Effect of cerium modification on microstructure and properties of hypereutectic high chromium cast iron

摘要

The effect of cerium modification on the microstructure and properties of hypereutectic high chromium cast iron primarily containing 4.0 wt% C and 20.0 wt% Cr was studied by means of optical microscopy, transmission electron microscope, scanning electron microscope, and energy dispersive X-ray spectro-metry. The primary M_7C_3 carbides were refined obviously when cerium was added in the melt. Ce_2S_3 was found in the primary M_7C_3 carbides and acted as the heterogeneous substrate of M_7C_3 carbides. The impact toughness of the specimen modified with 0.5 wt% cerium increased by 50% compared with the specimen without cerium modification. The hardness of the alloy modified with cerium increased slightly compared with the specimen without cerium modification.