Rupture strength prediction of martensitic power plant steels

ABSTRACTThe creep resistance of martensitic power plant steels depends strongly on the dispersion of various types of precipitates in the microstructure. Reliable prediction of rupture strength of such alloys thus demands accurate description of the microstructure evolution during service. A material model that calculates the simultaneous precipitation kinetics and hardening in these steels has been reported previously. The creep rupture model reported here is a natural extension of the previous research. This model has been validated against experimental creep rupture data of wide-used 9–12% Cr steels. It allows the effect of variation in alloy conditions, such as composition and heat treatments, on rupture strength to be quantitatively evaluated for a given alloy grade. Results show that such variations can lead to significant differences in the calculated rupture strength, which are believed to be largely responsible for the wide scatter in the experimental data.KEYWORDS: Rupture strengthrupture lifeprecipitationpower plant steelsmaterials modelling Disclosure statementNo potential conflict of interest was reported by the authors.