Korrosie van vergasserkonstruksiemateriale in kontak met etanol-petrol-brandstofmengsels

Abstract

Afrikaans: Dit is bekend dat aluminiumallooie wat meer as 4,5% koper bevat korrosieprobleme ondervind wanneer dit in kontak met enkelfasige petrol-alkoholmengsels is, mits die tempe= rature hoer as 60°c is. Hierdie ondersoek het getoon dat ernstige korrosieprobleme hul ook met aluminiurnallooie in kontak met petrol-alkohol= mengsels voordoen, wanneer 'n aqua-fase as tweede fase uitskei. 'n Aqua-fase skei uit wanneer die waterinhoud die maksimum watertoleransie van die petrol-alkoholrnengsel vir die heersende bedryfstoestande oorskry. Korrosietempo's is onder rneer 'n funksie van bimetaalkoppeling aan koper= legerings en die teenwoordigheid van isobutanol en chloried. Voorsorgrnaatreels behels eerstens die beperking van water= opname deur die petrol-alkoholmengsel. Verder kan geskikte stremmiddels soos bensotriasol en Preventol CI-2 ('n Bayerproduk) wat korrosie in die aqua-fase beperk, gebruik word.

Aluminium alloys, containing 4,5% Cu or more, are subject to corrosion when in contact with petrol-alcohol mixtures at temperatures of 60°c and higher. Aluminium alloys are also subject to serious corrosion when they are in contact with the aqueous phase of petrol-ulcohol mixtures. Copper content and the temperature are important parameters, but are not prerequisites for a corrosion system. Phase separation occurs when the water content exceeds the maximum water tolerance of the petrol-alcohol mixture for prevailing conditions. Corrosion rates are determined by the bimetallic coupling to copper alloys, and by the presence of isobuthanol and chlorides. Phase separation of fuels must be prevented by effectively limiting water content. Suitable corrosion inhibitors like benzotriazole and Preventol CI-2 (Bayer product) can be added to reduce corrosion in the aqueous phase.