Oxide Dispersion Strengthened Research Articles

Effect of Nitrogen Atmosphere Annealing of Alloyed Powders on the Microstructure and Properties of ODS Ferritic Steels

Oxide Dispersion Strengthened (ODS) ferritic steels are promising materials for the nuclear power sector. This paper presents the results of a study on the sintering process using the Spark Plasma Sintering (SPS) technique, focusing on ODS ferritic steel powders with different contents (0.3 and 0.6 vol.%) of Y2O3. The novelty lies in the analysis of the effect of pre-annealing treatment on powders previously prepared by mechanical alloying on the microstructure, mechanical, and thermal properties of the sinters. Using the SPS method, it was possible to obtain well-densified sinters with a relative density above 98%. Pre-annealing the powders resulted in an increase in the relative density of the sinters and a slight increase in their thermal conductivity. The use of low electron energies during SEM analysis allowed for a fairly good visualization of the reinforcing oxides uniformly dispersed in the matrix. Analysis of the Mössbauer spectroscopy results revealed that pre-annealing induces local atomic rearrangements within the solid solution. In addition, there was an additional spectral component, indicating the formation of a Cr-based paramagnetic phase. The ODS material with a higher Y2O3 content showed increased Vickers hardness values, as well as increased Young’s modulus and nanohardness, as determined by nanoindentation tests.

Ultrahigh-strengthened intragranular κ-Al2O3 nanoparticles dispersed Mo composite prepared via SPS sintering of core-shell Mo nanocomposite powder

Oxide dispersion strengthening (ODS) is an effective method to improve the mechanical properties of Mo-based materials. However, the mechanical properties of traditional ODS-Mo composites are always limited by the coarsening and intergranular distribution of second-phase particles. In this work, an effective nano-reinforcement dispersion strategy was developed to fabricate an ODS-Mo composite with ultrafine grain and intragranular distribution of second-phase particles. Core-shell structural Mo nanocomposite powders, with internally distributed sub-10 nm Al2O3 dispersoids, were prepared by nano atomization doping (AD) followed by a chemical vapor transport growth strategy. Then, ODS-Mo composites with ultra-fine Mo grain (below 700 nm) and high-density intragranular κ-Al2O3 (below 20 nm) nanoparticles were prepared via spark plasma sintering (SPS), in which a coherent interface between κ-Al2O3 and Mo matrix was formed. The composites present remarkably improved hardness (above 500 HV), bend strength, and compressive yield strength (above 1664 MPa) at room temperature, with a suitable strain to fracture of 27.1%. The calculation of strengthening mechanisms indicates that the enhancement was mainly attributed to the intragranular κ-Al2O3 nanoparticles. This nano-sized reinforcement distributed within the grain can more effectively pin dislocations and achieve dispersion strengthening in ODS-Mo composites. Therefore, this strategy can efficiently construct intragranular second-phase nanoparticles and open up new avenues to fabricate high-performance ODS-Mo composites.

Atomic Diffusivities of Yttrium, Titanium and Oxygen Calculated by Ab Initio Molecular Dynamics in Molten 316L Oxide-Dispersion-Strengthened Steel Fabricated via Additive Manufacturing.

Oxide-dispersion-strengthened (ODS) steels have long been viewed as a prime solution for harsh environments. However, conventional manufacturing of ODS steels limits the final product geometry, is difficult to scale up to large components, and is expensive due to multiple highly involved, solid-state processing steps required. Additive manufacturing (AM) can directly incorporate dispersion elements (e.g., Y, Ti and O) during component fabrication, thus bypassing the need for an ODS steel supply chain, the scale-up challenges of powder processing routes, the buoyancy challenges associated with casting ODS steels, and the joining issues for net-shape component fabrication. In the AM process, the diffusion of the dispersion elements in the molten steel plays a key role in the precipitation of the oxide particles, thereby influencing the microstructure, thermal stability and high-temperature mechanical properties of the resulting ODS steels. In this work, the atomic diffusivities of Y, Ti, and O in molten 316L stainless steel (SS) as functions of temperature are determined by ab initio molecular dynamics simulations. The latest Vienna Ab initio Simulation Package (VASP) package that incorporates an on-the-fly machine learning force field for accelerated computation is used. At a constant temperature, the time-dependent coordinates of the target atoms in the molten 316L SS were analyzed in the form of mean square displacement in order to obtain diffusivity. The values of the diffusivity at multiple temperatures are then fitted to the Arrhenius form to determine the activation energy and the pre-exponential factor. Given the challenges in experimental measurement of atomic diffusivity at such high temperatures and correspondingly the lack of experimental data, this study provides important physical parameters for future modeling of the oxide precipitation kinetics during AM process.

