铸态铁素体低碳球墨铸铁的研究

A study on as cast ferritic low carbon ductile iron

对铸态铁素体低碳球墨铸铁进行了研究。试验中所选择低碳球墨铸铁的化学成分为:1.2%～2.2%C,2.8%Si,<0.4%Mn,<0.05%P,<0.04%S。铁液采用无芯感应电炉熔炼后,铁液的出炉温度控制在1480～1550℃之间,经过主要由某些公认的反球化元素组成的Sx变质剂进行一次性变质处理。本文分析了铁液的化学成分、变质剂的种类和加入量对铸态铁素体低碳球墨铸铁形成的影响。试验的结果表明:当C1.2%～1.8%,Sx1变质剂的加入量为0.8%或1.0%,可以得到球状石墨+珠光体+少量铁素体组织,Sx1加入量为1.2%,基体中无球状石墨,而且随着含碳量和变质加入量的提高铁素体数量基本不变。当C2.0%～2.2%,Sx1和Sx2变质剂都不能使石墨球化,Sx3变质剂加入量为0.8%,石墨被部分球化;Sx3加入量为1.2%,基体中无球状石墨,Sx3入量为1.0%,可以得到球化良好,铁素体数量大于85%和少量珠光体组织的低碳球墨铸铁,其机械性能主要为:σb≈400MPa、δ≈15%、αk≈22J/cm2,HB≈200。

As cast ferritic low carbon ductile iron has been studied ,with chemical composition as 1.2～2.2%C, 2.8%Si, 〈0.4%Mn, 〈0.05% P, 〈0.04% S.Mehed by coreless induction furnace molten iron was treated only once by Sx inoculator mainly consisting of anti-spheroiding chemical elements in common,slag reheating temperature （SRT）was controlled from 1480 to 1550＇12.How the quantity of inculator Sx effected has also been studied.It has shown that spherical graphite and pearlitic and little ferritic matrix could be got when the chemical composition was C 1.2～1.8% and the quality of Sxl inoculator 0.8% or 1.0%, the graphite was abnormal when the quality of inoculator 1.2% ,and the ferritic quality was not changed with the increase of chemical element Cand the quality of Sxl.when the chemical element C was 2.0% to 2.2% ,both inoculator Sxl and Sx2 couldn;t make the graphite spherical,the quality of Sx3 was 0.8%, not all the graphite was spherical, the quality of Sx3 was 1.2, all the graphite was abnormal. As_cast ferritic low carbon ductile iron in which the quality of ferrite was more than 85 percent and less pearlite could be got when the quantity of Sx3 inculator was 1.0%, with mechanical properties ：σb≈400MPa、δ≈15%、αk≈22J/cm^2,HB≈200.