An article of manufacture comprising an alloy forming a material comprising: a matrix having a FCC-BCC transition temperature at or below about 950K; and extremely hard particles exhibiting a hardness of about 1000 Vickers or greater, the extremely hard particles having: an extremely hard particle fraction greater than about 5 mole % or greater; and an extremely hard particle melt range of about 200K or less, the material further comprising: at least about 90% volume fraction austenite in the matrix; a fraction of the extremely hard particles of about 5 volume % or greater; an ASTM G65 abrasion loss of about 1.5g or less; a relative magnetic permeability of about 1.03μ or lower; and a corrosion resistance of about 0.127 mmy or less in salt water according to ASTM G31; wherein the matrix does not contain any extremely hard particles that begin to form at a temperature greater than about 200K above a formation temperature of the matrix, and wherein: the article of manufacture comprises, in weight percent: C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; or, the article of manufacture comprises, in weight percent: C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15 the balance being Fe and incidental impurities. a matrix having a FCC-BCC transition temperature at or below about 950K; and extremely hard particles exhibiting a hardness of about 1000 Vickers or greater, the extremely hard particles having: an extremely hard particle fraction greater than about 5 mole % or greater; and an extremely hard particle melt range of about 200K or less, the material further comprising: at least about 90% volume fraction austenite in the matrix; a fraction of the extremely hard particles of about 5 volume % or greater; an ASTM G65 abrasion loss of about 1.5g or less; a relative magnetic permeability of about 1.03μ or lower; and a corrosion resistance of about 0.127 mmy or less in salt water according to ASTM G31; wherein the matrix does not contain any extremely hard particles that begin to form at a temperature greater than about 200K above a formation temperature of the matrix, and wherein: the article of manufacture comprises, in weight percent: C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; or, the article of manufacture comprises, in weight percent: C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15 the balance being Fe and incidental impurities. an extremely hard particle fraction greater than about 5 mole % or greater; and an extremely hard particle melt range of about 200K or less, the material further comprising: at least about 90% volume fraction austenite in the matrix; a fraction of the extremely hard particles of about 5 volume % or greater; an ASTM G65 abrasion loss of about 1.5g or less; a relative magnetic permeability of about 1.03μ or lower; and a corrosion resistance of about 0.127 mmy or less in salt water according to ASTM G31; wherein the matrix does not contain any extremely hard particles that begin to form at a temperature greater than about 200K above a formation temperature of the matrix, and wherein: the article of manufacture comprises, in weight percent: C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; or, the article of manufacture comprises, in weight percent: C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15 the balance being Fe and incidental impurities. at least about 90% volume fraction austenite in the matrix; a fraction of the extremely hard particles of about 5 volume % or greater; an ASTM G65 abrasion loss of about 1.5g or less; a relative magnetic permeability of about 1.03μ or lower; and a corrosion resistance of about 0.127 mmy or less in salt water according to ASTM G31; wherein the matrix does not contain any extremely hard particles that begin to form at a temperature greater than about 200K above a formation temperature of the matrix, and wherein: the article of manufacture comprises, in weight percent: C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; or, the article of manufacture comprises, in weight percent: C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15 the balance being Fe and incidental impurities. the article of manufacture comprises, in weight percent: C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; C: about 2.5 to about 4.5; Cr: about 11.5 to about 16.5; Mn: about 8.5 to about 14.5; and V: about 10.0 to about 16.0, the balance being Fe and incidental impurities; or, the article of manufacture comprises, in weight percent: C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15 the balance being Fe and incidental impurities. C: about 2.5 to about 4; Cr: about 10.8 to about 16; Mn: about 9.5 to about 14; and V: about 13.5 to about 15