Liquid metal compatibility of pre-oxidized FeCrAl in flowing Sn

A flowing Sn thermal convection loop (TCL) experiment was conducted in FeCrAlMo (Kanthal alloy APMT) tubing for 1000 h with a peak temperature of 400 °C. Oxide dispersion strengthened (ODS) Fe-(10–12)Cr-6Al and APMT specimens were exposed and all were pre-oxidized to form an external alumina scale. Unlike static exposures at 400° and 500 °C where pre-oxidation prevented dissolution, large mass losses were observed in the TCL hot leg after the specimens were cleaned in Li. The observed pitting suggests that localized failure of the pre-formed alumina surface oxide caused significant metal loss. Specimen mass gains were not observed on the cold leg implying that mass transfer did not occur and the small levels of Fe and Cr in the Sn after the experiment implies that Sn-rich phases may have formed. Post exposure room temperature tensile testing showed limited impact of the Sn exposure on the 12Cr ODS FeCrAl alloy, comparable to a 1000 h anneal in Ar at 400 °C. These results suggest that pre-oxidation is not sufficient to protect FeCrAl alloys in contact with flowing liquid Sn at 350°-400 °C.

Softening mechanism and failure behavior of 9Cr oxide dispersion strengthened steel resistance spot welded joint

Oxide dispersion strengthened (ODS) steel is one of the most promising materials for nuclear applications. However, there are fewer studies on the spot welding of ODS steel, and the softening mechanism of ODS steel resistance spot welded joint is unclear. The microstructural features of the ODS resistance spot welded joint was characterized to analyze the softening mechanism. The failure behavior and tensile shear performance were studied combined with finite element simulation. The results showed that the fusion boundary has the lowest hardness and the softening zone is divided into fusion zone(FZ) softening and heat affected zone(HAZ) softening according to different location in the joint. In FZ softening, the softening is mainly caused by the presence of δ-ferrite and fewer oxides as well as lower dislocation density. In HAZ softening, the softening is mainly caused by larger grains, less oxides. There are two types of failure, the fracture initiated at HAZ softening shows a brittle feature, while initiated at FZ softening shows a ductile feature. The softening leads to a reduction in tensile-shear strength. Thus, the control of softening zone is critical to improve the reliability of welded joints.

Positron annihilation lifetime spectroscopy of FeCr and FeCrAl oxide dispersion strengthened (ODS) alloys

Positron annihilation lifetime spectroscopy (PALS) was performed to characterize the interfacial nanostructure between the oxide particles and ferritic matrix in two types of oxide dispersion strengthened (ODS) alloys: FeCr dispersed with Y-Ti oxide nanoparticles and FeCrAl dispersed with Y-Al oxide nanoparticles. The spectra were precisely fitted and decomposed into three components with two trapping rates. Bulk lifetime approached the theoretical value of 107 ps by taking into account the positron trapping at two types of defects. Structural characterization was performed by coincidence Doppler broadening and high-resolution transmission electron microscopy (HRTEM), revealing that two-trapping defect clusters were closely associated with Y-Ti or Y-Al oxide particles. Trapping was not detected in the non-ODS alloys. Based on Kuramotos advanced theoretical work, the shorter annihilation lifetime (179–194 ps) could be ascribed to positron trapping at vacancies and divacancies localized under the misfit dislocations associated with Y-Ti or Y-Al oxide particles. The longer annihilation lifetime (301–323 ps) could be attributed to Ar-filled gas bubbles precipitated at the oxide particle-matrix interfaces. These results of PALS analyses were consistent with the HRTEM characterization.

