Patent ID: 8361244

Claim:
A method for protecting metal surfaces in oil & gas exploration and production, refinery and petrochemical process applications subject to solid particulate erosion at temperatures of up to 1000° C., the method comprising the step of providing said metal surfaces with a hot erosion resistant cermet lining or insert, wherein said cermet lining or insert comprises: a) a ceramic phase, and b) a metal binder phase, wherein said ceramic phase comprises from about 30 to about 95 vol % of the volume of said cermet lining or insert, and wherein said cermet lining or insert has a HEAT erosion resistance index of at least about 5.0 and a K 1C fracture toughness of at least about 7.0 MPa·m 1/2 , wherein said cermet lining or insert is a composition gradient cermet material produced by the steps of: heating a metal alloy containing at least one of chromium and titanium at a temperature in the range of about 600° C. to about 1150° C. to form a heated metal alloy; exposing said heated metal alloy to a reactive environment comprising at least one member selected from the group consisting of reactive carbon, reactive nitrogen, reactive boron, reactive oxygen and mixtures thereof in the range of about 600° C. to about 1150° C. for a time sufficient to provide a reacted alloy; and cooling said reacted alloy to a temperature below about 40° C. to provide a composition gradient cermet material, wherein said ceramic phase is (PQ), said metal binder phase is (RS) and further comprising X, wherein X is at least one member selected from the group consisting of an oxide dispersoid E, an intermetallic compound F and a derivative compound G, wherein said ceramic phase (PQ) is dispersed in said metal binder phase (RS) as particles of diameter in the range of about 0.5 to 3000 microns, and said X is dispersed in said metal binder phase (RS) as particle size range of about 1 nm to 400 nm, and wherein said ceramic phase (PQ) has a multimodal distribution of particles, wherein said multimodal distribution of particles comprises fine grit particles in the size range of about 3 to 60 microns and coarse grit particles in the size range of about 61 to 800 microns.