties from room temperature to 800°C and creep properties at 650°C has been investigated in a 14%Cr oxide dispersion strengthened (ODS) steel.
78 citations
TL;DR: In this paper, the authors focused on the relationship between microstructure and yield stress for an ODS Fe-9%Cr-based transformable alloy and a ODS ferritic alloy and found that particle strengthening, dislocation forest strengthening, and Hall-Petch strengthening are the major contributions.
62 citations
TL;DR: In this article, a transformable 9Cr oxide dispersion strengthened (ODS) steel was prepared by mechanical milling and consolidated by spark plasma sintering (SPS), and microstructural features in different fabrication stages were studied by X-ray diffraction, optical microscopy, scanning and transmission electron microscopy.
51 citations
TL;DR: In this paper, very fast heating rates were used to minimize porosity when controlling grain size and precipitation of dispersoids within a compacted material, which induced heterogeneous but fine grain size distribution and high density of nano-oxides.
Abstract: Oxide-dispersion strengthened (ODS) ferritic steels were produced by mechanical alloying and subsequent spark plasma sintering. Very fast heating rates were used to minimize porosity when controlling grain size and precipitation of dispersoids within a compacted material. Sintering cycles performed at 1373 K (1100 °C) induced heterogeneous, but fine grain size distribution and high density of nano-oxides. Yield strengths at room temperature and at 923 K (650 °C) are 975 MPa and 298 MPa, respectively. Furthermore, high-temperature ductility is much increased: total strain of 28 pct at 923 K (650 °C).
47 citations
TL;DR: In this article, the impact toughness properties of four kinds of high strength steel (HSS) were investigated with the nominal yield strength 460, 690, 800 and 960 MPa, respectively.
Abstract: Impact toughness properties of four kinds of high strength steel (HSS) were investigated with the nominal yield strength 460, 690, 800 and 960 MPa, respectively. The specialty of impact toughness among base metal, heat affected zone (HAZ) and weld metal were also compared and discussed. The correlations between the impact toughness of HSS and their nominal yield strength, plate thicknesses, testing temperature, welding methods were further studied. Combined with the scanning electron microscope (SEM) fracture surface observation, the microstructural features and corresponding fracture mechanisms have been analyzed. The results show that the impact toughness for HSS base metal deteriorated with the increasing nominal yield strength. The impact toughness of weld metal for HSS is much lower than that of the corresponding base metal. The impact performance of HAZ is discretized due to the welding thermal cycling on the HAZ where significant changes in grain structure and properties occur. The microcosmic fracture surface of HSS is examined to explain the reduction in impact performance under low temperature.
42 citations
References
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TL;DR: In this article, the authors reviewed the JNC activities on ODS steel development as "nano-composite materials" and concluded that the ODS-technology development achieved in the field of fast reactors should be effectively spun off to the fusion reactor first wall and blanket structural materials to allow for safe and economical reactor design.
673 citations
TL;DR: In this article, the differences and similarities of different ODS steels are explained in terms of the microstructures of the steels, and observations are explained using the properties of the ODS micro-structures.
478 citations
TL;DR: In this paper, the α to γ transformation in ODS martensitic steel has been successfully achieved by introducing the α-to-γ transformation in 13Cr-3W ODS ferritic steels.
288 citations
TL;DR: In this article, four ferritic alloys based on the composition Fe-14Cr-3W-0.4Ti were developed with a predominant dispersion of either oxide particles or nano-size Y-, Ti-, O-rich clusters, or nanoclusters (NC).
211 citations
15 May 2000-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: There are three possible mechanisms occurring in high temperature creep at low stresses: diffusion creep, Harper-Dorn creep and grain boundary sliding as discussed by the authors, and two sets of measurements that may be used to give an unambiguous identification of the dominant creep mechanism.
Abstract: There are three possible mechanisms occurring in high temperature creep at low stresses: diffusion creep, Harper–Dorn creep and grain boundary sliding. This paper examines the characteristics of these three processes and proposes two sets of measurements that may be used to give an unambiguous identification of the dominant creep mechanism. The approach is applied to published creep data and new measurements are reported for a Mg–0.55%Zr alloy which permit a clear distinction between diffusion creep and grain boundary sliding.
124 citations