Patent ID: 8647449

Claim:
An iron-based alloy having a microstructure comprising a fine-grained matrix, wherein the ferritic matrix comprises: Nb-carbide precipitates having sizes less than 10 μm; and hard precipitates having grain sizes less than 10 μm and comprising at least two of Mo, W, C, and B; wherein the alloy has a Rockwell C hardness greater than 50; and wherein the alloy comprises a combination of one or more of the following alloy chemistries, given in weight percent: Fe 76.62 Cr 5.12 Nb 4.27 V 2.7 C 1.07 B 0.82 W 7.6 Ti 0.2 Si 0.5 Mn 1.1 ; Fe 76.99 Cr 5.12 Nb 4.27 V 2.7 C 0.7 B 0.82 W 7.6 Ti 0.2 Si 0.5 Mn 1.1 ; Fe 76.89 Cr 5.12 Nb 4.27 V 2.7 C 0.8 B 0.82 W 7.6 Ti 0.2 Si 0.5 Mn 1.1 ; Fe 76.79 Cr 5.12 Nb 4.27 V 2.7 C 0.9 B 0.82 W 7.6 Ti 0.2 Si 0.5 Mn 1.1 ; Fe 83.93 Cr 5 Nb 4.3 V 0.5 C 0.8 B 1.25 W 3 T 0.2 Si 0.52 Mn 0.5 ; Fe 81.68 Cr 5 Nb 4.3 V 0.5 C 0.8 B 2.5 W 4 Ti 0.2 Si 0.52 Mn 0.5 ; Fe 80.4 Cr 5 Nb 4.3 V 0.5 C 0.8 B 3 W 2 Ti 0.2 Si 0.65 Mn 1.15 ; Fe 82.45 Cr 5 Nb 4.3 V 0.5 C 0.8 B 1.25 Mo 3 Ti 0.2 Si 2 Mn 0.5 ; Fe 82.1 Cr 5 Nb 4 V 0.5 C 0.8 B 0.9 Mo 3.5 Ti 0.2 Si 2 Mn 1 ; Fe 79.1 Cr 5 Nb 4 V 0.5 C 0.8 B 0.9 Mo 3.5 Ti 0.2 Si 5 Mn 1 ; Fe 82.95 Cr 5 Nb 4.3 V 0.5 C 0.8 B 1.75 Mo 3 Ti 0.3 Si 0.4 Mn 1 ; Fe 82.75 Cr 5 Nb 4.3 V 0.5 C 0.8 B 1.95 Mo 3 Ti 0.3 Si 0.4 Mn 1 ; Fe 83.45 Cr 5 Nb 4.3 V 0.5 C 0.8 B 1.25 Mo 3 Ti 0.3 Si 0.4 Mn 1 ; Fe 88 Cr 3 Nb 4.3 V 0.5 C 0.8 B 1 Mo 2 Ti 0.3 Si 0.4 Mn 1 ; Fe 84 Cr 3 Nb 3 V 1.4 C 0.8 B 1.1 W 5 Ti 0.3 Si 0.4 Mn 1 ; Fe 85.21 Nb 3.44 V 1.6 C 0.8 B 1.25 W 6 Ti 0.3 Si 0.4 Mn 1 ; Fe 81.15 Nb 4 B 1 C 2 W 11.45 Si 0.15 Ti 0.25 ; Fe 81.05 Nb 4 B 2 C 1.1 W 11.45 Si 0.15 Ti 0.25 ; Fe 80.15 Nb 4 V 1 B 1 C 2 W 11.45 Si 0.15 Ti 0.25 ; Fe 81.15 Nb 4 V 1 B 1 C 1 W 11.45 Si 0.15 Ti 0.25 ; and Fe 82.05 Nb 4 B 1 C 1.1 W 11.45 Si 0.15 Ti 0.25 .