硅量对消失模铸造高硅球墨铸铁组织和性能的影响  

Effect of Silicon Content on Microstructure and Properties of High-silicon Ductile Iron in Lost Foam Casting

作　　者：王灼 刘越 周占虎 官振兴 张雅静 WANG Zhuo;LIU Yue;ZHOU Zhanhu;GUAN Zhenxing;ZHANG Yajing(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,Liaoning China;Liaoning Ever Metal Forming Tech Co.,Ltd.,Gaizhou 115200,Liaoning China)

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110819 [2]辽宁爱维尔金属成型科技股份有限公司,辽宁盖州115200

出　　处：《铸造工程》2022年第4期31-38,共8页Foundry Engineering

摘　　要：研究了硅含量对消失模铸造高硅球墨铸铁组织和性能的影响。用光学显微镜和扫描电镜对石墨形貌及基体组织进行观察,用万能拉伸试验机和数显布氏硬度仪测量其力学性能。结果表明,采用消失模铸造工艺,浇注温度为1487℃、负压0.05 MPa、球化剂加入量1.3%制得的含硅量为2.9%~4.6%的高硅球墨铸铁基体组织为全铁素体;硅含量增加使球状石墨尺寸减小,铁素体晶粒平均尺寸减小形成细晶强化;同时由于硅固溶于铁素体中形成置换固溶体,随着硅含量的增加在铁素体晶界上产生偏析且程度越来越大,使铁素体基体产生晶格畸变,对铁素体产生显著的强化作用,因此高硅球墨铸铁的强度和硬度随着硅含量的升高而升高。当硅含量为2.92%时,球状石墨平均尺寸为35.6μm,抗拉强度为441 MPa,布氏硬度为128 HBW,伸长率为17%;当硅含量为4.59%时,球状石墨平均尺寸为26μm,抗拉强度为683 MPa,布氏硬度为186.1 HBW,伸长率为17.5%,综合力学性能较高。The effect of Silicon content on the microstructure and mechanical properties of High-Silicon Ductile Iron produced by lost foam casting(LFC)was investigated.The results show that the matrix microstructure of High-Silicon Ductile Iron with Silicon content of 2.9%~4.6%is full Ferrite under the conditions of EPC process,pouring temperature of 1487℃,negative pressure of 0.05 MPa and nodulizer addition of 1.3%,and that the size of spheroidal graphite decreases with the increase of Silicon content,As a result,the average size of Ferrite grains decreases,resulting in fine grain strengthening.Silicon dissolves in Ferrite to form a substitutional solid solution.With the increase of Silicon content,segregation occurs on the Ferrite grain boundaries to a greater extent,resulting in lattice distortion of Ferrite matrix and significant strengthening effect on Ferrite.Therefore,the strength and hardness of High-Silicon Ductile Iron increase with the increase of Silicon content.When the Silicon content is 2.92%,the average size of spheroidal graphite is 35.6μm,the tensile strength is 441 MPa,the Brinell hardness is 128 HBW,and the elongation is 17%;When the silicon content is 4.59%,the average size of spheroidal graphite is 26μm,tensile strength is 683 MPa,the Brinell hardness is 186.1 HBW,elongation is 17.5%,and the comprehensive mechanical properties are higher.

关 键 词：硅含量 消失模铸造 高硅球墨铸铁 微观组织 力学性能 

分 类 号：TG143.5[一般工业技术—材料科学与工程]