Hardenability and corroson resistance of as cast Fe-9Al-0,6C alloy

Ratna Kartikasari¹, Soekrisno², M. Noer Ilman² and Suyitno²

Department of Mechanical Engineering, Technical Faculty, Gadjah Mada University Jl. Grafika No.2 Kampus UGM, Depok, Sleman, Yogyakarta - 55281 (Indonesia).

Received on April 20, 2010 and accepted on May 24, 2010

ABSTRACT

On the basis of economic considerations, Fe-Al-C alloy could be a good candidate for replacing some of the conventional stainless steel. Wherein, Al is used to replace the expensive alloy element in conventional Fe-Cr-C system. The aim of the research is to investigate harden ability and corrosion resistance of Fe-9Al-0,6C in the NaCl and H2SO4 solution. Thirty five kilograms of Fe-Al-C were prepared from mild steel scrap, high purity aluminium, and Fe-C. The alloy was prepared in an induction furnace under an argon atmosphere. Jominy test and microstructure were examined. And, the corrosion rate, were carried out with three-electrode polarization in 0.5% NaCl and 0.05M H2SO4. The corrosion type and the morphology of the oxide scale were examined by optical microscopy and scanning electron microscope (SEM). Corrosions products were examined with EDS/EDAX. The optical micrograph shows that as cast Fe-9Al-0,6C alloy has ferrite and pearlite microstructure. The result of Jominy test shows that these alloy non-harden able. The result of corrosion testing showed that the alloy more resistance in NaCl than in H2SO4 solution. Optical micrograph and SEM analysis indicated that corrosion form is general corrosion and there is no trend toward intergranular attack.

Keywords : Fe-Al-C alloy, conventional stainless steel, harden ability, corrosion resistance.