Patent ID: 8317940

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 150° 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 comprises from about 50 to about 95 vol % of the volume of said cermet lining or insert, wherein said ceramic phase comprises a chromium carbide selected from the group consisting of Cr 23 C 6 , Cr 7 C 3 , Cr 3 C 2 and mixtures thereof; and said metal binder phase is selected from the group consisting of (i) alloys containing, based on the total weight of the alloy, about 60 wt % to about 98 wt % Ni; about 2 wt % to about 35 wt % Cr; and up to about 5 wt % of an element selected from the group consisting Al, Si, Mn, Ti and mixtures thereof; and (ii) alloys containing about 0.01 wt % to about 35 wt % Fe; about 25 wt % to about 97.99 wt % Ni, about 2 wt % to about 35 wt % Cr; and up to about 5 wt % of an element selected from the group consisting of Al, Si, Mn, Ti and mixtures thereof, and wherein said ceramic phase 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 the size range of about 61 to 800 microns.