缸体珩磨后缸筒麻点问题的分析与解决

Analysis and Solution of the Problem of Puncture of Cylinder After Honing

介绍了3.2 L柴油机缸体在装配过程中不镶嵌缸套,产品精加工珩磨后,在缸筒内出现大量肉眼可见的"麻点"。经解剖分析认为,"麻点"是由粗大石墨在加工过程中,从基体上脱落而形成的石墨脱落孔洞。通过调整熔炼工艺,采用铁液过热的方式,消除或减弱粗大石墨的遗传性,并在出铁包中按照1:1的比例使用ZY-HTL-10型孕育剂和75SiFe孕育剂,解决了产品缸筒位置石墨粗大的问题,消除了缸筒珩磨后出现的"麻点"情况。

The problem of 3.2L diesel engine cylinder not embedded with the cylinder liner during the assembly process and a large number of pitting points visible to the naked eye appear in the cylinder after finishing and honed were introduced. According to the analysis on internal surface,the pitting point was a hole formed by the coarse graphite falling off from the substrate during the processing. By adjusting the smelting process and using iron liquid overheating,the heritability of the coarse graphite was eliminated or attenuated,and the ZY-HTL-10 type inoculant and 75SiFe inoculant were used in the ratio of 1:1 in the iron package. The problem of coarse graphite at the cylinder position was settled. And the pitting occurs after the cylinder honed was eliminated.