Improvement of microstructure and properties of heavy-duty diesel cylinder head by optimizing chemical compositions

摘要

For the newly developed full size heavy-duty diesel engine, an advanced cylinder head material with high performance has been required to meet severe service environments. The gray cast iron with 25kgf/mm{sup}2 tensile strength has been generally used for cylinder head. With the size increase, however; the casting defects such as shrinkage, ferrite segregation, coarse graphite became significant problems. These defects are mainly from improper casting parameters combined with poor chemical composition of melts. Our study mainly focused on optimization of chemical composition and ensure improved mechanical properties and prolonged service life.