Microstructural Evolution of Ultra Fine Grained C-Mn Steel Warm Rolling and Intercritical Annea

The attainment of finer ferrite grain structure in low carbon is object of interest because significantly higher yield strengths and lower ductile-brittle transition temperatures can be predicted at the same time with ultra-fine grain sizes. This work verified the microstructural evolution of a low carbon 0.15%C-1.39%Mn steel after an ice brine quenching from 1200 °C followed by warm rolling and intercritical annealing at 800 °C at different times. To compare the final microstructure, a first group of specimens were heated at temperatures in the range from 660 °C to 800 °C during 30 min an...