scholarly journals High-Temperature Oxidation Behavior and Kinetics of Forged 12Cr-MoVW Steel

2017 ◽  
Vol 62 (2) ◽  
pp. 1099-1104
Author(s):  
Yong Hwan Kim ◽  
Jeong-Jung Oak ◽  
Ki-Chang Bae ◽  
Wook Jin Lee ◽  
Yong Ho Park
Keyword(s):  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
X Ray Diffraction ◽  
Protective Oxide ◽  
Cross Sectional ◽  
Temperature Oxidation ◽  
Protective Oxide Layer ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
Kinetics Of

AbstractThe oxidation kinetics of forged 12Cr-MoVW steel was investigated in an air (N2+O2) atmosphere at 873-1073 K (Δ50 K) using thermogravimetric analysis. The oxidized samples were characterized using X-ray diffraction, and the surface and cross-sectional morphologies were examined using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The forged 12Cr-MoVW steel samples exhibited parabolic behavior and a low oxidation rate compared with their as-cast counterparts. A protective oxide layer was uniformly formed at relatively low temperature (≤973 K) for the forged samples, which thus exhibited better oxidation resistance than the as-cast ones. These oxides are considered solid-solution compounds such as (Fe, Cr)2O3.

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.

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

High Temperature Oxidation Behavior of ZrB2-SiC-Graphite Composite Heated by High Electric Current

2010 ◽  
Vol 105-106 ◽  
pp. 162-164
Author(s):  
Hong Bo Chen ◽  
Song He Meng
Keyword(s):  
High Temperature ◽  
Electric Current ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Graphite Composite ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
Oxidation Testing

High temperature oxidation testing was carried out on hot-pressed ZrB2-SiC-graphite composite by using high electric current heating. The composites oxidation behavior was investigated, the temperature of oxidized specimens was above 2000°C. The results found that the UHTC composite was ruptured at oxidized temperature 2055°C. The microstructure of surface and cross-section of posttest samples were investigated by scanning electron microscopy along with energy and X-ray diffraction. The failure mechanism of rupture was also discussed.

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.

Research on the Si-Ti High Temperature Oxidation-Resistant Coatings for Tantalum Alloys

2013 ◽  
Vol 785-786 ◽  
pp. 45-51
Author(s):  
Pei Pei Song ◽  
Jun Le ◽  
Feng Ye ◽  
Xiao Cheng Sheng ◽  
Xiao Wei Zhang
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Temperature Oxidation ◽  
X Ray ◽  
Different Temperatures ◽  
Slurry Method ◽  
Sectional Structure

Si-Ti coatings were prepared on the surface of T-222 alloy by fused slurry method at different temperatures (1425-1500°C). Microstructure and composition of the coatings were characterized and analysed through scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), energy dispersive X-ray spectrometry (EDS) respectively. The coating fabricated at 1450°C exhibited excellent structure compatible with high temperature oxidation resistance. Its surface is relatively smooth with few holes and cracks and the main phase on the surface is (Ti, Ta)Si that possesses outstanding corrosion resistance. Moreover, the cross-sectional structure of the coating is smooth and compact which can effectively prevent O2 from permeation. The isothermal oxidation behaviors in pure O2 atmosphere at 1500°C for 2h finally demonstrate that the optimum coating temperature is 1450°C.

High-temperature oxidation behavior of arc ion plated NiCoCrAlYSiB coatings on cobalt-based superalloy

2006 ◽  
Vol 21 (3) ◽  
pp. 737-746 ◽  
Author(s):  
Y.J. Tang ◽  
Q.M. Wang ◽  
F.H. Yuan ◽  
J. Gong ◽  
C. Sun
Keyword(s):  
Cross Sections ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Alloy Element ◽  
Oxide Scales ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Ion Plating ◽  
Aluminide Coatings ◽  
High Temperature Oxidation Behavior

NiCoCrAlYSiB coatings were deposited on the Co-based superalloy K40 by arc ion plating (AIP). The oxidation behavior of the bare alloy and of the coated specimens was tested in static air for 200 h at 1000 °C and 100 h at 1050 °C. The results showed that the oxidation rate of the system was greatly reduced by the addition of the NiCoCrAlYSiB coatings. Thin and adherent α–Al2O3 scales that formed on the coated specimens protected the substrates from further oxidation attack while non-protective oxide scales, mainly of Cr2O3 and CoCr2O4, appeared on bare K40 alloy. Element profiles on metallographic cross sections indicated that apparent interdiffusion occurred between the coatings and the substrates. The interdiffusion behavior and the resulting microstructure were investigated. As compared to aluminide coatings, NiCoCrAlYSiB coatings have less influence on the substrate microstructure.

High-Temperature Oxidation Behavior and Formation Mechanism of Rolling Cracks of Fe-36Ni Invar Alloy

2013 ◽  
Vol 32 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Yan-chong Yu ◽  
Wei-qing Chen ◽  
Hong-guang Zheng
Keyword(s):  
High Temperature Oxidation ◽  
Short Circuit ◽  
Invar Alloy ◽  
External Scale ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Diffusion Paths ◽  
High Temperature Oxidation Behavior ◽  
Short Circuit Diffusion

AbstractThe oxidation of Fe-36Ni invar alloy in 5%O2-15%CO2-80%N2 atmosphere at 1200 °C for 4 h and the cause of rolling cracks have been investigated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Gleeble thermal simulation machine. The result showed that the scales consisted of the external scale and the subscale. The external scale had stratified structures of Fe2O3/Fe3O4 + NiO/Fe3O4 + FeO + NiO from outside to inside. The subscale had a typical substructure of the intra-granular subscale and the inter-granular subscale. Oxidation particles of (Fe3O4 + FeO) were isolated in FeNi3 matrix in the intra-granular subscale zone. The grain boundary was the preferential short-circuit diffusion paths of the diffusing O and was first to be oxidized. The inter-granular subscale led to the subscale and was the origin of rolling cracks. The protective heating measure was put forward to prevent rolling cracks.

Sign in / Sign up

Export Citation Format

Share Document