Fatigue performance of stabilized austenitic stainless steels in terms of environmental fatigue factors, temperature and hold time effects

Experimental research on fatigue performance of niobium stabilized stainless steel (1.4550, X6CrNiNb1810mod) relevant for German NPP primary piping has demonstrated good long life performance while relevance and general applicability of the new design curve in ASME III, which was already introduced in the 2009 addendum, was questioned in general. Effects of temperature, environment and operational loading sequences are currently being studied in terms of applying laboratory data to real plant components. The publication will cover a discussion of these effects including qualification and quantification and will state new experimental investigations. (orig.)