高镍奥氏体球墨铸铁显微缩松与碳化物的研究  

Study on Porosity and Carbide of High Ni Austenitic Ductile Iron

作　　者：程凤军[1] 罗广思[1] 潘安霞[1] 

机构地区：[1]常州轻工职业技术学院,江苏常州213164

出　　处：《铸造》2017年第3期282-285,293,共5页Foundry

摘　　要：高镍奥氏体球墨铸铁的显微缩松和碳化物对铸件的使用性能有较大影响。分析了显微缩松产生的原因和防止措施。加强顺序凝固可以减小或消除显微缩松,但受发达奥氏体枝晶的影响,仍存在产生显微缩松的倾向;强化孕育是防止显微缩松产生的另一个有效措施。碳化物形态分布分析表明:铸态碳化物呈块状和条状分布于奥氏体晶界,在冷热交变载荷下易产生热疲劳裂纹;热处理后的碳化物呈细小弥散分布,材料的综合性能有所提高,有利于防止热疲劳裂纹的产生。Porosity and carbides of high nickel austenitic ductile iron have a great influence on the service performance of the casting. The causes of micro-porosity and preventive measures were analyzed. Enhanced sequence solidification can reduce or eliminate porosity, but for the development of austenite dendrites, there still exist porosity tend. Strengthening inoculation is another effective measure to prevent porosity. The analysis results of the distribution of carbides show that the as-cast carbides were distributed in the austenite grain boundaries and in massive and strip form, which was easy to produce fatigue crack under the alternating heat and cold load. After heat treatment, the carbides show a fine dispersion distribution, the comprehensive properties of the material are improved, and the morphology and distribution of the carbides are beneficial to preventing the fatigue crack.

关 键 词：奥氏体球墨铸铁 奥氏体枝晶 显微缩松 碳化物 

分 类 号：TG255[金属学及工艺—铸造]