Abstract Compression testing was used to explore the influence of strain rate on the formation of deformation induced ferrite. Samples of a 0·4%C–1·4%Mn plain C–Mn steel were heated to 1225°C, cooled to test temperatures in the range 1100–610°C, and then given a true strain of 0·6, at strain rates of3 × 10−2, 3 × 10−3, and 3 × 10−4 S−1. At the lowest strain rate it wasfound that the strain to peak stress decreased with decreasing temperature in the range 750–610°C. This behaviour is related to the formation of thin films of the softer deformation induced ferrite at the γ grain boundaries at the higher temperatures, and spheroidisation at the lower temperatures. More normal stress–strain curves were observed at the higher strain rates, as raising the strain rate prevents the formation of deformation induced ferrite and delays spheroidisation. The strain rate was also found to have an important influence on the extent of recovery in the deformation induced ferrite; the lowest strain rate enabling full recov...