Study of Pieces of the Ensenada de Barragán Fort Historical Museum by Non-destructive Testing

The Barragán Fort was built in 1731, at the time of the Spanish Viceroyalty of the Río de La Plata. The Ensenada de Barragán was a defense site against various invasion attempts by Portuguese, English and Anglo-French forces between 1730 and 1847. Cannonballs and bayonets found at the site have been analyzed by non-destructive metallography, X-ray fluorescence and Brinell hardness, to preserve the integrity of the historical pieces. The studies have revealed that the surface microstructure of cannonballs corresponds to a white cast iron, with Brinell hardness between 450 and 480 HB. The bayonets presented a ferritic structure, with recrystallized grains and oriented silicate-type inclusions. Hardness values were between 100 and 130 HB. It is presumed that the bayonets were made by the direct reduction method and later hot worked by hammering.