scholarly journals Effect of Niobium Addition on the High-Temperature Oxidation Behavior of 22Cr25NiWCoCu Stainless Steel in Air

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 975
Author(s):  
Sheng-Yao Huang ◽  
Wen-Ta Tsai ◽  
Yeong-Tsuen Pan ◽  
Jui-Chao Kuo ◽  
Hsien-Wei Chen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Oxidation Behavior ◽  
Volume Fraction ◽  
Average Particle Size ◽  
Grazing Incidence ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior ◽  
Nb Addition

The oxidation behavior of 22Cr25NiWCoCu stainless steel with 0–0.86 wt.% Nb addition was investigated at 900 °C in air. With an increase in Nb addition, the volume fraction and average particle size of Nb (C, N) increased, but the grain size decreased. The results of grazing incidence X-ray diffraction indicated that the steels with Nb additions promoted Cr2O3 formation. After 10–100 h of oxidation, Cr depletion occurred at the region with Nb (C, N) precipitates because of its high Cr consumption rate, leading to Fe oxide generation. Finally, after 100 h of oxidation, the outer layer of Fe2O3 and the inner layer of (Cr, Fe, Mn)3O4 were formed.

Effect of Compressive Stress on the High-Temperature Oxidation Behavior of a Fe-20Ni Alloy in Air

2018 ◽  
Vol 921 ◽  
pp. 168-176
Author(s):  
Chang Hai Zhou ◽  
Rui Yun Pan ◽  
Hai Tao Ma
Keyword(s):  
Compressive Stress ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Oxide Scales ◽  
External Scale ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
Kinetics Of

The oxidation behavior of Fe-20Ni alloy under compressive stress in air was studied at 800, 900 °C. The results examined by using scanning electron microscope (SEM) and X-ray diffraction (XRD) indicates that the oxide scales were consisted of an external scale and a subscale which has an intragranular scale (above 5 h at 800 °C and 900 °C) and an intergranular scale. Compared with the unstressed specimen, the growth kinetics of external scale was accelerated by an applied compressive stress. Besides, the compressive stress induced an increase in the growths of intragranular scale and intergranular scale formed on the specimens oxidized at 900 °C. However, the effect of compressive stress on the growth of intergranular scale and intragranular scale was not obvious in the case of 800°C. In addition, cracks developed in the subscale for the specimens oxidized under 2.5 MPa compressive stress when the oxidation time exceeded 20 h.

Al2O3-Water Nanofluids for Heat Transfer Application

MRS Advances ◽  
2019 ◽  
Vol 4 (28-29) ◽  
pp. 1611-1619 ◽  
Author(s):  
Lakshita Phor ◽  
Tanuj Kumar ◽  
Monika Saini ◽  
Vinod Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Load ◽  
Volume Fraction ◽  
Average Particle Size ◽  
Power Input ◽  
Experimental Investigations ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
External Power

AbstractThis manuscript aims at synthesizing Al2O3-de-ionized water nanofluid and constructing a practical design of self-cooling device that does not require any external power input. Crystalline phase of powder was confirmed by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) showed the various functional groups and absorption bands and average particle size was calculated to be 58.608 nm by Field Emission Scanning Electron Microscopy (FESEM) annealed at 900K. Experimental investigations were carried out to determine the effect of volume fraction of Al2O3 nanoparticles in the nanofluid on the rate of heat transfer from heat load to heat sink. Temperature of heat load was taken as 80° C. According to our results, cooling by 15°C, 13°C and 12°C was attained when volume fraction of nanoparticles was 1.5%, 1% and 0.5% respectively. The thermal conductivity was also measured and found to be increasing with the concentration of nanoparticles in nanofluid. Hence, indicating the use of nanofluids with suitable concentration in various cooling applications.

scholarly journals High Temperature Anti-Oxidation Behavior and Mechanical Property of Radio Frequency Magnetron Sputtered Cr Coating

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1509
Author(s):  
Guangbin Li ◽  
Yanhong Liu ◽  
Yingchun Zhang ◽  
Huailin Li ◽  
Xiaojing Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Radio Frequency ◽  
Oxidation Behavior ◽  
Zirconium Alloys ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
High Temperature Steam ◽  
High Temperature Oxidation Behavior ◽  
Cr Coating

A dense and uniform Cr coating was fabricated on the zirconium alloys fuel claddings by radio frequency (RF) magnetron sputtering to improve the mechanical and anti-oxidation properties under 1200 °C steam environment. The phase composition and the micro and macro morphologies of the specimens were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscope (SEM) and optical-microtopography (OM) analyses, and the high-temperature oxidation behavior was evaluated at 1200 °C steam environment for 3000 s. In this paper, there exists a positive correlation between thickness and Vickers hardness (HV), and a negative correlation between surface roughness and bonding force. Radial tensile was introduced to investigate the deformation-resistant performance, and the displacement of the Cr-coated specimen was as low as 2.32 mm, which was much lower than the uncoated zircaloy cladding (3.05 mm). Different thicknesses of Cr coatings were deposited to investigate the oxidation degrees of zircaloy cladding under a high-temperature steam environment. The optimal 6 μm Cr-coated zirconium alloys cladding exhibited an excellent anti-oxidation property, and the weight gain was as low as ~4.12 mg/cm2, which was almost one-third of the uncoated specimen.

