Microstructural Map and Phase Chemical Compositions in Hybrid Multi-component Cast Alloys Fe–W–Mo–V–Cr–Ti–(1.5–3.5 Wt Pct)B–(0.3–1.1 Wt Pct)C

This article presents the systematic data on the effects of carbon and boron on the microstructure and phase elemental composition of the hybrid multi-component alloys, containing (wt pct) 5W–5Mo–5V–10Cr–2.5Ti–1Mn–1Si–Fe(balance). The nominal concentrations of boron were 1.5, 2.5 and 3.5 wt pct; at each boron level, the carbon content was 0.3, 0.7 and 1.1 wt pct. The following phases were identified in the alloys: (a) (W,Mo,V)-based borocarbide M₂(B,C)₅ (primary particles and eutectic fibers), (b) Ti-rich carboboride M(C,B) (primary dispersions); (c) (Cr,Fe)-rich carboboride M₇(C,B)₃ (eutectic lamellae); (d) boroncementite M₃(C,B) (eutectic plates); (e) matrix. Boron was responsible for the M₂(B,C)₅ formation while the M(C,B) was controlled by carbon. Boron and carbon change the eutectic carboboride type as follows: M₂(B,C)₅ → M₇(C,B)₃ → M₃(C,B). Furthermore, B and C deplete the matrix by chromium enabling the pearlite/martensite structure instead of ferrite. A microstructural map is proposed to select the composition for a specific wear condition.