Patent ID: 7615144

Claim:
In a thermal cracking process wherein a hydrocarbonaceous feed is to be cracked in a furnace having a convection zone and a radiant zone, said hydrocarbonaceous feed being of a chemical nature that tends to form coke in said convection zone, said convection zone containing at least one of (1) at least one sinusoidal conduit for conducting said feed through said convection zone, (2) at least one cross-over conduit, and (3) at least one transfer conduit, at least one of said sinusoidal convection conduit, cross-over conduit, and transfer conduit containing at least one bend filling having an interior surface that is exposed to said feed and erosion there from as said feed passes there through, the improvement comprising at least one of said bend fittings having over at least a portion of said interior surface that is subject to erosion at least one layer of hard facing comprising a steel carrier and carbide pellets composed of submicron hard particles cemented with a metal binder.