To characterize the actual local long term operating conditions, possible deviations in them and the material condition, it is essential to be able to understand and evaluate the time and temperature dependent change of high temperature structural materials of power and process plants. In this paper the thermal degradation of selected steels is discussed with comparison of materials extracted from plant after long term service and similar materials thermally exposed to simulating heat treatment (controlled annealing). In general, such comparisons can be used to assess for example the effective in-service temperatures. However, there are also caveats to consider, such as variation of the initial composition and heat treatments, impact of stress-activated component of diffusion, and the material-dependent differences in the kinetics of different aspects of microstructural degradation. Examples are given to illustrate the observed influence of these factors of uncertainty.
|Title of host publication||Heat treatment and surface engineering: from tradition to innovation|
|Subtitle of host publication||European Conference on Heat Treatment 2015 & 22nd IFHTSE congress|
|Publisher||Associazione Italiana di Metallurgia AIM|
|Publication status||Published - 2015|
|MoE publication type||A4 Article in a conference publication|
|Event||European Conference on Heat Treatment 2015 & 22nd IFHTSW Congress Heat Treatment and Surface Engineering - Venice, Italy|
Duration: 20 May 2015 → 22 May 2015
|Conference||European Conference on Heat Treatment 2015 & 22nd IFHTSW Congress Heat Treatment and Surface Engineering|
|Period||20/05/15 → 22/05/15|
Auerkari, P., Yli-Olli, S., & Tuurna, S. (2015). In-service and simulated thermal transformation of steels for high temperature applications. In Heat treatment and surface engineering: from tradition to innovation: European Conference on Heat Treatment 2015 & 22nd IFHTSE congress Associazione Italiana di Metallurgia AIM.