Influence of Cooling Rate on As Cast Microstructure of Multi-component White Cast Iron

摘要

Four kinds of multi-component white cast ironswith different combinations of carbide type were poured into furanmolds with different diameters, and cooling curves were takenusing a R thermocouple inserted at the center of each mold cavity.The microstructural components in as cast iron, such as γ dendritearm spacing (Dp), diameter (DMc) of MC carbide, lamellarspacing (γ+M2c) of M2C carbide, area fraction (Seut) of (γ + M2C)eutectic or that of both (γ + M2C) plus (y + M7 C3) eutectics, werewell related to each characteristic cooling rate, while the areafraction of MC carbide was little affected by the cooling rate. Therelations are expressed by, Dp= 25.1 Vp-0.36 (Vp=cooling rateduring precipitation of primary γ) DMc 4.4. VEM015 (VE.Mc :cooling rate during precipitation of ( γ + MC) eutectic), M2C = (1.1~2.O) .