Interaction of Carbon, Titanium, and Boron in Micro-Alloy Steels and Its Effect on Hot Ductility

Varying contents of carbon, titanium and boron were used in the base steel composition 0.30 wt% Si, 2.0 Mn, 0.006 S, 0.03 Nb, 30–35 ppm N. Hot ductility tests performed with Gleeble-3800, after sample was in-situ melted, solidified, cooled to test temperature. Investigation completed thermodynamic kinetic simulations. The best results obtained for steels containing 58–100 B 35 Ti. They showed very good hot 80–50% RA within temperature range between 1250 °C 800 °C. It shown that effective improving ductility. Titanium protected from binding into BN low enough prevent excessive (Ti,Nb) carbonitride precipitation, which both could decrease Boron precipitated along austenite grain boundaries as iron boride Fe2B beneficial steel.