scholarly journals Microstructure and Mechanical Properties of 14Cr-ODS Steels with Zr Addition

2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Oxide Dispersion Strengthened ◽  
Nominal Composition ◽  
Ods Steel ◽  
Zr Addition ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Ods Steels ◽  
The Impact

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.

Role of Cr and Ti Contents on the Microstructure and Mechanical Properties of ODS Ferritic Steels

2008 ◽  
Vol 59 ◽  
pp. 308-312 ◽  
Author(s):  
Zbigniew Oksiuta ◽  
Nadine L. Baluc
Keyword(s):  
Mechanical Properties ◽  
Uniform Elongation ◽  
Hot Isostatic Pressing ◽  
Charpy Impact ◽  
Oxide Dispersion Strengthened ◽  
Total Elongation ◽  
Nano Particles ◽  
Ferritic Steels ◽  
Ods Steel ◽  
Microstructure And Mechanical Properties

Six oxide dispersion strengthened (ODS) ferritic steels, with the composition of Fe-(12-14)Cr-2W-(0.1-0.3-0.5)Ti-0.3Y2O3 (wt.%), have been prepared by mechanically alloying elemental powders of Fe, Cr, W, and Ti with Y2O3 nano-particles followed by hot isostatic pressing. The influence of the chemical composition on the microstructure and mechanical properties of various materials was studied. It was found that the chromium content has a significant influence on the microstructure and mechanical properties of the compacted ingots. The 14Cr ODS steel exhibits slightly higher ultimate tensile strength and yield strength values than the 12Cr ODS steel. The total elongation and uniform elongation of both materials, in general, decrease with raising the test temperature, although in the case of the 12Cr ODS steel the elongation is about 30% higher than that of the 14Cr ODS material. In what concerns the effect of titanium content it can be concluded that variations between 0.1 and 0.3% have no visible effects on the microstructure and Charpy impact properties of compacted specimens. However, the microstructure of specimens with 0.5%Ti contains large TiO2 particles with a size in the range of 50-500nm, which have detrimental influence on the mechanical properties of that material.

Phenomena Leading to a Modification of the Nano-Sized Structure during Resistance Upset Welding of ODS Steel Cladding

2012 ◽  
Vol 706-709 ◽  
pp. 977-982 ◽  
Author(s):  
Fabien Corpace ◽  
A. Monnier ◽  
A. Poulon Quintin ◽  
J P. Manaud
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Oxide Dispersion Strengthened ◽  
Fusion Welding ◽  
Oxide Dispersion ◽  
Fuel Cladding ◽  
Ods Steel ◽  
The Matrix ◽  
Ods Steels ◽  
Two Stages

ODS steels (Oxide Dispersion Strengthened) are candidate materials for fuel cladding in Sodium Fast Reactors (SFR). These materials have good mechanical properties at high temperature due to a dispersion of nanometer-sized oxides into the matrix. Previous studies have shown that melting can induce a decrease of the mechanical properties at high temperatures due to modifications of the nanometer-sized oxide dispersion. Therefore the fusion welding techniques are not recommended and the solid state boundings has to be evaluated. This study is focused on resistance upset welding. Welding experiments and numerical simulations are coupled. The numerical simulation is developed in order to have a better understanding of the thermal and the mechanical phenomena occurring during the welding process. The simulation shows that the welding steps can be divided in two stages. First, the temperature of the contact between pieces increases. Second, the heat generation is mainly located in the cladding leading to the collapse and forging the pieces. The microstructural observations confirm that the major deformation is located in the cladding. Oxide dispersion modification and dynamical recrystallisation has been found for welds achieved with a non optimized process parameter set. The deformation and the temperature seem to be of prime importance in the modification of the oxide dispersion.

scholarly journals Effect of Oxygen Content on Microstructure and Tensile Properties of a 22Cr-5Al ODS Steel

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2241
Author(s):  
Yukun Zhang ◽  
Yingjie Yan ◽  
Yazhong Zhai ◽  
Wei Qin ◽  
Hongyan Che ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Grain Boundaries ◽  
Oxygen Content ◽  
Hot Isostatic Pressing ◽  
Oxide Dispersion Strengthened ◽  
Ods Steel ◽  
The Matrix ◽  
Ods Steels ◽  
Effect Of Oxygen ◽  
Content Of Oxygen

