Paper Title:
Investigation of the Development Processes of Self-Organizing, Protective Oxide Scales and Wear Resistant Surface Layers on the Fe-44%Cr-1%Ni-4%Al-0.3%La Alloy
  Abstract

Using the methods of scanning electron microscopy (SEM), Auger electron spectrometry (AES), fast electron diffraction (FED) in the “on reflection” regime and wavelength dispersive spectrometry (WDS) a complex investigation of the hierarchical sequence of amorphous Beilby layer formation has been studied due to the self-organizing dissipative processes, associated with extensive cold work, on the surface of an Fe-Cr-Ni-Al-La alloy, with high (>40%) chromium content. It was established that, the surface layer (≤1μm thickness) of the mechanically polished specimen of Fe-44%Cr-1%Ni-4%Al-0.3%La alloy consists of the amorphous Beilby layer and that its adjacent matrix layer, crushed due to the plastic deformation, formed an entropy “excited” functional system, which at the temperature of 1200°C in laboratory atmosphere permits the formation of an oxide surface layer with a micro-wrinkles modulated structure of uniform thickness, in the form of mixture of nanocrystallites (100÷500nm) made of oxides of atoms constituting the basic metallic matrix. Beneath this layer a thin alumina scale is observed to form. Increasing the oxidation temperature causes the regrowth of nanocrystallites and also the recrystallization processes, accompanied by solid-phase reactions between oxide nano-particles. This leads to scale delamination at the superficial oxide thin uniform alumina layer interface. The Al2O3 layer is characterized by high adherence with metallic substrate and provides protective features against both high temperature (1200°C) oxidation of the matrix and resistance to abrasion. By the pretreatment at 1200°C of the investigated alloy’s surface modified specimens, there forms a low thickness (several microns) scale which has ultra fine graininess (~1μ) with no porosity and blocked grain boundaries short-circuit diffusion paths. This gives to the scale the ability to protect the metallic matrix against high temperature gas (and other aggressive environment) corrosion.

  Info
Periodical
Materials Science Forum (Volumes 595-598)
Edited by
Pierre Steinmetz, Ian G. Wright, Alain Galerie, Daniel Monceau and Stéphane Mathieu
Pages
833-840
DOI
10.4028/www.scientific.net/MSF.595-598.833
Citation
O. Tsurtsumia, E. Kutelia, B. Bulia, O. Mikadze, "Investigation of the Development Processes of Self-Organizing, Protective Oxide Scales and Wear Resistant Surface Layers on the Fe-44%Cr-1%Ni-4%Al-0.3%La Alloy", Materials Science Forum, Vols. 595-598, pp. 833-840, 2008
Online since
September 2008
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Rabindra Mahapatra, A.W. Davis
Abstract:In this paper we report the oxidation behavior of Rh-xTi (x = 15 & 20 atomic percent) alloys isothermally exposed in air between 1000 and...
721
Authors: Xiao Fei Ding, Yi Tan, Yong Shen, Fu Gang Wang, Jenn Ming Yang
Abstract:Three types of Ti-Al-Nb ternary alloys are obtained by arc-melting and heat treatment, which are γ-TiAl single phase alloy, γ-TiAl + α2-Ti3Al...
403
Authors: Shi Yu Qu, Ya Fang Han, Jin Xia Song, Yong Wang Kang
Abstract:The effects of Cr and Al on high temperature oxidation resistance of Nb-Si system intermetallics have been investigated by scanning electron...
1485
Authors: Antonio Forn, Isabel Espinosa, Maite T. Baile, Elisa Rupérez
Abstract:Semi solid processing reduces porosity and amount of trapped gas and it allows heat treatment T6 that improves a hard anodized oxide layer....
755
Authors: Xu Dong Lu, Ce An Guo, Jie Wang, Shu Wu Ma
Chapter 1: Metal Materials
Abstract:The cyclic oxidation behaviour of Ni 5.5Al 2.6Ti 4.8Co 3.9Mo 5.0W 11.0Cr superalloy at 900 °C in air has been investigated by means of...
51