摘要
针对显微缩松是否影响铁素体基球墨铸铁低温韧性的问题,采用改变冒口颈直径的办法对铸锭内显微缩松进行调控。用Axiovert200MAT金相显微镜和MLA 250(FEI Quanta)扫描电子显微镜观察金相组织和显微缩松,用Nano Measurer 1.2软件测量石墨球的个数及直径。结果表明,金属型铸造球墨铸铁时,合适的冒口颈直径可使三角形显微缩松数量减少、尺寸减小,同时促使三角形显微缩松向多边形或蠕虫状转变。对于纯铁素体基球墨铸铁,当球化率与石墨球数量达到一定程度后,显微缩松转变成影响球墨铸铁超低温冲击韧性的关键因素。
Microshrinkage affects the low temperature toughness of ferritic ductile iron. In order to solve the problem,cast iron ingots were cast by using different riser neck diameters in the work. The microstructure and microshrinkage were observed using Axiovert 200 MAT metallographic microscope and MLA 250 FEI Quanta scanning electron microscope;graphite nodule diameter and count were measured by software of Nano measurer 1.2. The results suggest that the suitable diameter of riser neck could reduce the triangle microshrinkage and its size in matrix, and promote the transformation of microshrinkage shape from the triangle to polygon or worm-like. For the pure ferritic ductile iron, the microshrinkage became the key factor affecting the ultra low temperature toughness when the spheroidization rate and graphite nodule count reached a certain level.
作者
侯超
任为
宋佳健
孙海清
常国威
HOU Chao;REN Wei;SONG Jia-jian;SUN Hai-qing;CHANG Guo-wei(School of Materials Science and Engineering,Liaoning University of Technology,Jinzhou121001,Liaoning,China;Jinzhou JT Railway Machinery Co.,Ltd,Jinzhou121116,Liaoning,China)
出处
《铸造》
CAS
北大核心
2019年第2期123-127,共5页
Foundry
基金
辽宁省重点研发计划项目(2017106019)
关键词
铁素体球墨铸铁
显微缩松
低温韧性
ferrite ductile iron
microshrinkage
low temperature toughness
