MECHANICAL PROPERTIES OF P91 AND PB2 STEEL AFTER LONG-TERM AGEING AT 620°C

Abstract

The article presents the results of research on mechanical properties of martensitic steels, X10CrMoVNb9-1 (P91) and X13CrMo- CoVNbNB9-2-1 (PB2), as-received and after 50,000 hours of ageing at 620˚C. The scope of the tests of mechanical properties included a Vickers hardness test, Charpy impact test, and static tensile test. As received, the investigated steels were characterised by relatively high mechanical properties. The long-term effect of temperature and time contributed to a relatively slight decrease in the strength properties and hardness of the tested steels. However, a considerable decrease in the ductility of these alloys was observed. The decrease in mechanical properties after long-term ageing was smaller in the case of the PB2 steel, which was attributed to the beneficial effect of microalloying boron.