HTGR Knowledge Base

Conference Article: Correlation between microstructure and the creep behaviour at high temperature of Alloy 800 H

Spiradek, K. (Institute of Nuclear Physics, Cracow (Poland)); Degischer, H.P. (Aluminium Ranshofen GmbH, Ranshofen (Austria)); Lahodny, H. (Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany, F.R.))

Abstract

A systematic metallographic study was performed to identify the nature of the microstructural changes occurring during high temperature creep deformation of Alloy 800 H. Creep tests were carried out at 800 deg. C under constant load conditions corresponding to the initial stresses between 25 and 80 MPa. Some tests were interrupted after certain elongations to provide the samples for electron microscopy. Emphasis was put on the creep periods relevant to design where only a few per cent of deformation are tolerable. The influence of the initial material conditions on the creep behaviour was examined. Variations of the initial microstructures were achieved by different solution treatments (980/1250) deg. C, preageing at 800 deg. C (0/6400) h and cold deformation up to 10% followed by ageing at 800 deg. C. The results of the microstructural examinations were correlated with the creep curves that provide a basis for identification of the creep mechanisms operating at the test conditions.

view the full text of this article (12 pages, format: PDF, size= 1333kB)

key words: Gas Cooled Reactor, Nuclear Technology
Reference:
High temperature metallic materials for gas-cooled reactors. Proceedings of a specialists meeting held in Cracow, 20-23 June 1988
International Atomic Energy Agency, Vienna (Austria). International Working Group on Gas-Cooled Reactors
IWGGCR--18, pp:51-62