Badania nad technologią wybranych zabytków żelaznych (Research on the technology of selected iron artefacts)
by Mateusz R. Biborski 1, Marcin J. Biborski 1, Janusz Stępiński 2
1 – Laboratorium Archeometalurgii i Konserwacji Zabytków Instytut Archeologii Uniwersytetu Jagiellońskiego, ul. Gołębia 11; 31-007 Kraków; 2 – Wydział Inżynierii Metali i Informatyki Przemysłowej, Katedra Metaloznawstwa i Metalurgii Proszków
Akademia górniczo-Hutnicza w Krakowie, Aleja Mickiewicza 30; 30-059 Kraków
In: M. Cieślak-Kopyt, D. Pogodzińska 2020. Żelazna Nowa, stanowisko 2. Cmentarzysko kultury przeworskiej z Zapilcza na południowym Mazowszu, Ocalone Dziedzictwo Archeologiczne 10, Radom – Pękowice: Muzeum im. J. Malczewskiego w Radomiu, Wydawnictwo Profil-Archeo, p. 135-144.
Summary: The extensive programme of research on artefacts recovered from the Przeworsk culture cemetery in Żelazna Nowa, Comm. Magnuszew, included performing a series of metallographic analyses. Only three objects were subjected to the analyses due to their good preservation: two knives and a shield grip fragment. The aim was to determine the technology of manufacture of particular objects and to identify the raw materials from which they were forged. Microstructure was examined using a Leica DMLM metallurgical microscope, and the observed metal structures were photographed. In addition, metal hardness was measured using the Vickers method, with a load of 10 kG (98N). Carbon content of steel was determined based on microscopic observation. As demonstrated by the analyses, the artefacts were made from metal obtained through the bloomery process from bog iron with a significant admixture of phosphorus.
The technology used for manufacture of the analysed artefacts was not particularly sophisticated. They were forged from single pieces of bloomery iron. The only exception is a knife (inv. no. CCLII/15), which was forged from two different pieces of metal welded together, namely from a piece of high phosphorus iron and a piece of soft steel. This made the knife more flexible, while rendering its blade sufficiently hard and more resistant to abrasion. One cannot rule out that the blades of both knives were originally hardened by local carburisation, in connection with later thermal processing (quenching). The results of metallographic research seem to support our assumptions. The two knives and the shield grip were manufactured in local Przeworsk culture workshops, perhaps from iron originating from the centre of metallurgy in the Mazowsze (Mazovia) region.