低镧镁硅铁蠕化剂的蠕化作用特性研究  

Study on Characteristics of Vermiculation Effect of Low Lanthanum Content Magnesium Ferrosilicon Vermicularizing Agent

作　　者：徐锦锋[1] 梁敬凡 邱汉泉 蒲震 孟卫如 XU Jin-feng;LIANG Jing-fan;QIU Han-quan;PU Zhen;MENG Wei-ru(School of Materials Science and Engineering,Xi＇an University of Technology,Xi＇an 710048,Shaanxi,China;Shandong Machinery Design and Research Academy,Jinan 250031,Shandong,China;Shaanxi Zhongyou Special Alloy Technology Co.,Ltd.,Xi＇an 710116,Shaanxi,China)

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]山东省机械设计研究院,山东济南250000 [3]陕西众友特种合金科技有限公司,陕西西安710116

出　　处：《铸造》2018年第9期772-777,共6页Foundry

摘　　要：采用自制低镧镁硅铁蠕化剂处理铁液,探索了蠕化剂加入量对蠕墨铸铁微观组织和力学性能的作用规律。结果表明,低镧镁硅铁蠕化剂具有较宽的适宜加入量范围,当原铁液温度为1 460℃、含硫量在0.017%～0.018%时,使用质量分数0.4%～0.9%的蠕化剂进行蠕化处理,可获得蠕化率在50%～80%范围的蠕墨铸铁材质;相应地,蠕化元素与硫元素之间的平衡浓度(质量分数)分别为Mg_残=0.011%～0.018%、La_残=0.007%～0.009%和S_残=0.013%～0.015%。铸铁中由片状石墨向蠕虫状石墨发生转变所需的蠕化剂临界加入量范围很窄,在0.35%～0.4%之间,其上限对应的蠕化率达80%。当蠕化剂加入量大于0.4%时,随着蠕化剂加入量增多,蠕化率趋于减小,球墨数量增多,珠光体数量趋于上升,蠕铁的抗拉强度、伸长率及硬度明显增大。In this paper, molten iron was treated by using self-made low lantbanide content magnesium ferrosilicon vermicularizing agent, and the effects of the addition amount of the vermicularizing agent on the microstructure and mechanical properties of the vermicular graphite cast iron were researched. The results indicate that the proper addition amount range of the vermicularizing agent is wide. When the temperature of primary iron liquid is 1 460℃ and the sulphur content is 0.017%-0.018%, the vermicular graphite cast iron with a vermicularity of 50%-80% can be produced using 0.4%-0.9% （mass fraction） addition amount of the vermicularizing agent. Accordingly, the equilibrium concentrations among residual magnesium, lanthanum and sulphur in the vermicular graphite cast iron are 0.011%-0.018%, 0.007%-0.009% and 0.013%-0.015%, respectively. In addition, the critical addition amount of the vermicularizing agent which promotes the transformation from flake graphite to vermicular graphite in the cast iron is in a narrow range of 0.35%-0.4%. The vermicularity is up to 80% for the upper limit of this narrow range. When the addition amount of vermicularizing agent exceeds 0.4%, the vermicularity decreases with the increase of vermicularizing agent, while the number of nodular graphite, the quantity ofpearlite and the mechanical properties of the alloy increase.

关 键 词：蠕墨铸铁 蠕化剂 蠕化处理 

分 类 号：TG143.49[一般工业技术—材料科学与工程]