Effects of Si and Mn on Microstructure and Mechanical Properties of Bainite Ductile Iron by Step Austempering in Room-Temperature Machine Oil

In this work,the effects of Si and Mn on the microstructure and mechanical properties of the bainite ductile iron by step austempering in the room-temperature machine oil have been studied.The experiment results show that induced phase transformation in the bainite ductile iron can be brought out by Si in 3.3%-3.8%,and the structure with good mechanical properties has been obtained;Mn can increase the hardness and reduce the impact toughness of the bainite ductile iron.Reasonable Si and Mn content can improve mechanical properties of the bainite ductile cast iron.