Method of preventing fuel thermal degradation deposits

摘要

A method for preventing the deposit on a metal surface of thermal hydrocarbon degradation products derived from hydrocarbon fluid containing sulfur, oxygen and mixtures thereof comprises applying to the metal surface a diffusion barrier material or a catalytic material. The layer may be catalytically-inactive and inhibit the formation of coke in the fluid or catalytically-active and promote the formation of a loosely adherent coke in the fluid while inhibiting the formation of gum in the fluid. Preferred catalytically-active and catalytically-inactive materials are metal oxides, such as zirconium oxide and amorphous tantalum oxide respectively. The coating materials, i.e. the diffusion barrier coating material and the catalytic coating material, must be deposited by the effusive chemical vapor deposition of an organometallic compound on the surface without the use of carrier gas, without pre-oxidation of the surface and without thermal decomposition of the diffusion barrier material or the catalytic coating material. Articles having the coated surfaces find utility in components subjected to high temperatures wherein the components are in contact with hydrocarbon fluids without additives, without special attention to quality control and without the need for special processing.