Phase Equilibrium and Microstructure Examinations of Eutectic Fe-C-Mn-B Alloys

Abstract

In this study, we analyzed the quaternary Fe-C-Mn-B system to create new eutectic cast alloys for coating deposition and additive manufacturing. Experimental samples were fabricated via the wire arc manufacturing method with argon shielding using Kemppi Pro 5200 Evolution equipment. Annealing was performed in a vacuum electric furnace at 1273 K for 350 h. For phase analyses, Jeol Superprobe 733 equipment was used. Metallographic and differential thermal analyses were used to reveal the eutectic structure of the samples. Examinations of the quaternary Fe-C-Mn-B system demonstrated that several eutectic alloys existed in the system. Four isothermal pseudo-ternary sections of the Fe-C-Mn-B system were studied: “Fe3B”-Fe3C-“Fe3Mn”; Fe2B-“Fe2C”-“Fe2Mn”; “Fe3B”-Fe3C-“Fe1.2Mn”; “Fe23B6”-“Fe23C6”-“Fe23Mn”. Broad eutectic concentrations enabled us to overcome parameter fluctuations during additive manufacturing. In each isothermal section, two dissimilar phase regions were determined: one with a ternary Fe-C-B composition and the other with a ternary Fe-C-Mn composition. Depending on the manganese content, two types of solid solutions could be formed: (Fe, Mn)α or (Fe, Mn)γ.

Microstructure and Friction Response of a Novel Eutectic Alloy Based on the Fe-C-Mn-B System

“…The XRD spectra acquired from the surface are given in Figure 3. The analysis of diffraction patterns reveals that Cr7C3 and M2B 2B phases appeared in both samp [13,49,55,56]. The positions of the peaks in the X-ray diffraction profiles correspond to following phases: Figure 3a: γ-Fe (11.9%), α-Fe (7.9%), M2B 2B (3%), and Cr7С3 (59.4 Figure 3b: γ-Fe (5%), M2B (79%), and Cr7С3 (15%).…”

“…To produce the coating via the flux-cored wire, it was necessary to balance the composition of the filling powder (Table 1) to obtain the target alloy after fusion with the steel of the envelope. The powder mixture is an initially produced [49] eutectic alloy doped with Si, Ni, and Cr. Si increases the oxidation resistance and thus improves the weld surface quality, reducing the likelihood of hot cracks between the welds.…”

“…The M 2 B borides are more wear-resistant than carbides but are also harder and create more stress in the matrix. Based on our earlier published research [49], we decided to improve the performance of the basic Fe-C-Mn-B alloy with Cr, Mn, and Ni for solution strengthening and the (Cr) formation of carbides, and Si was used to reduce oxidation during the coating deposition process. The researched material is to be used as a coating to recondition the worn surfaces of car tire shredder blades.…”