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.
