Nanoscale lamellae in an oxide dispersion strengthened steel processed by dynamic plastic deformation

The microstructure of an oxide dispersion strengthened ferritic PM2000 steel with a strong initial 〈100〉 texture has been investigated after compression by dynamic plastic deformation (DPD) at room temperature to a strain of 2.1. Measurements using electron backscatter diffraction and transmission electron microscopy indicate that DPD along the 〈100〉 direction results in a lamellar-type microstructure, in which lamellae of the 〈100〉 orientation alternate with 〈111〉 lamellae. These lamellae have a common rotation 〈110〉 axis in the compression plane. The microstructure is quite heterogeneous, where regions containing very narrow lamellae (with 〈111〉 lamellae as narrow as 20−40 nm) and regions of comparatively broad lamellae are found.