The high tensile strength and irradiation resistance of oxide dispersion strengthened (ODS) ferritic steels is attributed to the ultrafine and dispersed oxides within the matrix. The high content of oxygen and yttrium is critical for the formation of dense Y-rich oxides. However, only few studies have reported the effect of oxygen content on the microstructure and mechanical properties of ODS steels. Herein, we employed gas atomization reactive synthesis to prepare pre-alloy powders and then hot isostatic pressing (HIP) to consolidate two 22Cr-5Al ODS steels with different oxygen content. Our results showed Y-rich precipitates at and near grain boundaries of the as-HIPed alloys. Moreover, with the oxygen content increasing from 0.04 to 0.16 wt%, more precipitates precipitated in the as-HIPed alloy, and the ultimate tensile strength of the alloy was improved. However, increasing the oxygen content to 0.16 wt% led to formation of stripe and chain precipitates at and near grain boundaries, which caused a partial intergranular fracture of the as-HIPed alloy.

scholarly journals Development of New 14 Cr ODS Steels by Using New Oxides Formers and B as an Inhibitor of the Grain Growth

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1344
Author(s):  
Alberto Meza ◽  
Eric Macía ◽  
Andrea García-Junceda ◽  
Luis Antonio Díaz ◽  
Paul Chekhonin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Electron Backscatter Diffraction ◽  
Oxide Dispersion Strengthened ◽  
Complex Oxide ◽  
Tensile Tests ◽  
Processing Route ◽  
Prealloyed Powder ◽  
Ods Steel ◽  
Ods Steels

In this work, new oxide dispersion strengthened (ODS) ferritic steels have been produced by powder metallurgy using an alternative processing route and characterized afterwards by comparing them with a base ODS steel with Y2O3 and Ti additions. Different alloying elements like boron (B), which is known as an inhibitor of grain growth obtained by pinning grain boundaries, and complex oxide compounds (Y-Ti-Zr-O) have been introduced to the 14Cr prealloyed powder by using mechanical alloying (MA) and were further consolidated by spark employing plasma sintering (SPS). Techniques such as x-ray diffraction (XRD), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to study the obtained microstructures. Micro-tensile tests and microhardness measurements were carried out at room temperature to analyze the mechanical properties of the differently developed microstructures, which was considered to result in a better strength in the ODS steels containing the complex oxide Y-Ti-Zr-O. In addition, small punch (SP) tests were performed to evaluate the response of the material under high temperatures conditions, under which promising mechanical properties were attained by the materials containing Y-Ti-Zr-O (14Al-X-ODS and 14Al-X-ODS-B) in comparison with the other commercial steel, GETMAT. The differences in mechanical strength can be attributed to the precipitate’s density, nature, size, and to the density of dislocations in each ODS steel.

Effects of Consolidation Process on the Microstructure and Mechanical Properties of ODS Ferritic Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 507-512 ◽  
Author(s):  
Tong Liu ◽  
Hai Long Shen ◽  
Tong Wen Zhang ◽  
Mu Zhu ◽  
Cheng Gong Qin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Hot Isostatic Pressing ◽  
Oxide Dispersion Strengthened ◽  
Consolidation Process ◽  
Ferritic Alloy ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Oxide Particles

The oxide-dispersion-strengthened (ODS) ferritic alloy powders (Fe-14Cr-3Al-2W-0.1Ti-0.35Y2O3) were prepared by mechanical alloying (MA) at a rotation speed of 720 rpm for 24 h. All the elements were mixed homogenously in the powder, and Cr and Al dissolved in α-Fe after MA. The bulk samples were produced by spark plasma sintering (SPS) at 950 and 50 MPa and by hot isostatic pressing (HIP) at 1150 and 130 MPa, respectively. The SPS sample showed a tensile strength of 730 MPa and a poor ductility due to the existence of pores in microsize. The HIP sample had a high tensile strength of 980 MPa, yield strength of 710 MPa and elongation of 10.3 %. The excellent mechanical properties of the HIP sample was due to the small grain size of the matrix of about 400 nm and the fine oxide particles of 5-40 nm.

Microstructure and Mechanical Properties of Spray Deposited W9Mo3Cr4V High Speed Steel

2011 ◽  
Vol 391-392 ◽  
pp. 714-718
Author(s):  
Rui Zhou ◽  
Jian Fei Sun ◽  
Ying Jun Yang
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
High Speed ◽  
Bending Strength ◽  
Spray Deposition ◽  
High Speed Steel ◽  
Solidification Shrinkage ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
The Impact

