Thermal microstructural degradation was investigated by isothermal annealing of samples from boiler tube steels St 35.8, 15 Mo 3, 13 CrMo 44, 10 CrMo 9 10 and X20 CrMoV 12 1 in the temperature range 600 - 780°C for up to 2 000 h. Optical and scanning electron microscopy and hardness testing were used for characterising the microstructural changes and their time-temperature dependence. The results suggest a simple and consistent time-temperature dependence for all investigated materials, expected to apply also to long term service beyond the annealing time range of the present work. This would allow assessment of the in-service thermal exposure from the observed microstructure. A collection of micrographs has been prepared for this purpose, to aid in classifying and evaluating the observed microstructural state in terms of isothermal exposure to high temperature.
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Number of pages||69|
|Publication status||Published - 1996|
|MoE publication type||Not Eligible|
- thermal degradation
Salonen, J., & Auerkari, P. (1996). Microstructural degradation of boiler tube steels under long term exposure to high temperature. VTT Technical Research Centre of Finland. VTT Publications, No. 280 http://www.vtt.fi/inf/pdf/publications/1996/P280.pdf