Microstructural evolution and high-temperature oxidation behavior of oxide dispersion strengthened Inconel 625 superalloy fabricated by directed energy deposition

In the present study, wire arc-directed energy deposition (DED) technology was developed to fabricate the Oxide dispersion strengthened (ODS) Ni-based superalloy employing an Inconel 625 flux-cored wire including nano-La2O3 oxides. The microstructural evolution, mechanical properties and high-temperature oxidation behavior were systematically investigated. The results indicate that the melting and decomposition of La2O3 are thought to take place within the melt pool, followed by rapidly combining with Ti to re-precipitate as La2Ti2O7 oxides during DED. These oxides can serve as a highly effective nucleation site according to edge-to-edge matching calculation, resulting in the columnar-to-equiaxed transition and the refinement of grains. However, it is found that plenty of La elements are absorbed by the molten flux in the filler wire, resulting in the formation of slag and the loss of La. Consequently, the strength increases slightly due to the combined effects of precipitation strengthening and grain boundary strengthening. Furthermore, The ODS Inconel 625 sample can achieve a higher oxidation resistance after high-temperature oxidation at 900 °C for 150 h. The fine microstructure promotes the rapid formation of dense Cr2O3 oxide scales. On the other hand, the precipitation of La-rich oxides retards the outward transport of cation such as Ni, Fe and Nb, leading to the formation of a protective δ-Ni3Nb layer beneath the Cr2O3 layer to prevent the oxidation of matrix.

Unveiling deformation behavior and damage mechanism of irradiated high entropy alloys

The oxide dispersion strengthening (ODS) high entropy alloy (HEA) exhibits the high elevated temperature performance and radiation resistance due to severe atomic lattice distortion and oxide particles dispersed in matrix, which is expected to become the most promising structural material in the next generation of nuclear energy systems. However, microstructure and damage evolution of irradiated ODS HEA under loading remain elusive at submicron scale using the existing simulations owing to a lack of atomic-lattice-distortion information from a micromechanics description. Here, the random field theory informed discrete dislocation dynamics simulations based on the results of high-resolution transmission electron microscopy are developed to study the dislocation behavior and damage evolution in ODS HEA considering the influence of severe lattice distortion and nanoscale oxide particle. Noteworthy, the damage behavior shows an unusual trend of the decreasing-to-increasing transition with the continuous loading process. There are two main types of damage micromechanics generated in irradiated ODS HEA: the dislocation loop damage in which the damage is controlled by irradiation-induced dislocation loops and their evolution, the strain localization damage in which the damage comes from the dislocation multiplication in the local plastic region. The oxide particle hinders the dislocation movement in the main slip plane, and the lattice distortion induces the dislocation sliding to the secondary slip plane, which promotes the dislocation cross-slip and dislocation loop annihilation, and thus reduces the material damage in the elastic damage stage. These findings can deeply understand atomic-scale damage mechanism and guide the design of ODS HEA with high radiation resistance.

Flow behaviors and microstructural evolutions of nickel-based ODS superalloys during hot deformation

The hot deformation behaviors of nickel-based oxide dispersion strengthened (ODS) superalloys fabricated by mechanical alloying (MA) and hot extrusion (HEX) were investigated, the hot compression tests were performed to obtain true stress-true strain curves, the influence of strain rate and temperature connected with the microstructure evolution was analyzed, and the processing map and microstructure proposed at different strain levels was used to select its hot working parameters. The results illustrated that hot working conditions, especially the temperature, strongly influenced the grain structure. Specifically, deforming under high temperatures and low strain rate conditions enhances dynamic softening via dynamic recovery (DRV), dynamic recrystallization (DRX), and grain growth to consume the stored strain energy. In addition, the size and morphology of nanoparticles are not significantly changed before and after deformation, the nanoparticles and the matrix still maintain a good interface combination, and no interfacial mismatch such as nanosvoids between the nanoparticle and matrix is detected due to their outstanding interfacial binding ability and excellent ductility of matrix.

Microstructure and mechanical properties of oxide dispersion strengthened FeNiMnCr high-entropy alloy fabricated by spark plasma sintering

High-entropy alloys (HEAs) strengthened by dispersed oxide nanoparticles are considered potential structural materials used in advanced nuclear reactors. Herein, a novel Y-Si-O nanoparticle-strengthened near-equiatomic FeNiMnCr HEA was prepared via the powder metallurgy method. Microstructural characterizations revealed that the oxide dispersion-strengthened (ODS) FeNiMnCr HEA consisted of the face-centered cubic (FCC) matrix and high-density Y-Si-O nanoparticles (Y2SiO5 and Y2Si2O7). The average diameter and volume fraction of the nanoparticles were counted to be 21.3nm and 1.02%, respectively. The grain size was reduced from 10.13 μm of the FeNiMnCr HEA to 0.79 μm of the ODS FeNiMnCr HEA. The ODS FeNiMnCr HEA showed a yield strength of 1125MPa, an ultimate tensile strength of 1137MPa, and a moderate elongation of 8.3% at room temperature. At 500°C, the ODS FeNiMnCr HEA also had a high yield strength of 662MPa. Theoretical calculation showed that the high strength of the ODS FeNiMnCr HEA was mainly due to the grain boundary strengthening, dislocation strengthening, and precipitation strengthening.

