Influence of aluminium on creep strength of 9–12% Cr steels
2009 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, Vol. 527, 118-125 p.Article in journal (Refereed) Published
The influence of aluminium on creep strength of 9% Cr steels is predicted by a fundamental model forcreep. Through thermodynamic modelling the particle structure is determined for a temperature andcomposition range. This shows how AlN is formed at the expense of MX carbonitrides of VN characterwhen the aluminium content is increased. The remaining MX particles are of NbC type and have approximatelyone fifth of the original phase fraction. The evolution in microstructure such as particle coarseningis included in the model as well as the recovery. Rupture time is predicted using a modified Norton equationincluding back-stresses calculated from microstructure. The predictions show correspondence tosome of the creep data for the steel P91 over a temperature and stress range. Furthermore, simulationwith high Al content verifies the observed early failure of Al rich components. Overall, the simulationsshow a decrease in rupture time by a factor 6 due to Al additions of up to 0.2%.
Place, publisher, year, edition, pages
Elsevier , 2009. Vol. 527, 118-125 p.
Creep rate modelling, Aluminium influence, Dislocation evolution, Particle strengthening, Ferritic steels
IdentifiersURN: urn:nbn:se:kth:diva-12232DOI: 10.1016/j.msea.2009.07.060ISI: 000271611500017ScopusID: 2-s2.0-71749091664OAI: oai:DiVA.org:kth-12232DiVA: diva2:306587