Abstract: The front fairing cabin casting produced by Aero-engine Technology Foundry is a very important product inn a certain type of engine. The casting is made of ZM3, belongs to casting parts Ⅱ. During the production in 2001, the high-temperature creep properties of the casting was unqualified in five consecutive batches.This event seriously affected the processing and installation of the products, resulting in huge losses.Rare earths and zirconium are two important parts in ZM3 alloy. Rare-earth metal has great influence on high temperature performance. Zirconium is mainly used for grain refinement.After repeated tests, the composition control points of Ce-rich rare earths were determined: rare-earths≥98%, Ce≥45%, 10%≤Nd ≤18 %. The research results have been reflected in the corresponding national standards, industry standards and enterprise standards.