【摘要】 作者通过熔炼热力学和动力学分析,探索出在感应电炉中稳定地大量增碳、大量投用废钢而制得合成铸铁的途径,并已在两个工厂用于生产。采用这种方法生产出的合成铸铁,较之相同熔炼条件下生产的普通灰铸铁具有以下特点和优点:石墨短小1~2级并增厚,纯头石墨增多并呈A型分布;基体98%以上为珠光体,共晶团细小1~2级;抗拉强度提高1~2级,白口倾向和壁厚敏感性显著降低,综合性能稳定;共晶度为0．95时,强度接近HT25—47,共晶度0.85时,4.5~7mm薄壁件不出现白口且切削性能良好;试生产中铸件的白口、缩松等废品大幅度下降;熔炼过程中,一般不增加电耗;随废钢配比的增加,铁水的成本可降低10—40%。文中着重探讨了大量增碳的途径和配加废钢、变质剂对性能的影响。更多还原

【Abstract】 Abstract Through analysis of smelting thermodynamics and kinetics,authors have found out amethod of making synthetical casting iron by using a large proportion of scrap steel and carburizing it greatly and steadily. This method has been adopted in practical production in two factories.Compared with common gray iron produced in the same smelting condition, the synthetical cast iron produced by this method has following characters and advantages: the size of graphite is reduced by 1? grade and it becomes thicker,more graphite is of blunt form and its distribution type is AI the matrix is mainly of pearlite phase (more than 98%), and the eutectic colony size is reduced by 1? gradei the tensile strength is increaced by 1? grade, while the tendency of appearing white iron and the sensitivity of thickness is greatly lowed,and the comprehensive properties are steady.when the structure of iron has 95% eutectic phase, the strength is near that of HT25?7. when the untectic dgree is 0.85, there will not appear white iron in a thin walled workpiece of thickness between 4.5~7mm,and the cast iron is easy for machining.In trial productionthe percentage of waste casting piece caused by white iron and contraction cavity is g-reatly reduced .There is no need for more electricity consume in smelting processiand with the increace of proportion of steel scrap, the cost of molten iron can be reduced by 10~40%.In this paper,authors discussed with emphasis on the way to carburize the iron and the effects of adding steel scrap and modifier on the properties.更多还原