气缸套开裂原因分析

Analysis on Cause of Cylinder Jacket Cracking

气缸套在机械加工过程中发现有纵向裂纹。对有裂纹的气缸套进行了宏观检查、化学成分分析、硬度检测和金相检验。结果表明:气缸套有大量游离碳化物,局部区域有疏松,还有较多的D、E型过冷石墨。正是这种不正常的显微组织导致了缸套脆性开裂。

The cylinder jacket was found to have longitudinal crack during the machining.Macro-check,chemical composition analysis,hardness measurements and metallographic test were carried out for the cracked cylinder jacket.The results showed that the cylinder jacket exhibited a large amount of free carbides,porosities in local area,and more E-graphite and D-graphite.It was these abnormal structures that resulted in brittle cracking of the cylinder jacket.