Effect of Titanium Nitride, Carbonitride and Carbosulfide Precipitates on Properties of Low Alloy Steel.

Low Carbon steel samples were both shot into
and inoculated with Titanium in order to improve
mechanical properties such as strength and
toughness. SEM observations and X-Ray analyses
revealed that Titanium Nitride and Titanium
Carbonitride precipitates being scattered in the
ferrite substrate reduce the grain size in all
as-cast, Heat-treated and as-rolled cases. The
growth of the grains at higher temperatures was
observed in Titanium microallyed samples to be
slower than that for the low Carbon steel ones.
SEM stuides showed that Titanium Carbosulfide
inclusions [(Ti, Fe, Mn) C S 1 can be produced in
Titanium microalloyed specimens instead of
manganese sulfide inclusions. Titanium
carbosulfied inclusions are stiff and, therefore,
cannot be deformed even with high deformation
processing of the samples. Enhancement of the
impact shelf energy, toughness and cold
formability in the transverse direction is therefore
being achieved with addition of Titanium into the
samples.