Material behaviour and plant experience of P91/P92 components

Abstract

In several lignite-fired power plants of the ‘Vattenfall Generation AG’ in Germany components of P91/P92 material are used in long-time operation. About this experience in operation of selected components will be reported. In this context own experimental results of a research project in the damage evolution will be presented. The project ‘Damage development III’ was edited together with the MPA Stuttgart and was supported by Vattenfall and AVIF. The aim of the project was to improve the knowledge about the process of creep damage by experimental tests and additional numerical calculations. An instruction was given for planning, implementation and analysis of recurrent investigations on components consisting of 9% Cr steels which are subjected to high operation loading. Finally, the damage phenomena are presented by two case studies, a damage in a pipe bend due to faulty heat treatment and the creep-crack assessment of a lack of side-wall fusion in a reheater weld by fracture mechanics.

Keywords:

• Material behaviour
• 9% Cr steels
• plant experience
• component test
• FE calculation
• damage development

Acknowledgements

The work presented in this paper was financial supported by the European Commission (R&D projects HIDA, WELDON, INTEGRITY), which is gratefully acknowledged. The authors wish to thank the Forschungsvereinigung der Arbeitsgemeinschaft der Eisen und Metall verarbeitenden Industrie e.V. (AVIF) for financial support within the R&D Project A 229: Criteria for damage development of high-temperature components made of martensitic 9–11% Cr-Steels.