Effect of Titanium Addition on Microstructure and Properties of Nitrogen-Alloyed High Chromium Cast Iron

This paper investigates the effect of titanium alloying on the eutectic transformation of high-chromium cast iron (HCCI) containing a significant amount of nitrogen (2.4% C, 30% Cr, 0.1% N). The study was conducted under industrial conditions in a Polish foundry, with titanium added to liquid HCCI as ferroalloy. Maximum Ti concentrations did not exceed 1.5%. The influence of titanium was assessed via characteristic points on crystallization curves recorded by thermal analysis, compared to the equilibrium phase diagram modeled by Thermo-Calc software. Microstructure was examined by XRD and SEM-EDS, revealing TiN precipitation. Abrasion resistance was evaluated using the Miller test. Titanium addition slightly lowered the eutectic transformation temperature and shifted crystallization from eutectic to hypereutectic of HCCI and reduced cumulative mass loss by 35% in the Miller abrasion test.