Interpretation of ISO 945-4:Microstructure of Cast Irons-Part 4:Test Method for Evaluating Nodularity in Spheroidal Graphite Cast Irons
Author of the article:WANG Zehua;ZHANG Xin;QIAN Kuncai;CHEN Kaimin;ZHU Jiahui;ZHANG Yin
Author's Workplace：School of Mechanics and Materials,Hohai University,Nanjing 211100,China;CRRC Qishuyan Institute Co.,Ltd.,Changzhou 213011,China;National Technical Committee on Foundry Standardization,Shenyang 110022,China
Key Words：spheriodal graphite cast iron spheroidization rate standardization
Abstract：Nodular cast iron was an important engineering materials,and the spheroidization rate is the key index to evaluate the quality of nodular cast iron.The definition of spheroidization of nodular cast iron and its evaluation methods in the main standards at home and abroad were reviewed."ISO 945-4 Microstructure of cast iron,Method for evaluating nodular rate of nodular cast iron"was an international standard that our country takes the lead in setting,the standard provides for the evaluation of spheroidization of nodular cast iron by visual and image methods.The main contents of ISO 945-4:2019 were introduced,including the standard terminology and name interpretation,sample preparation,evaluation method,inspection result expression,etc.,especially the definition and determination method of spherical graphite particle,the definition and determination method of spheroidization rate,and the determination of critical value related to evaluation of spheroidization rate.The revision of the definition of graphite particle number per unit area of nodular cast iron and the evaluation and representation of graphite particle number per unit area of nodular cast iron were also introduced.
