Dislocation Driven Chromium Precipitation in Fe-9Cr Binary Alloy: A Positron Lifetime Study

摘要

The influence of initial heat treatment on anomalous Cr precipitation withinhigh temperature solubility region in Fe-9Cr alloy has been investigated usingpositron lifetime studies. Air-quenched samples with pre-existing dislocationsexhibited a distinct annealing stage in positron lifetime between 800 and 1100K corresponding to Cr-precipitation. During this stage, Transmission ElectronMicroscopy showed fine precipitates of average size 4 nm, dispersed throughoutthe sample and from EDS analysis they are found to be Cr-enriched. Theexistence of dislocations is found to be responsible for Cr precipitation.