Effect of Ti-doping on peeling resistance of primary M7C3 carbides in hypereutectic Fe Cr C hardfacing coating and γ-Fe/M7C3 interfacial bonding strength

• The hardness and wear resistance of the Fe Cr C hardfacing coating are improved after adding Ti element. • The orientation relationship of eutectic austenite/primary M 7 C 3 carbide is γ-Fe(1 1 1)//(Cr, Fe) 7 C 3 (1 0 1 ¯ 0). • Ti-doping can effectively inhibit the initiation and propagation of cracks. • The interfacial adhesion strength of γ-Fe//M 7 C 3 is enhanced after adding Ti element. Alloying element Ti plays an important role in improving the mechanical properties of hypereutectic Fe Cr C hardfacing coating, but its peeling resistance have been neglected. Here, the hardness and wear rate of the hypereutectic Fe Cr C and Fe Cr C Ti hardfacing coatings were measured. The crystal structure and orientation relationship of primary M 7 C 3 carbide and eutectic austenite matrix were confirmed. Then, the interface properties of γ-Fe//M 7 C 3 (Ti) interface were calculated by first principles. The results show that the micro-Vickers and macroscopic Rockwell hardness of the Fe Cr C Ti hardfacing coating are increased, and its wear rate is decreased from (4.33 ± 0.333) × 10 −6 mm 3 /Nm to (3.64 ± 0.366) × 10 −6 mm 3 /Nm. The Ti-doping can effectively inhibit the initiation and propagation of cracks and improve the peeling resistance of M 7 C 3 carbide. Meanwhile, the orientation relationship of eutectic austenite/primary M 7 C 3 carbide is γ-Fe(1 1 1)//(Cr, Fe) 7 C 3 (10 1 ¯ 0). Among C Fe1, Cr Fe1 and Fe Fe1 interfaces, interface energy of Fe Fe1 model is the smallest (1.954 J/m 2 ), and its adhesion work ( W ad ) is the largest (0.756 J/m 2 ). Moreover, W ad of Ti-doped interface (4.123 J/m 2 ) is larger than that of Fe Fe1 one (3.045 J/m 2 ) after relaxed, which indicates Ti-doping is beneficial to enhance adhesive strength between γ-Fe//M 7 C 3 interfaces, which improves the peeling resistance of M 7 C 3 carbide.