Nanostructured Low Carbon Steels Obtained from the Martensitic State via Severe Plastic Deformation, Precipitation, Recovery, and Recrystallization

Abstract

The range of accessible microstructures from the combination of severe plastic deformation (SPD) and heat treatments of a low carbon steel martensite under various processing conditions is evaluated. SPD results in a temperature decrease for recrystallization and austenitization upon subsequent annealing. On the contrary, the precipitation of cementite takes place at higher temperatures after SPD. Whereas, a certain thermal stability is observed for subsequent processing, even low annealing temperatures have a strong impact on the results of simultaneous SPD and heat treatments which results from the differences of dynamic and static recovery. It is shown that with each processing sequence unique microstructures can be produced that have to be taken into account in order to produce a material with optimized tailored properties.