Relation between impurities and oxide-scale growth mechanisms on Ni-34Cr and Ni-20Cr alloys. I. Influence of C, Mn, and Si

1990 ◽  
Vol 33 (3-4) ◽  
pp. 191-235 ◽  
Author(s):  
G. Ben Abderrazik ◽  
G. Moulin ◽  
A. M. Huntz
Keyword(s):  
Oxide Scale ◽  
Growth Mechanisms ◽  
Scale Growth

Relation between impurities and oxide-scale growth mechanisms on Ni-34Cr and Ni-20Cr alloys. II. Influence of sulphur

1990 ◽  
Vol 33 (3-4) ◽  
pp. 237-264 ◽  
Author(s):  
G. Ben Abderrazik ◽  
G. Moulin ◽  
A. M. Huntz
Keyword(s):  
Oxide Scale ◽  
Growth Mechanisms ◽  
Scale Growth

Assessment of a Mechanical Model Associated with Oxide Scale Growth on T91 Steel at 550 °C Under Wet Atmosphere

2017 ◽  
Vol 88 (1-2) ◽  
pp. 57-70 ◽  
Author(s):  
Marie-Christine Demizieux ◽  
Jérôme Favergeon ◽  
Laure Martinelli ◽  
Clara Desgranges ◽  
Gaël Sattonnay
Keyword(s):  
Oxide Scale ◽  
Mechanical Model ◽  
Scale Growth

On the Estimation of Oxide Scale Growth in T22 Superheater and Reheater Tubes

2012 ◽  
Vol 516-517 ◽  
pp. 364-369
Author(s):  
Cai Xia Bian ◽  
Ke Yi Zhou ◽  
Jian Qun Xu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Oxide Scale ◽  
Growth Kinetics ◽  
Iterative Procedure ◽  
Heat Transfer Analysis ◽  
Oxide Growth ◽  
Scale Growth ◽  
Small Influence ◽  
Influence Degree

In this paper, an iterative procedure was performed for the prediction of scale growth in T22 superheater and reheater tubes, which utilized empirical formulae for oxide-growth kinetics in steam and heat transfer analysis. Several expressions for oxide-growth kinetics and different thermal conductivities of scale were considered in calculations. The results indicate that the expression for oxide-growth kinetics can affect the estimated results significantly, and the thermal conductivity of scale has relatively small influence on the prediction of scale growth, but the influence degree increases with time.

High Temperature Oxidation of Fe-9Cr-1Mo Steel in Liquid Metal

2008 ◽  
Vol 595-598 ◽  
pp. 519-528 ◽  
Author(s):  
Laure Martinelli ◽  
Fanny Balbaud-Célérier ◽  
Gerard Picard ◽  
Gerard Santarini
Keyword(s):  
Oxide Scale ◽  
Oxidation Kinetics ◽  
Oxidation Mechanism ◽  
Lattice Diffusion ◽  
Experimental Results ◽  
Liquid Lead ◽  
Regulation Mechanism ◽  
Scale Growth ◽  
Temperature Oxidation ◽  
Steel Oxidation

The oxidation mechanism of the T91 martensitic steel in oxygen-saturated Pb-Bi eutectic at 470°C has been investigated to develop a long term predictive model of the steel oxidation kinetic. This work is performed in the frame of life duration studies carried out for the MEGAPIE spallation module demonstrator dedicated to the feasibility demonstration of an hybrid reactor. Our scientific approach has been based on an experimental characterization of the oxide scales and of the T91 steel oxidation kinetics. From these experimental results, an oxidation mechanism has been elaborated and then simulated. The oxide scale formed at the T91 surface has a duplex structure, constituted of an external magnetite scale and an internal Fe-Cr spinel scale. A scale growth mechanism has been proposed: the magnetite scale growth seems to be limited by the iron lattice diffusion inside the duplex oxide scale. At the same time, a self-regulation mechanism seems to govern the Fe-Cr spinel scale growth. This mechanism consists of a non-limiting oxygen diffusion step, which is carried out, across the oxide scale, inside liquid lead nano-channels and a limiting iron oxide lattice diffusion step. Considering the proposed oxidation mechanism, a simulation of the growth of the two oxides scales has been carried out and compared to the experimental oxidation kinetics. The excellent agreement between the experimental results and the simulations supports to accept the proposed mechanism, leading to prediction of kinetics for long oxidation durations.

Microstructural development of protective A12O3 scales

1984 ◽  
Vol 42 ◽  
pp. 594-597
Author(s):  
James L. Smialek
Keyword(s):  
Boundary Diffusion ◽  
Short Circuit ◽  
Microstructural Development ◽  
Growth Mechanisms ◽  
Scale Growth ◽  
Coating Materials ◽  
Turbine Engine ◽  
Active Elements ◽  
Slow Growing ◽  
Nicral Alloys

The most severe demands of a jet turbine engine in terms of high temperature (1000-1100°C) oxidation of superalloys have been successfully met with the use of NiCrAlY or NiAl types of coating materials. The success of these coatings is due to their ability to form an adherent slow-growing scale of α-Al2O3. The growth mechanism of these scales is generally accepted to be short-circuit grain boundary diffusion of oxygen resulting in an inward growing scale. Oxide-metal adherence is ultimately due to a fine dispersion of oxygen active elements (Y, Zr, Hf, Th, etc.) in the coating, whose effect appears to be intricately involved with subtle changes in scale growth processes. The present paper documents the scale microstructures developed on NiCrAl alloys, and emphasizes features relevant to growth mechanisms.

Determination of correlation functions of the oxide scale growth and the temperature increase

2011 ◽  
Vol 18 (8) ◽  
pp. 2260-2271 ◽  
Author(s):  
B.H. Salman ◽  
M.Z. Hamzah ◽  
J. Purbolaksono ◽  
J.I. Inayat-Hussain ◽  
H.A. Mohammed ◽  
...  
Keyword(s):  
Oxide Scale ◽  
Correlation Functions ◽  
Temperature Increase ◽  
Scale Growth
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