Microstructure and mechanical properties of W9Mo3Cr4V high speed steel fabricated by spray deposition have been studied. Spray deposited W9Mo3Cr4V high speed steel has a typical equiaxed structure which is finer and more homogeneous with a grain size of 20-30 micrometer compared with conventional casted counterparts. There are pores in the matrix of the deposited steel, which involve gas porosity, filling porosity and solidification shrinkage. As-deposited high speed steel is mainly composed of martensite, austenite and carbides which comprise MC carbide and M6C carbide. Mechanical properties show that the hardness and bending strength of the as-deposited steel are higher than that of the conventionally casted ones. However, impact toughness of the high speed steel is lower than that of the conventionally casted steel, which can be attributed to the existence of porosities and M6C carbides which reduce the impact toughness of high speed steels.

scholarly journals First-Principles Calculations of Y-Si-O Nanoclusters and Effect of Si on Microstructure and Mechanical Properties of 12Cr ODS Steel in Vacuum Sintering System

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 155
Author(s):  
Feng Su ◽  
Guangtao Xu ◽  
Zhenhua Yao ◽  
Huachen Liu ◽  
Yikun Chen
Keyword(s):  
Mechanical Properties ◽  
First Principles ◽  
Density Functional ◽  
Sintering Temperature ◽  
Oxide Dispersion Strengthened ◽  
Binding Energies ◽  
Primary Role ◽  
Vacuum Sintering ◽  
Ods Steel ◽  
Ods Steels

High density of thermally stable Y-Si-O nanoparticles dispersed in the Fe matrix play a primary role in oxide dispersion strengthened (ODS) steel. In this study, the binding energies of solutes Y, O and Si with vacancies have been calculated in the framework of first-principles density functional theory. According to the calculations, any two solutes of Y, O and Si bound with each other strongly in the second nearest neighboring (NN) sites while not in 1NN. A vacancy (v) bounds strongly with Y and O in 1NN site. The binding sequence of solutes with v followed O-v → Y-v → Si-v, and the affinity of Y, Si and v with O followed O-Y → O-v → O-Si. The nucleation mechanism of Y-O-Si nanoclusters was determined, which gave the feasibility of adding Si to ODS steels. The core (consisting of Si and O)-shell (enriched Fe and Cr) structure of the microparticles was found in ODS steels containing Si, fabricated by mechanical alloying (MA) and vacuum sintering. Moreover the nanoparticles of monoclinic cubic Y2O3, Y2SiO5 and Y2Si2O7 with sizes of 5 ~ 12 nm were observed in ODS steel. Si reduced the sintering temperature by maximizing densities and mechanical properties at a lower sintering temperature. The steel with 3 wt% Si was sintered at 1280 °C, exhibiting the best comprehensive mechanical properties. The tensile strength, hardness and relative density were 1025 MPa, 442.44 HV and 95.3%, respectively.

scholarly journals Effect of Small Variations in Zr Content on the Microstructure and Properties of Ferritic ODS Steels Consolidated by SPS

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 348 ◽  
Author(s):  
Andrea García-Junceda ◽  
Eric Macía ◽  
Dariusz Garbiec ◽  
Marta Serrano ◽  
José M. Torralba ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Heating Rates ◽  
Ultrafine Grains ◽  
Ods Steel ◽  
Plasma Sintering ◽  
Final Microstructure ◽  
Spark Plasma ◽  
Ods Steels

Two different zirconium contents (0.45 and 0.60 wt.%) have been incorporated into a Fe-14Cr-5Al-3W-0.4Ti-0.25Y2O3 oxide dispersion-strengthened (ODS) steel in order to evaluate their effect on the final microstructure and mechanical properties. The powders with the targeted compositions were obtained by mechanical alloying (MA), and subsequently processed by spark plasma sintering (SPS) at two different heating rates: 100 and 400 °C·min−1. Non-textured bimodal microstructures composed of micrometric and ultrafine grains were obtained. The increase in Zr content led to a higher percentage of Zr nano-oxides and larger regions of ultrafine grains. These ultrafine grains also seem to be promoted by higher heating rates. The effective pinning of the dislocations by the Zr dispersoids, and the refining of the microstructure, have significantly increased the strength exhibited by the ODS steels during the small punch tests, even at high temperatures (500 °C).

scholarly journals Influence of Zr addition on the microstructure and mechanical properties of 9CrTi-ODS steels

2021 ◽  
Vol 29 ◽  
pp. 101101
Author(s):  
Yingjie Wang ◽  
Shuai Xu ◽  
Haodong Jia ◽  
Zhenfeng Tong ◽  
Zhangjian Zhou
Keyword(s):  
Mechanical Properties ◽  
Zr Addition ◽  
Microstructure And Mechanical Properties ◽  
Ods Steels
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