engleski

CORROSION RESISTANCE OF CHROMIUM CARBIDE COATINGS OBTAINED BY TRD PROCESS EXAMINED BY NOVEL MEASURMENT TECHNIQUE

Niobium and chromium carbide coatings, typically used for increasing hardness and wear resistance of metallic components, are capable of forming surface Nb2C5 and CrxCy carbides, known to exert premium corrosion resistance. The persistence of protective effect is dependant on the carbide protective ability, initial porosity of the coating as well as the porosity development with the time of exposure to corrosive influence. Protective performance may vary significantly and depends upon coarse features, such as surface irregularities and fine features, such as crystallite size. A novel technique, that uses a flexible, surface-mounted paste-electrolyte electrode suitable for laboratory and field use and is based on measuring complex resistance spectrum in a wide frequency range of input AC signal, has been applied. TDR produced Cr-C layers on ductile cast iron without and with Cu addition have been analysed. Electrical behaviour of oxide, carbide layer and metallic substrate dominated separate AC frequency ranges which enabled detailed system analysis.

Chromium Carbide ; Thermoreactive deposition ; Corrosion Resistance

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