Didn't get very far with this one. Google insists DEL should have been DE; this may be because it is in Spanish, rather than in Portuguese as the token is assigned to Argentina, Buenos Aires province. Token listed in Rulau as BUE 110.
Steel tokens do exist in quantity, notably among French and German war year tokens of the 1916-1923 period. Argentina has known a large number of financial crisis and too many periods of rapid inflation, which may explain the use of steel. Another possibility is that the token was clad and the cladding was washed off with diluted acid.
Peter