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.

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.

Effect of WС Content on the Mechanical Properties and High Temperature Oxidation Behavior of Ti(С,N)-Based Cermets

2018 ◽  
Vol 274 ◽  
pp. 9-19
Author(s):  
Guo Tao Zhang ◽  
Yong Zheng ◽  
Yi Jie Zhao ◽  
Wei Zhou ◽  
Jia Jie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
Oxide Scales ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxidation Rates ◽  
High Temperature Oxidation Behavior

Ti (C,N)-based cermets with varying WC additions (Ti (C0.6N0.4)-36Ni-12Mo-1C-xWC, x = 0, 3, 6 and 9 wt%) were prepared by conventional powder metallurgy techniques. The microstructure and mechanical properties of all four Ti (C,N)-based cermets were investigated. Isothermal oxidation of all four cermets were also investigated in air at 800°C up to 100 h using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD). The grains of Ti (C,N)-based cermets became more homogeneous with the increase of WC content. The TRS and fracture toughness increased with the increase of WC content and then decreased when WC content exceeded 6wt%, but hardness decreased continuously with the increase of WC content. The oxide scales formed on the surface of all four samples during the oxidation process were porous and multi-layered, consisting of NiO outerlayer and TiO2 based innerlayer, respectively. The thickness of the oxide scales and oxidation rates increased with the increase of WC content, especially when the content of WC addition reached 9wt%. The cermet with 6wt% WC addition showed excellent mechanical properties and acceptable high temperature oxidation resistance.

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.

Performance of Fe-33Ni-18Cr Alloy at High Temperature Oxidation

2020 ◽  
Vol 1010 ◽  
pp. 65-70
Author(s):  
Zahraa Zulnuraini ◽  
Noraziana Parimin
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Thick Layer ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxide Particles ◽  
Lower Temperature

This paper investigates the performance of Fe-33Ni-18Cr alloy at high temperature oxidation. The samples were isothermally oxidized at three different oxidation temperatures, namely, 600 °C, 800 °C and 1000 °C for 150 hours. This alloy was ground by using several grits of SiC paper as well as weighed by using analytical balance and measured by using Vernier caliper before oxidation test. The characterization was carried out using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) and x-ray diffraction (XRD). The results show that, the higher oxidation temperatures, the weight gain of the samples were increase. Sample of 1000 °C indicate more weight gain compared to samples oxidized at 600 °C and 800 °C. The kinetic of oxidation of all samples followed the parabolic rate law. The surface morphology of oxide scale at lower temperature is thin and form a continuous layer, while at high temperature, the oxide scale develops thick layer with angular oxide particles.

Microstructural Evolution during High-Temperature Oxidation of Ti2AlN Ceramics

2010 ◽  
Vol 65 ◽  
pp. 106-111
Author(s):  
Bai Cui ◽  
Rafael Sa ◽  
Daniel Doni Jayaseelan ◽  
Fawad Inam ◽  
Michael J. Reece ◽  
...  
Keyword(s):  
High Temperature ◽  
Microstructural Evolution ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxidation In Air ◽  
Α Al2o3 ◽  
Increasing Temperature

Microstructural evolution of Ti2AlN ceramics during high-temperature oxidation in air has been revealed by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEGSEM), and energy-dispersive spectroscopy (EDS). After oxidation below 1200 °C, layered microstructures formed on Ti2AlN surfaces containing anatase, rutile, and α-Al2O3. Above 1200 °C, more complex layered microstructures formed containing Al2TiO5, rutile, α-Al2O3, and continuous void layers. With increasing temperature, anatase gradually transformed to rutile, and TiO2 reacted with α-Al2O3 to form Al2TiO5. Based on these microstructural observations, an oxidation mechanism for Ti2AlN ceramics is proposed.

Microstructure and High-Temperature Oxidation of Ni-Si3N4 Composite Coatings by Pulse Electrodeposition

2015 ◽  
Vol 817 ◽  
pp. 421-425
Author(s):  
Kun Zhao ◽  
Wan Chang Sun ◽  
Chun Yu Miao ◽  
Hui Cai ◽  
Ju Mei Zhang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Electro Deposition ◽  
X Ray ◽  
Crystallite Structure

Nickel matrix and Si3N4 micron particles were co-deposited on the aluminum alloy by pulse electro-deposition for high temperature performance. Meanwhile, the oxidation resistance was evaluated through the high temperature oxidation test. The phase structure, micrographs and components of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS) respectively. The results indicated that Si3N4 particles were uniformly distributed across the coating and there were no pores and cracks or other defects at the coating/substrate interface. Ni-Si3N4 composite coatings are characterized by pyramidal micro-crystallite structure. The thickness of Ni-Si3N4 composite coatings were up to 80 μm for 2h. The results also revealed that the Ni-Si3N4 composite coatings presented better oxidation resistance than the pure Ni coating and aluminum alloy at high temperature. After oxidation at 673 K for 8h, the oxidation resistance of Ni-Si3N4 composite coatings presented the improved oxidation resistance behavior compared to pure Ni and the aluminum alloy, respectively.

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