Affiliation:
1. National Technical University of Athens
2. CNRS Nancy Université UPV Metz
Abstract
Superaustenitic stainless steels exhibit excellent corrosion resistance, at a wide variety of exposure temperatures, especially in chloride containing environments, coupled with desirable mechanical properties. Previous studies have shown that these steels are prone to precipitation of secondary phases, such as sigma phase (σ), chi phase (χ), Laves-phase, carbides, nitrides or secondary austenite, when exposed at elevated temperatures, directly affecting their mechanical properties and corrosion behaviour. A detailed study of the effect of isothermal ageing on the microstructure of S32654 (Fe-24Cr-21Ni-7Mo-0.5N-0.013C) and S31254 (Fe-20Cr-18Ni-6Mo-0.2N-0.012C) superaustenitic stainless steels was carried out. Samples were aged within the temperature range of 650οC to 950οC for times up to 3000 h. Following ageing, precipitation of secondary phases was clearly observed with precipitates varying in volume fraction, size, shape and spatial distribution. Several secondary phases were identified via transmission electron microscopy (TEM) and electron diffraction (ED). The orientation relationships between the austenitic matrix and the secondary phases were identified. Interaction and also phase transformation among different types of precipitates, such as between precipitates and the austenitic matrix were observed and an attempt of understanding these phase transformations was carried out.
Publisher
Trans Tech Publications, Ltd.
Subject
Condensed Matter Physics,General Materials Science,Atomic and Molecular Physics, and Optics
Reference19 articles.
1. K.H. Lo, C.H. Shek, J.K.L. Lai: Mater. Sci. Eng. R, Vol. 65 (2009), p.39.
2. V.G. Gavriljuk, H. Berns, in: High Nitrogen Steels – Structures, Properties, Manufacture, Applications, 1999, Springer – Verlang Berlin Heidelberg.
3. G. Stein, I. Hucklenbroich, H. Feichtinger: Mater. Sci. Forum, Vol. 318-320 (1999), p.151.
4. Ping Liu, in: Phase Analysis in Steel using Analytical Transmission Electron Microscopy, First Edition, 2004, Sandvik Materials Technology, ISBN 91-361-4272-4.
5. T. Koutsoukis et al.: Mater. Sci. Tech, (2009), DOI. 10. 1179/026708309X12506933872748.
Cited by
16 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献