Metallurgical Evaluation of Farmer's Steelmaking in Finland

In this study, we have documented the reconstruction of Finnish traditional steelmaking methods using farmer's furnace in Mahko by a local blacksmith, and metallurgically analyzed the materials and products associated with this technology. The steelmaking was successfully recreated in 2007, including mining, furnace construction and operation, followed by forging. Compared with Swedish lake ores, the Finnish lake ore used contains higher iron and lower silicon, aluminum and phosphorus. The produced sponge iron, bloom (luppe), had a yield ratio estimated to be 43-67%. The carbon and oxygen contents near surface areas of luppe were C: 0.32 +/- 0.27 mass%, O: 1.20 +/- 0.79 mass%, respectively, and those at the centers are C: 0.06 +/- 0.06 mass%, O: 0.045 +/- 0.030 mass%, respectively. It lacked impurities excluding unexpectedly contaminating ore and slag debris. The reasons for higher yield and lower carbon content were discussed metallurgy.