Hot strips of low carbon steels with Ti additive (containing 0.04~0.07%C, 0.6% Si, 0.6% Mn, 0.06~0.14 %(mass) Ti) produced by EAF-CSP (Electric Arc Furnaces -Compact Strip Production) process have been examined by TEM, HREM and XRD. Titanium carbonitrides with different C/N ratio were found in the samples. The varying composition of the Ti-carbonitrides is resulted from the supersaturation of Ti, N and C in the steel and the temperature at which the compound form. It is pointed out by XRD analysis that the mass fraction of the extracted powder is about 0.305% of the specimen in total. Among them about four fifths are cementite, the remains are mainly titanium carbonitrides, carbides, nitrides, sulfide and oxides.
Particle arrays formed through the interphase precipitation are observed either in the slabs or in the hot strips. The dominating reaction mechanism is discussed. Compared with the conventional cold charge process, small addition of Ti would be more effective for precipitation of fine precipitates in the steels produced by CSP process.