Compositional Variants of Cu-rich Precipitate in Thermally Aged Ferritic Steel

Atom probe tomography was utilized to investigate Cu precipitation in a high-strength low-alloy steel isothermally aged at 500 °C for 1, 4, 16, and 64 h after water-quenching from 900 °C. With prolonged aging time, the Cu-rich precipitates (CRPs) increased in size and decreased in number density, and gradually evolved from spheroidal to elliptical in morphology. The small CRPs were rich in a high amount of Fe and a certain amount of Ni and Mn at...