前言球墨铸铁材料有较高的强度、刚度,相当的塑性和动载性能,而且有耐磨、耐热、吸震和工作噪音低等优点。国外已被用于制造汽车齿轮等零件。我国根据资源特点发展的稀土镁球墨铸铁居世界先进水平,目前已用于制造柴油机曲轴、连杆、凸轮轴及汽车、拖拉机减速齿轮,螺旋伞齿轮等机器零件。但是,到目前为止,球铁仅限于铸造工件尺寸精度不够理想,而且有疏松、缩孔、夹 Foreword Ductile iron materials have high strength, stiffness, considerable plasticity and dynamic load performance, but also has the advantages of wear resistance, heat resistance, shock absorption and low working noise. Foreign countries have been used to manufacture automotive gear and other parts. Our country according to the characteristics of resource development of rare earth magnesium nodular cast iron in the world advanced level, has been used to manufacture diesel engine crankshaft, connecting rod, camshaft and automobile, tractor reducer, spiral bevel gear and other machine parts. However, so far, ductile iron is limited to the ideal dimensional accuracy of the cast workpiece, but also loose, shrinkage, folder