低碳球墨铸铁的性能与球化研究

【作者】 邢泽炳；

【导师】 舒信福；

【作者基本信息】 昆明理工大学 ， 材料加工工程， 2002， 硕士

【摘要】 本文对低碳球铁的组织、性能、处理工艺及球化进行了实验研究，分别考察C％=1.2％、Si％=1.8％；C％=1.4％、Si％=2.0％；C％=1.8％、Si％=2.2％；C％=2.0％、Si％=2.4％四组成分的低碳铁水在系列化SX变质剂的作用下形成的不同组织与表现出的力学性能，以及它们之间的关系。分析了低碳铁水中的元素与孕育剂中的元素对低碳球铁球化与性能的影响。结果表明：经SX变质剂处理后的低碳铁水可以获得细小、分布较广的石墨球，低碳球铁的综合性能不低于传统球铁，在铸态下就可以达到QT700-2的水平。但成本却大为降低。 低碳球铁在铸态下的抗拉强度可达750MPa，冲击韧性可达20J／cm~2，其中石墨球直径在5～20μm，基体以珠光体为主，有少量的铁素体与渗碳体。对低碳球铁的强化与韧化做了初步的分析研究，认为低碳球铁的韧化处理具有很重要的现实意义。在扫描电镜(SEM)与透射电镜(TEM)上观察石墨球，与传统石墨球相比低碳球铁的石墨球呈细小点状分布，球墨中心聚集有较多的球化元素而在边缘处分布有反球化元素。石墨球中心存在有氧化 【摘要 一 物、硫化物以及氮化物等组成的复杂的化合物，经分析 认为它们是球状石墨形核的有效核心。最后提出进一步 改善低碳球铁性能的建议。更多还原

【Abstract】 In this paper,the structure, mechanic properties, treat technology and spheroidising of low carbon ductile cast iron are studied,The structure and different properties of four kind of low carbon ductile cast iron, including C%=1.2%, Si%=1.8%, C%=1.4%, Si%=2.0%, C%=1.8%, Si%=2.2%, C%=2.0%, Si%=2.4%,are analysised.The influence of elements in low carbon ductile cast iron and in Sx inoculant are analisised.As a result there are many much small graphite nodule in low carbon ductile cast iron which are inoculated by SX inoculantThe comprehensive mechanic properties of low carbon ductile cast iron are not less than the traditional spheroidal graphite iron.Their strength of extension can reach the level of QT700-2,but the cost of low carbon ductile cast iron is much low.The strength of extension of low carbon ductile cast iron can reach 750MPa in casting state, the impact ductility can reach 20J/cm2.The diameter of graphite nodule is 5-20 (am,the base body is consisted of pearlite -. a little ferrite and cementite, through the analysis of the strengther and ductiler ,we draw the conclusion that this is very important in reality, observing the graphite nodule in SEM and TEM, there are many spheroiding element and anti-spheroiding elements in the core and edge of graphite nodule, they form the oxides sulphide and nitride .we draw the conclusion that they may be the core of graphite nodule. At last we make an advocate to improve the properties of low carbon ductile cast iron.更多还原