Negligible creep temperature curves for EN-13445 : JRC contribution to CEN/TC 54/WG 59

The simplified methodology proposed by JRC (in CEN TC 54 WG CREEP) for defining negligible creep temperature curves (TNEC) has here been applied to define the negligible creep (TNEC) curves and the no creep temperature (TNC) for a service life of 200 000 hours for all the ferritic / ferritic-martensitic (F/M) steels in EN-10028-2 and the creep resistant austenitic steels in EN 10028-7. The curves are intended to be used in the revision of the European standard EN-13445. The work flow and methods used for the negligible creep temperature curves, based on the creep strength and tensile properties obtained from the standard tables, are described in detail and the TNEC curves are presented together with comments on encountered challenges for each steel. Note that the methodology uses data from the material standards only and that the calculated temperatures are dependent on the combination of the tensile properties and the creep rupture strength tables.