Investigation of thermal stability of die steel deposited with N13M5KH4FSTYUR flux-cored wire

The results of the investigation of heat-resistant properties of the metal deposited with the flux-cored wire N13M5Kh4FSTYuR composed of boron carbide, titanium diboride and zirconium diboride in the amount of 2.5 % are presented. For comparison heat resistance of the weld metal obtained by materials produced by the company Castolin-Eutectic, such as electrodes Castolin 6, wire CastoMag 45355 and rubber stamp steels 50KhNM was determined. It is shown that metal deposited with the flux-cored wire N13M5Kh4FSTYuR with borides in heat stability at temperatures up to 650 °C corresponds to the level of the metal deposited with electrodes Castolin 6, but at higher temperatures it significantly excels materials investigated in this study. It has been established that hardening the metal deposited with flux-cored wire N13M5Kh4FSTYuR, unlike conventional maraging steels occurs due to the release of fine intermetallic Laves phases (Fe, V, Si)2(Mo, Ti) and highly durable low solubility carboboride phases of round (Ti, Mo, Fe, V)23(С,В)6 and lamellar (Сr, Fe, Mo, Ti)7(С,В)3 forms. Besides, the addition of borides to this metal leads to the formation of carboboride eutectic (Fe, Ti, Mo)3(C, B) having a skeletal nature and a grain boundary location. Such structural condition increases the recrystallization temperature and slows diffusion processes at high temperatures, therefore, annealing of the deposited metal to the temperature of 750 °C has no significant effect on the structure change. This flux-cored wire N13M5Kh4FSTYuR with borides is recommended as the coating material to restore and improve the wear resistance of die tooling and metallurgical equipment parts.