High Temperature Corrosion of Fe-30Cr in Flowing CO2 Gas

2012 ◽  
Vol 501 ◽  
pp. 165-168
Author(s):  
S. Nurul Atikah ◽  
Norinsan Kamil Othman ◽  
Azman Jalar
Keyword(s):  
High Temperature ◽  
Visual Inspection ◽  
Optical Microscope ◽  
High Temperature Corrosion ◽  
Significant Weight Loss ◽  
X Ray Diffraction ◽  
Co2 Gas ◽  
X Ray ◽  
Change Measurement ◽  
Microstructure Observation

A plate of Fe-30Cr (wt%) were subjected to isothermal furnace at 600 °C in flowing CO2 gas at total pressure of approximately 1 atm. The reacted samples morphology and microstructure were characterized by using visual inspection, optical microscope, SEM and EDAX. The weight change measurement showed a fluctuating result during the exposure. The significant weight loss was observed after five hours exposure due to oxide scale exfoliation. Formation of different oxide and element presents on the interface of the specimen such as Cr2O3, C and Fe3C were revealed by X-ray diffraction and with supported by EDAX analysis. This behavior of the high temperature corrosion on Fe-30Cr was discussed based on morphology and microstructure observation.

High temperature corrosion behaviour of aluminised FC 25 cast iron using pack cementation

2019 ◽  
Vol 66 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Somrerk Chandra-Ambhorn ◽  
Neramit Krasaelom ◽  
Tummaporn Thublaor ◽  
Sirichai Leelachao
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Corrosion Behaviour ◽  
Mass Gain ◽  
High Temperature Corrosion ◽  
Pack Cementation ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Seat Insert

Purpose This study aims to apply the pack cementation to develop the Fe-Al layers on the surface of FC 25 cast iron in order to increase the high-temperature corrosion resistance of the alloy. Design/methodology/approach Pack cementation was applied on the surface of FC 25 cast iron at 1,050°C. The bare and aluminised alloys were subjected to the oxidation test in 20 per cent O2-N2 at 850 °C. Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used for characterisation. Findings The layers of pack cementation consisted of Fe2Al5, FeAl2 and FeAl, and solid solution alloyed with Al. The oxidation kinetics of the bare cast iron was parabolic. Mass gain of the aluminised cast iron was significantly decreased compared with that of the bare cast iron. This was because of the protective alumina formation on the aluminised alloy surface. Al in the Fe–Al layer also tended to be homogenised during oxidation. Originality/value Even though the aluminising of alloys was extensively studied, the application of that process to the FC 25 cast iron grade was originally developed in this work. The significantly reduced mass gain of the aluminised FC 25 cast iron makes the studied alloy be promising for the use as a valve seat insert in an agricultural single-cylinder four-stroke engine, which might be run by using a relatively cheaper fuel, i.e. LPG, but as a consequence requires the higher oxidation resistance of the engine parts.

INVESTIGATION ON HIGH-TEMPERATURE CORROSION BEHAVIOR OF INCONEL 600 UNDER SO2-BEARING GAS AT 650°C

2019 ◽  
Vol 27 (06) ◽  
pp. 1950155
Author(s):  
KWANG-HU JUNG ◽  
SEONG-JONG KIM
Keyword(s):  
Electron Microscope ◽  
Weight Gain ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
High Temperature Corrosion ◽  
X Ray Diffraction ◽  
Oxide Structure ◽  
X Ray ◽  
Inconel 600 ◽  
Scanning Electron

The corrosion characteristics of Inconel 600 were investigated at 650∘C in air and 76%[Formula: see text]%[Formula: see text]%[Formula: see text]%SO2 gas environment up to 500[Formula: see text]h. Specimens exposed to each condition were characterized by weight gain, scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction. The oxide structure consisting of the thin Cr2O3 layer and Cr2O3 nodules was observed, which increased the weight gain of specimens. In the SO2-bearing gas, it showed a bigger weight gain due to the coarsening of Cr2O3 nodules. Therefore, it was suggested that the sulfur-accelerated coarsening of Cr2O3 nodules at the high temperature.

scholarly journals Effect of CNT Contents on the Microstructure and Properties of CNT/TiMg Composites

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1620
Author(s):  
Xiaomin Yuan ◽  
Haonan Zhu ◽  
Huiling Ji ◽  
Yiwei Zhang
Keyword(s):  
Cross Section ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Observation ◽  
The Matrix ◽  
Scanning Electron

Carbon nanotubes (CNTs), dispersed in absolute ethanol, were evenly mixed into Ti/MgH2 powders by wet milling. Then, we applied the vacuum hot-pressed sinteringmethod to the CNTs/TiMg composite materials. An optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and a field emission scanning electron microscope (FESEM) were used for the microstructure observation and phase analysis of samples. The mechanical properties were measured via the micro-vickers hardness. The results show that the main phases in the composites were Ti, Mg and C. Meanwhile, a small amount of Ti-Mg solid solution phase was also found. The cross-section morphology of the composites shows that the melted magnesium fills the grain interface during extrusion and that the composites have a better compactness.The microstructures of the composites have been greatly refined as the CNT contents increased. The structure of the composites was further refined when 0.5 wt.% CNTs were added. The fracture surface is obviously a ductile fracture. The microhardness increases obviously with the CNT content increasing. When the content of the CNTs is 1.0 wt.%, the microhardness of the composites reaches 232 HV, which is 24% higher than that of the matrix.