A Novel Processing Route in the Mechano-Synthesis of Austenitic 58Fe25Ni17Cr Oxide Dispersion Strengthened Cast Alloy through Y<sub>2</sub>O<sub>3</sub> Pre-Linking

A powder metallurgical process has been applied to synthesize the FeNiCr+Y2O3 oxide dispersion strengthened (ODS) alloys. The composition of the reinforcing Y2O3 added into matrix was varied from zero to 2.0 percent weight. Raw powders were carefully weighed with a four-digit balance. Y2O3 powder was pre-linked into Fe powder as the dominant element in the matrix by manually ground for half an hour. Ni and Cr powders were then mixed evenly for the next a half hour to obtain FeNiCr+Y2O3 precursor. Avoiding agglomeration and grain coarsening, the precursor was uniformly homogenized by milling for 20 hours. The precursors were then compressed at an isostatic pressure of 100 kN to 12 grams of pellets each. To prevent sample erosion during smelting with an electric arc furnace (EAF), crystal growing mechanism by conventional sintering was performed at 900 °C for 2 hours. This strengthens the bonds between precursors in forming ODS alloys. The samples were then melt-casted in the arc by 4 times flips. As a result, the neutron diffraction analysis and SEM-EDS strongly reveal the austenitic crystal structure and Y2O3 oxide successfully dispersed in the cast-alloy respectively. The microstructures with Y2O3 oxide spread uniformly overall the cast-alloy surfaces.

The effect of chemical composition and heat parameter on Nano-sized precipitate dispersion characterization in ODS steels

Oxide dispersion strengthened (ODS) supersaturated solid solution alloy powders with different Y/Ti atomic ratios were formed by mechanical alloying (MA) method and then heat treated under different conditions. The morphology, phase composition, and particle size distribution were researched. The precipitate distribution densities and hardness values of alloy powders after heat treatment were measured at the same time by the SAXS method and hard tester. The results show that the morphology of MA alloy powders is irregular in shape and only a small amount of MA alloy powders is bigger than 30 μm. During the MA process, alloy elements are solid solutions in the matrix. The work-harden effect of alloy powders formed in the MA process would be eliminated during the heat treatment process. The chemical composition and heat treatment parameters are crucial effects on nano-sized precipitate distribution characterization in ODS steels. The ODS sample with a Y/Ti atomic ratio of 0.99 has the highest distribution density of oxide precipitates at 1.89×1022/m3 resulting in the highest hardness value during the heat treatment process. The sample with a Y/Ti atomic ratio of 0.42 has the highest distribution density of nanoclusters 7.32×1023/m3.

Development of a Diffusion Bonding Route for Joining Oxide-Dispersion-Strengthened (ODS) Steels for Nuclear Applications

Oxide-dispersion-strengthened (ODS) steels are candidate materials for components in current and future nuclear power plants. One of the issues with using ODS steels is the difficulty of joining them without loss of mechanical performance. In this study, austenitic ODS 316L stainless steel was diffusion-bonded to Inconel 718 superalloy. Having optimized the bonding conditions, a number of samples were made at 1200 °C with a bonding time of 1 hour and pressure of 10 MPa. Preliminary mechanical and microstructural analyses indicated the formation of a sound joint interface, despite slight grain growth in the ODS 316L. A post-bonding thermo-mechanical treatment (TMT) was conducted to refine and restore the microstructure of the ODS 316L. Comparative TEM investigations of the parent ODS alloy and the bonded samples (with and without TMT) along with statistical analyses showed that the Y–Ti–O oxide size distribution remains unaffected by the bonding and complementary TMT cycles, indicating stability of such particles even at very high temperatures and suitability of the devised route for joining the ODS 316L steel.

