Patent ID: 7935198

Claim:
An iron based alloy weld overlay applied on a substrate comprising: an iron based alloy including 55% to 65 at % Fe, 7 at % to 16% Cr, 0.5 at % to 8 at % Nb, 13 at % to 22 at % B and 2 at % to 7 at % C; wherein said alloy is a nanocrystalline weld overlay material and exhibits a hardness when applied to said substrate and cooled at a rate sufficient to provide greater than or equal to Rc 64 and a Vickers Hardness in the range of 800 kg/mm 2 to 1700 kg/mm 2 , wherein the iron based alloy comprises a Fe rich phase containing at least 30 atomic percent iron wherein said Fe rich phase is present in the range of about 40 to 80% by volume and range from 2.0 to 5.0 microns in size, chrome rich borocarbide phases containing at least 30 atomic percent chromium wherein said chrome rich phase is present in the range of about 10 to 50% by volume and range from 1 to 50 microns in size, and niobium rich borocarbide phases containing at least 30 atomic percent niobium wherein said niobium rich phase is present in the range of about 1 to 10% by volume and said niobium rich phase is 0.01 to 5 microns in size and said hardness is attained within 250 microns from the substrate surface and wherein said alloy exhibits a mass loss of less than 0.15 grams as measured by ASTM G-65 Procedure A.