High Temperature Oxidation Behavior of Arc-sprayed FeCrBAlMo Coating

2016 ◽  
Vol 19 (1) ◽  
Author(s):  
Xin Zhang ◽  
Zehua Wang ◽  
Jinran Lin
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Steel Substrate ◽  
Arc Spraying ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Velocity Arc Spraying ◽  
High Temperature Oxidation Behavior

AbstractFeCrBAlMo coating was deposited on an AISI 20 steel substrate by high velocity arc spraying (HVAS). Compared with FeCrBSiMo coating and pristine AISI 20 steel, the microstructure and high temperature oxidation behavior of FeCrBAlMo coating were investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Meanwhile, the bonding strength of the coatings was also measured. The results indicated that both coatings were composed of α(Fe,Cr) and Fe

Investigating the High Temperature Oxidation Behavior of TiAl-Based Alloys with Nickel and Ruthenium Additions

2014 ◽  
Vol 1019 ◽  
pp. 294-301
Author(s):  
H.C. Mantyi ◽  
L.A. Cornish ◽  
Lesley H. Chown ◽  
I. Alain Mwamba
Keyword(s):  
Room Temperature ◽  
Oxidation Behavior ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
Titanium Aluminium

Pure powders of titanium, aluminium, nickel and ruthenium were mechanically alloyed and melted in a button arc furnace under an argon atmosphere to produce two alloys of composition Ti-52.5Al-10.0Ni (at.%) and Ti-52.5Al-10.0Ni-0.2Ru (at.%). The alloys were then cut and metallographically prepared. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to characterize the samples. Thermogravimetric analysis (TGA) was used to analyze the oxidation behavior from room temperature up to 1050°C. The alloys were also oxidized in air at 1050°C for 120 hours. The Ti-52.5Al-10.0Ni (at.%) alloy formed dendrites of γ-TiAl (55.6 at.% Al) surrounded by a eutectic of γ-TiAl + Al3NiTi2 (τ3) phases. The Ti-52.5Al-10.0Ni-0.2Ru (at.%) alloy formed dendrites of γ-TiAl (53.6 at.% Al) surrounded by a eutectic of γ-TiAl + Al3NiTi2 (τ3). The ruthenium was mostly in solid solution (0.3 at.%) in the Al3NiTi2 (τ3) phase, although traces of it were present in the dendrites (0.1 at.% Ru). When oxidized in air from room temperature to 1050°C, the as-cast Ti-52.5Al-10.0Ni-0.2Ru (at.%) had a mass gain of 0.60% and the as-cast Ti-52.5Al-10.0Ni (at.%) had a mass gain of 0.97%. Isothermal oxidation of both alloys at 1050°C for 120 hours formed mixed metal oxides of TiO2+Al2O3 on the surface.

High Temperature Oxidation Behavior of APM and APMT under Dry Air/Steam Condition

MRS Advances ◽  
2016 ◽  
Vol 1 (35) ◽  
pp. 2471-2476 ◽  
Author(s):  
KkochNim Oh ◽  
KwangSup Eom ◽  
Zhiyuan Liang ◽  
Preet M. Singh
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Fuel Cladding ◽  
Temperature Oxidation ◽  
Dry Air ◽  
High Temperature Oxidation Behavior

ABSTRACTOxidation behavior of alumina forming ferritic stainless steel (FeCrAl type stainless steels) grades APM and APMT, which are candidate alloys for fuel cladding, was studied using thermogravimetric analysis under dry air condition, and compared to that of ZIRLO®. In addition to the dry air condition, we also studied the high temperature oxidation behavior of APM and APMT under 100% steam condition in order to compare the effect of environment on the oxidation behavior of these alloys. APM and APMT showed an excellent oxidation resistance at high temperatures compared to ZIRLO® under dry air condition due to a stable Al2O3 oxide scale formed at the surface. Under steam condition, the oxidation rate of APM and APMT was found to be higher compared to that under the dry air condition.

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