High-Temperature Corrosion of Copper Induced by TeO2

CORROSION ◽  
10.5006/3295 ◽  
2020 ◽  
Vol 76 (2) ◽  
pp. 210-216
Author(s):  
Anton Klimashin
Keyword(s):  
High Temperature ◽  
Phase Distribution ◽  
Copper Ion ◽  
High Temperature Corrosion ◽  
Corrosion Layer ◽  
Corrosion Process ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Melt

It was found that copper is susceptible to the accelerated high-temperature corrosion induced by TeO2 at 650°C in air, which occurs at a constant rate. The calculated corrosion rate constant is 4.5 × 10−4 kg·m−2·s−1 and does not depend on the specific mass of tellurium oxide. Based on the results of the analysis of the microstructure (scanning electron microscopy/energy dispersive x-ray spectroscopy) and the phase composition (x-ray diffraction) of two formed corrosion layers, the phase distribution in the corrosion product has been ascertained. It was shown that during the corrosion process at 650°С, the inner corrosion layer containing Cu2O and Cu2Te and the outer corrosion layer mainly containing CuTe2O5 and Cu2O were formed. The inner layer provides a high copper ion conductivity due to Cu2Te, while the outer layer possesses a high oxygen ion conductivity due to the oxide melt. The mechanism of the overall corrosion process has been proposed.

High Temperature Corrosion Kinetics using a Fast X-Ray Diffraction Method

1991 ◽  
Vol 79-82 ◽  
pp. 617-622
Author(s):  
Vladislav Kolarik ◽  
Maria Juez-Lorenzo ◽  
N. Eisenreich ◽  
W. Engel
Keyword(s):  
High Temperature ◽  
Diffraction Method ◽  
High Temperature Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Corrosion Kinetics

Failure Analysis of Burner Muffle in Shell Gasifier

2014 ◽  
Author(s):  
Wen Liu ◽  
Jin Shi ◽  
Qiuping Chen ◽  
Guoshan Xie ◽  
Yufeng Zhou ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Failure Analysis ◽  
Structural Study ◽  
Cooling Water ◽  
Optical Microscope ◽  
Current Work ◽  
Economic Losses ◽  
X Ray Diffraction ◽  
X Ray

The failure of burner muffles in shell gasifiers has been a common problem, which directly leads to unexpected shutdown in operation of the gasifier and huge economic losses for the factory. Therefore, the experiment of the failure analysis to the burner muffle was conducted in the current work. The microstructure of the burner muffle after failure was measured by means of optical microscope, SEM (scanning electro-microscope) and X-ray diffraction. The reason of failure was obtained based on the analysis of experimental data together with the structural study of the gasifier. It is indicated that the failure of burner muffle is accounted for slag overflow and “backfire”, which lead to local temperature increasing. Cooling water tubes of Burner muffle were partially melted due to oxidation and sulphidation at high temperature, resulting into water leaks.

Materials Development and Hardness Properties of Aluminum Alloy

2014 ◽  
Vol 575 ◽  
pp. 83-87
Author(s):  
Muhammad Husna Al Hasa ◽  
Masrukan ◽  
Arief Sasongko Adhi
Keyword(s):  
Aluminum Alloy ◽  
Rolling Process ◽  
Optical Microscope ◽  
Nuclear Industry ◽  
X Ray Diffraction ◽  
Alloy Plate ◽  
X Ray ◽  
Hardness Tester ◽  
Microstructure Observation ◽  
Rolling Deformation

This research aims to develop an aluminum alloy suitable for applications in the nuclear industry, particularly in terms of its hardness. A synthesized AlFeNiMg alloy plate was subjected to deformation in a gradual rolling process at room temperature. A Vickers hardness tester and an optical microscope were employed to analyze the hardness and to observe the microstructure of the aluminum alloy consecutively. Analyses of elements and phase structures were performed by EDS-SEM and X-ray diffraction. The result shows that the hardness of AlFeNiMg alloy increases along with the increase in rolling deformation. The alloy hardness increases from 88 HV to 113 HV, 135 HV, 153 HV and 165 HV at percent cold reduction of 30%, 53%, 65% and 88% consecutively. From the microstructure observation, the grains tend to get more elongated along with increasing rolling deformation. The pattern analysis of X-ray diffraction shows that there are two phases, namely α and θ (FeAl3).

scholarly journals In-situ study of high temperature corrosion kinetics of iron using a fast X-ray diffraction method

1993 ◽  
Vol 03 (C9) ◽  
pp. C9-461-C9-467 ◽  
Author(s):  
M. Juez-Lorenzo ◽  
V. Kolarik ◽  
N. Eisenreich ◽  
W. Engel ◽  
A. J. Criado
Keyword(s):  
High Temperature ◽  
Diffraction Method ◽  
High Temperature Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Study ◽  
Corrosion Kinetics ◽  
Kinetics Of
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