Abstract
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The effects of small titanium and nitrogen additions on the mechanical properties and
microstructural characteristics of four different low carbon, low manganese steels have been
studied using a Gleeble thermomechanical simulator and TEM investigations. The Ti/N ratio in
these steels as well as the size and distribution of TiN particles play a major role in determining the
mechanical properties, the resulting austenite grain size as well as the size of inclusion
precipitates. The best mechanical properties were obtained in the steel with a Ti/N ratio lower than
the stoichiometric value. This steel also had the smallest austenite grain size after reheating as
well as the highest rate of dynamic recrystallisation during hot deformation. The nature and rate of
recrystallisation seem to be determined by an intricate interplay between the size and distribution
of titanium nitrides and the prevailing austenite grain size.