Investigation on different additions as candidates for nano-oxide particles in nickel-based ODS superalloys

Four nickel-based oxide dispersion strengthened (ODS) superalloys with the additions of YH2, Y2O3, La2O3 and CeO2 (denoted as ODS-Y1 ODS-Y2, ODS-La and ODS-Ce) are prepared, respectively. The tensile tests at temperatures ranging from room temperature (RT) to 1000 °C were conducted on them. In this work, by means of microstructure characterization and theoretical modeling, different strengthening mechanisms including grain boundary strengthening, solution strengthening, dislocations and dispersion strengthening, were estimated to contribute to the yield strength in different degrees, which would help to further enhance the tensile properties of alloys through nanoparticles optimization thereafter, and the formation and evolution mechanism of nanoparticles are discussed. The results show that ODS-Y1 has the smallest particles and the best comprehensive mechanical property in the tested alloys. The nanoparticles having M-Al-rich (M = Y, La, Ce) cores and Ti-O-rich shells structure are observed in nickel-based ODS superalloys, and the M-Al-O are preferentially formed, due to the higher diffusion rate of Al atom and high M/Al value. Then Ti and O atoms diffuse to the surface of nanoparticles, forming a core-shell structures in the later precipitation stages.

A comprehensive microstructural and transmission analysis on oxide dispersion-strengthened (ODS) alloys: Impact of erbium oxide (Er2O3) concentration on physical, structural, gamma-ray, and neutron attenuation properties

This study explores the impact of integrating varying concentrations of Erbium Oxide (Er2O3) into Oxide Dispersion Strengthened (ODS) alloys, specifically focusing on gamma-ray and neutron attenuation properties. Utilizing a 316L stainless steel matrix, Er2O3 was methodically incorporated in concentrations ranging from 1 % to 21 % by weight. The structural and radiation attenuation properties of the resultant alloys were comprehensively analyzed using techniques such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and experimental gamma-ray transmission studies. The results demonstrate a significant enhancement in gamma-ray shielding with increased Er2O3 content. This enhancement is quantitatively evidenced by increased linear attenuation coefficient, elevated effective Electron Density (Neff), reduced Half-Value Layers (HVL), and higher effective atomic numbers (Zeff). These findings are crucial for nuclear applications where efficient gamma-ray shielding is paramount. Conversely, a decrease in the effective removal cross section (ΣR) for neutron attenuation was observed with higher Er2O3 concentrations. This suggests a potential compromise in neutron shielding efficiency, attributed to the dilution of neutron-absorbing base elements in the alloy. Additionally, the study reveals notable changes in the microstructural properties of the alloys, including alterations in particle size, distribution, and agglomeration, influenced by varying Er2O3 concentrations. In conclusion, this research provides valuable insights into the design of ODS alloys for nuclear radiation shielding, highlighting the balance between gamma-ray attenuation and neutron shielding properties. The study's findings contribute to the development of advanced materials for safer and more efficient nuclear technology applications.

Effects of Cr and Si addition on the high-temperature oxidation resistance in high-Mn alumina-forming oxide dispersion strengthened austenitic steels

Oxide dispersion-strengthened (ODS) steels are promising candidates for constructing nuclear reactors. Considering a high-temperature environment, ODS austenitic steels could provide superior performance compared to the current ODS ferritic steels. To meet the reduced activation requirement, the compositions of ODS austenitic steels have to be carefully adjust. Currently, the authors focus on the ODS austenitic steels with the austenite stabilizer of Mn, and several amounts of Al are added to improve their high-temperature oxidation resistance. This study investigates the third-element effects of Cr and Si on the high-temperature oxidation resistance of high-manganese alumina-forming ODS austenitic steels. Generally, Si-containing steel exhibits superior oxidation resistance owing to the formation of a continuous inner layer of amorphous alumina. In contrast, the Cr-containing steel does not possess a continuous alumina layer, resulting in insufficient oxidation resistance. The reported phenomenon is believed to be a reference for the development of ODS austenitic steels in the future.

