Effects of Mo additions on the solidification of high chromium cast iron

High chromium white cast irons present high resistance to abrasive wear, be ing employed fundamentally in industrial branches that manipulate hard raw materials, such as the mining industry. Eutectic and hypoeutectic alloys co ntaining increasing contents of molybdenum (0-2 wt%) were cast and used for the investigation of the effect of Mo and of the cooling rate on the coars ening of carbides, The experimental results were obtained by DTA experiment s and by casting in special moulds specially designed to obtain directional ly solidified columnar grains. Molybdenum additions results in increased eu tectic cell diameter and increased carbide particle spacing. Molybdenum dec reases both the austenite primary solidification temperature and the starti ng temperature for the univariant eutectic L --> gamma + M7C3, but the over all effect results in increased solidification intervals both in the austen ite field and in the eutectic field.