Archaeologists from Salzburg Museum and Salzburg University have unearthed a Roman estate from the 2nd and 3rd centuries A.D. The excavations yielded slags, steel balls, and steel rods (semi-finished products) showing that tools were repaired and steel balls were transformed into finished products in the estate’s forge.
Next to the components solidified from liquid slag – primary and secondary wuestite crystals, slab-shaped fayalite crystals and vitreous or crystalline remaining melt (segregated olivines) –, the slag fragments contain numerous lumps of charcoal infiltrated with slag as well as still unmolten but slag-laden flux material, such as quartz and carbonates.
The two steel balls consist of ferrite and perlite. Both structures are inhomogeneously distributed throughout the steel balls. The two steel rods consist, on the one hand, of ferrite with frequent inclusion of slag streaks, and, on the other, of perlite with grain boundary ferrite. The intergranular ferrite shows, in part, a Widmannstätten structure. The two steel rods are proof that the smiths working on the estate in the 2nd and 3rd centuries A.D. processed different steel grades to make a variety of objects for respective practical uses.