球墨铸铁缸盖黑斑产生的原因与消除  

Causes and Elimination of Black Spots Defects on the Surface of Nodular Cast Iron Cylinder Head

作　　者：高博 严江波 王斌 曹刚 马玉亮 贺英姿 杨军军 GAO Bo;YAN Jiangbo;WANG Bin;CAO Gang;MA Yuliang;HE Yingzi;YANG Junjun(l.The Navy Military Representative Office in Xingping Region,Xingping 713105,China;Shaanxi Diesel Engine Heavy Industry Co.,Ltd.,Xingping 713105,China)

机构地区：[1]海军驻兴平地区军事代表室,陕西兴平713105 [2]陕西柴油机重工有限公司,陕西兴平713105

出　　处：《铸造技术》2021年第11期958-960,共3页Foundry Technology

摘　　要：某型柴油机球墨铸铁缸盖材质为QT500-7,精加工后上表面局部出现“麻点”现象,尤其缸盖上面靠近铸型、砂芯边缘部位较多,造成缸盖批量报废。通过对缺陷部位进行金相分析和电镜扫描分析,找出了缺陷产生的原因,编制了合适的熔炼工艺。结果表明,控制铁液碳硅当量,降低球化剂、孕育剂加入量,提高浇注温度,可以消除了表面“麻点”缺陷。The nodular cast iron cylinder head of a diesel engine was made of QT500-7.After finish machining,"black spots"appear on the upper machined surface,especially on the cylinder head,there were many parts near the edge of casting and sand core,resulting in the batch scrapping of the cylinder head.Through metallographic analysis and scanning electron microscope analysis,the causes of defects were found out and the proper smelting process was worked out.The results show that the surface pitting defects can be eliminated by controlling the carbon silicon equivalent of liquid iron,reducing the amount of spheroidizing agent and inoculating agent,and increasing the pouring temperature.

关 键 词：缸盖 麻点缺陷 碳当量 

分 类 号：TG255[金属学及工艺—铸造] TG245