一、前言各类球铁中贝氏体球铁具有最好的综合机械性能,它的强度、硬度、塑性和韧性都较好,已被用于制作凸轮轴、齿轮和链轮等要求高的零件。近年来,国内外对材料的低温性能都很重视。一般认为冲击韧性比延伸率对温度更敏感,因此,研究 First, the preface All kinds of ductile iron in bainite ductile iron has the best overall mechanical properties, its strength, hardness, ductility and toughness are better, has been used to make camshafts, gears and sprockets and other demanding Components. In recent years, both domestic and foreign attach importance to the low temperature performance of materials. It is generally considered that impact toughness is more temperature sensitive than elongation, and therefore, research