Pengembangan Metoda Modifikasi Struktur Mikro Besi Cor Kelabu Dengan Pemanasan Cetakan

Abstract

Process austempering is process started by heating material until formed austenite phase then in quench at media saltbath which has been heated to martensite temperature start, then arrested until full orthogonal transformation austenite then made cool at space temperature. It’s purpose improve mechanical properties a material. Weakness from this process that is costing money expensive. For the purpose modification process austemper we would change by the way of moulding direct at metal mold which outside mold in holding up with saltbath. The aim of this research is to know the effect of using saltbath media to substitute sand media. The variation treatments were saltbath casting-mould which heated to the point of 300oC and hold out in 300oC until 2 hours, and saltbath casting mould which heated to the point of 300oC then decreased its temperature until reach environmental temperature. The effect of saltbath media for casting product will be knew using hardness testing and micro structure, and than, that product compared with sand media casting’s product. From the tests and analyzing, From this assaying known sand printed material gray cast iron to have average of hardness 204.74 BHN while at printed material cast iron saltbath average of hardness 377 BHN happened at specimen B, at specimen C average of hardness 422.38 BHN.have been known that the variation of saltbath media casting’s product were better than sand media casting’s product. Key word : Austempering, Gray iron, Saltbath, Hardness Testing, Micrography Testing.