Laser powder bed fusion of oxide dispersion strengthened FeCrAl alloy: Processing and microstructural evolution

Optimizing and regulating the process parameters to form a uniform distribution of nanosized dispersoids remains a major challenge in additive manufacturing oxide dispersion strengthened (ODS) alloys. This study introduces the influence of scanning speed and laser power on the microstructure evolution of laser powder bed fusion (LPBF) ODS FeCrAl alloy. Low laser power and high scanning speed reduce the size of oxide particles and increase their number density. The energy density threshold is 83 J/m3, below which the powder fails to achieve complete melting, leading to the formation of defects during solidification. High density and large number of oxide particles were obtained for the printed samples under the parameters of 140 W laser power and 600 mm/s scanning speed. The average size and number density of oxide particles were ∼ 21.61 nm and ∼ 1.8 × 1020/m3, respectively. High scanning speed have a rapid cooling rate which affects the dislocation density and the average width of the columnar grains. Low laser power significantly weakens the 〈100〉 fiber texture, which is related to the degree of recrystallization in the remelted region. The core-shell oxides consisting of Y-Al-O and Y-Ti-O were distributed in the samples deposited at low and high laser powers, respectively. The formation of core-shell oxide particles in LPBF ODS FeCrAl alloys involves solid-state amorphization and recrystallization. This study can be a guideline to achieve materials with specific microstructure for ODS alloys.

Significant suppression of helium bubbles in oxide dispersion strengthened FeCrAl alloys irradiated by high concentration of helium

Oxide dispersion strengthened (ODS) FeCrAl alloys were successfully fabricated by various mechanical alloying time (10h and 40h), combined with spark plasma sintering (SPS) technique. To understand their helium irradiation resistance, two kinds of ODS FeCrAl alloys were implanted with helium ions at 400 keV in the fluence of 1 × 1021/m2 at 350 °C, 400 °C, and 450 °C to investigate the effect of high concentration helium on the materials in advanced nuclear reactors. The distributions of helium bubbles associated with the microstructural features were characterized by transmission electron microscope (TEM). The experimental results showed that both the helium bubble sizes and volume fractions increased with increasing the irradiation temperatures. The high sink strength of nano-oxides and small inter-oxides distance contributed to the good suppression of helium bubbles growth. In particular, we identified that the high-density nano-oxides with the small sizes (<10 nm) could sequester the helium into several (1–3) tiny bubbles to inhibit bubbles accumulating and coarsening both in elevated temperatures and high helium concentration. Additionally, grain boundaries demonstrated the weaker ability than nano-oxides to disperse helium bubbles, when compared helium irradiation resistance in ODS FeCrAl alloys and FeCrAl alloys. Eventually, ODS FeCrAl alloys in this study revealed the superior helium irradiation resistance than other studied alloys, making it promising to be one of the potential structural materials applicated in advanced nuclear reactors.

Contribution of Y2O3/Hf co-doping to alumina scale growth on oxide dispersion strengthened Co-based superalloy

Effect of Y2O3/Hf co-doping on the growth of the alumina scale formed on an oxide dispersion strengthened (ODS) Co-10Ni-20Cr-15Al (at%) superalloy at 900 °C in air was investigated. On both superalloys with and without Y2O3/Hf co-doping, a distinctive layered alumina scale consisting of an outer θ-alumina and an inner α-alumina was formed. Y2O3/Hf co-doping could reduce the oxidation growth rate of the θ- and α-alumina layers and improve the spallation resistance of the scale by suppressing the formation of interfacial pores. The reactive element effect in the θ-alumina has been initially elucidated in detail with the aid of 3D-AP characterization.

Optimization of microstructure and tensile properties for a 13Cr-1W ODS steel prepared by mechanical alloying and spark plasma sintering using pre-alloyed powder

An oxide-dispersion-strengthened (ODS) 13Cr-1W steel has been fabricated through mechanical alloying (MA) and spark plasma sintering (SPS) using pre-alloyed Fe-Cr-W-Y powder and TiO2 powder. Sufficient MA effects, indicated by homogeneous distribution of alloying elements and high level of lattice strain inside the powder, have been obtained within 20 h of high-energy ball-milling. Grain refinement of the bulk materials is successfully achieved by optimizing the sintering temperature and pressure during SPS. A fine-grained ODS steel with average grain size of 626.75 nm is prepared when sintered at 950 °C/80 MPa. Ultrafine oxide dispersoids, identified as Y2O3, Y2TiO5 and Y2Ti2O7, are observed homogeneously distributed in the steel matrix after annealing. They have a number density of 4.5 × 1022 m−3 and an average size of 11.15 nm. Tensile tests from room temperature to 700 °C are conducted to this ODS steel. It exhibits an ultimate tensile strength and a yield strength of 1559.60 MPa and 1352.82 MPa at room temperature, respectively. Due to a good combination of dislocation strengthening, grain boundary strengthening and precipitation strengthening, this alloy wins superior tensile properties over most of the commercial ODS steels and those reported in some previous studies.