Atom probe analysis of clusters and precipitates in severely deformed and annealed interstitial free steel

Atom probe tomography (APT) was used to study the evolution of clusters and fine precipitates during the annealing of severely deformed interstitial free steel. No dissolution of pre-existing Ti₄C₂S₂ and FeTiP precipitates occurred during room temperature equal channel angular pressing (ECAP) and subsequent cold rolling. Ti rich clusters in the matrix may serve as precursors to even further precipitation at longer annealing times. While all fine precipitates detected by APT exhibited a variety of non-stoichiometric compositions, near equilibrium composition was found in the order of magnitude coarser precipitates observed by TEM.