Characterization of 14Cr ODS Steel Fabricated by Spark Plasma Sintering

Abstract

: Oxide Dispersion Strengthened (ODS) steel with a composition of Fe-14Cr-2W-0.2V-0.07Ta-1Al-0.3Y2O3 was fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). All of the investigations were performed on the as-SPSed ODS sample without further heat treatment. The microstructure, particles, and tensile properties of the ODS sample were analyzed. According to the results, both submicron-sized and micron-sized grains existed in the microstructure, showing a bimodal structure. The nanoparticles were homogeneously distributed in the matrix, and the nanoparticles in the ODS sample were mainly Y-Al-O composite oxides. Two kinds of Y-Al-O nanoparticles were identified: Y3Al5O12 particles with body-centered cubic structures and Y4Al2O9 particles with monoclinic structures. The size of the nanoparticles ranged from 2 nm to 61.5 nm, and the average size of the nanoparticles was 11 ± 2.7 nm. Except for the nanoparticles, large M23C6 particles that were detrimental to the ductility of the ODS sample were also identified. These large M23C6 particles possessed a long strip or rod-like morphology, and were generally distributed along the grain boundaries. The generation of cracks generally occurred in the region where the large M23C6 particles were located during the tensile test. The as-SPSed ODS steel possessed a ductile/brittle mixed fracture mode according to the fracture surfaces analysis.

Development of Ni-base oxide dispersion strengthened alloys using yttria-stabilised zirconia nanoparticles: powder preparation and spark plasma sintering processing

“…Oxide dispersion strengthened (ODS) nickel-based superalloys are suitable materials for eliminating challenges such as corrosion, erosion, oxidation and creep imposed by environmental conditions, including gas turbines [2] and heat exchanger pipes. ODS alloys can improve the mechanical strength at high temperatures and the corrosion resistance of hardened deposition alloys by adding sediment particles, which are very stable during temperature increases [3][4][5][6]. Mechanical alloying (MA) [7] is the most critical and commercial method of embedding oxide particles in a metal matrix.…”

Effects of Fe-Ions Irradiation on the Microstructure and Mechanical Properties of FeCrAl-1.5wt.% ZrC Alloys

“…However, due to the high aluminum content in FeCrAl alloy and the strong affinity between yttrium and aluminum, a large number of large-size Y-Al-O is generated, which deteriorates the properties of the material. [19][20][21]. ZrC possesses high chemical stability, shows a high melting point (~3540 • C), and does not react with Al, which can effectively avoid the formation of coarse particles.…”

Vacuum Hot Pressing of Oxide Dispersion Strengthened Ferritic Stainless Steels: Effect of Al Addition on the Microstructure and Properties

“…Oxide dispersion strengthened (ODS) ferritic-stainless steel (FSS) is widely used in the advanced fission and fusion reactors because of their excellent high-temperature properties [1][2][3][4][5][6][7]. In addition, the presence of highly rigid nano-sized oxide particles in ferritic ODS steels offers superior resistance to neutron irradiation.…”

“…Karak et al and Miller et al had reported that for elevated temperature applications, the BCC (body-centered cubic crystal) FSS exhibit good resistance to creep with higher thermal conductivity, superior oxidation resistance, excellent resistance to swelling, better tensile and compressive strength, and low coefficient of thermal expansion [9,10]. It has been reported that FSS suffers by embrittlement, known as 475 • C embrittlement when the materials are operated between 400-550 • C, which severely hampers the creep strength and swilling resistance [6]. To overcome such deficiencies, the FSS matrix is reinforced with nanoparticles especially oxides, which improves the strength of the composite and prevents grain boundary sliding both at room and elevated temperatures [11][12][13][14].…”