M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)

Analysis - HEGEDŰS Zoltán: Metallography cal testing of iron artifacts from the iron smelter finding of Imola

METALLOGRAPHICAL TESTING OF THE IRON ARTIFACTS FROM THE IRON SMELTER FINDING OF IMOLA Diverse iron artifacts were found in course of the discovery of the findings from the iron smelter furnace at Imola [1] and metallographical tests were performed on a part of these. The tool visible in Fig. 1 has given interesting results. Near the edge (1st testing point) the structure is composed of fine grained ferrite with a varying quantity of perlite and elongated silicate inclusions and in the latter locally -are inclusions of FeO, too. Coming nearer to the edge the quantity of perlite increases. Fig.l The structure in the shaft segment (2nd testing point) is a ferrite-perlite and the quantity of silicate inclusions is less here. At the 3rd testing point the structure is martensitic throughout segment. The microhardness of individual segments of diverse structures measured with a load of 50 MPa is as follows: perlitic structure near the edge Hardness value (HV) = 277 — 265 - 241 perlitic structure of the shaft segment 161 - 165 - 157 martensitic structure of the shaft segment 613 — 726 — 516 The structure pattern of the tool in the unhardened segments shows 0.15 mass% (2nd testing point) but points relating to C-contents of 0.4-0.7 mass% could be found too, and the latter are consequences of the contemporary iron-melting process. At the edge of the tool (1st testing point) the structure refers to carburization. The great hardness of the martensite of the shaft segment is in accordance with hardening. A question that remains to be decided is that concerning why the mainly hardened edge segment requiring the greatest hardness remained soft, and why this should have occured.