SCATTER BANDS IN CREEP AND FATIGUE-CRACK - GROWTH-RATES IN HIGH-TEMPERATURE PLANT MATERIALS DATA

As a part of the European Commission supported project BE1702: 'HIDA' Creep, creep-fatigue, and high temperature fatigue crack growth data f or five high temperature plant steels were accessed from a number of p ublished and unpublished sources. These large sets of data were review ed, and re-analysed where necessary, and plotted in terms of various c rack growth rate correlating parameters. Thus limits of scatter bands and mean and upper 95% confidence limit creep and fatigue crack growth correlations are proposed. The present work covers a wide range of va riables such as test specimen geometries, sizes, loading conditions an d temperatures. Therefore, the correlations proposed are considered un iversal. However, it is envisaged that these correlations will be refi ned in future by enlarging the database and exploring the effect of th e variables described above. The five materials studied are AISI 316 s tainless, 2.25Cr1Mo, P91, 1CrMoV (forged), and 1CrMoV (cast) steel.