摘要
采用覆砂铁型生产6缸气缸体,发现其顶面有砂眼、夹杂物缺陷,分析认为缺陷产生的原因是:(1)射砂板漏砂,降低铸型砂层表面强度;(2)模样收缩率过大,导致型腔与砂芯间隙过大,调整砂芯位置时容易造成砂芯局部表面松散;(3)熔炼过程中产生的夹杂物和气体没有充分清除;(4)涂料质量欠佳,不能加固铸型表层。采取的改进措施是:(1)改进射砂板,减少漏砂;在铁模上增设固砂槽,改善铸型与砂芯的配合间隙;(2)选择合适的铁液保温静置时间,使气体和夹杂物充分上浮;使用覆盖剂和集渣剂以及恰当的扒渣工艺,去除铁液中的夹杂物;(3)采用自制改进的涂料。生产结果显示:缸筒顶面的夹杂物已全部消除。
6-cylinders block was produced by using resin sand-coated iron mold and it was found that there were sand inclusions and slag inclusions on the top surface of the cylinder block. It was considered by analysis,the reasons causing defects were：（1）There was sand leakage with the sand-shooting plate that decreased the strength of sand layer of the mold.（2）The shrinkage allowance of the pattern was too big that caused the matching gap between the mold cavity and the sand cores too big and thereby caused sand loosing of the local core surface when adjusting the position of cores.（3）The inclusions and gases forming during iron melting were not fully cleared out.（4）The quality of coating was not good,the coating could not strengthen the surface layer of the mold. The improving measures were：（1）Improving sand shooting plate to reduce sand leakage,setting sand-fixing grooves on the iron pattern to improve the matching gap between mold cavity and cores.（2）Choosing proper holding time of iron melt to allow the gas and inclusion fully floated upwards,using covering flux,slag collecting agent and proper slag-skimming process to eliminate the inclusions of the iron melt.（3）Using self-prepared improved coating. As the result,the inclusions occurring on the top surface of the cylinder block had been totally eliminated.
出处
《现代铸铁》
CAS
2017年第6期69-71,共3页
Modern Cast Iron
关键词
气缸体
缸体顶面
夹杂物
cylinder block
top surface of the cylinder block
inclusion
