An Influence of Nodularity and Graphite Count on Ultrasonic Speed in Compacted Graphite Iron

摘要

The environmental regulations have been enacted to get stronger. Thus, engine designers are forced tornseek stronger materials than conventional materials for engine cylinder block. Nowadays, Compacted Graphite Iron (CGI)rnhas been widely substituted for Grey Cast Iron in engine cylinder block, since CGI has the advantage of strength comparedrnto Grey Cast Iron, and the advantages of thermal conductivity and fluidity compared to Ductile Cast Iron.rnThe quality assurance of mass production products became one of important issues to engine materials. Thus, somernnondestructive inspections are widely used for the mass productions of Ductile Cast Iron. But the nondestructive qualityrninspection methods of CGI alloys were rarely reported. So in this study, ultrasonic velocity was investigated related withrnmicrostructure of some CGI alloys, for the purpose of nondestructive inspection methodology.