APFIM characterization of the spinodal decomposition in duplex stainless steels

摘要

An atom probe field ion microscope characterization of two CF3 steels with 15 and 25 volume percent ferrite aged at 400(degrees)C for up to 10,000 h and service materials from the Shippingport main and check valves aged for approximately 13 years at (approximately)280(degrees)C has been performed. In all these materials, the ferrite phase was found to have decomposed into an ultrafine scale two phase microstructure consisting of an iron-rich (alpha) phase and a chromium-enriched (alpha)(prime) phase. The scale of the decomposition in the Shippingport materials was much finer that than found in the CF3 material subjected to accelerated aging at 400(degrees)C. 20 refs., 9 figs., 3 tabs.