胀断MC11H连杆横向断面收缩率低的原因

Cause of low transverse percentage reduction of areashrinkage of fracture MC11H connecting rod

通过宏观观察、化学成分分析、断口分析、金相检验、扫描电镜及能谱分析等方法,分析了胀断MC11H连杆横向断面收缩率偏低的原因。结果表明:在连杆锻造过程中,锻件大头、小头端心部和横截面1/2半径处的金属沿锻件宽度方向向四周流动,导致连杆大头端分布着短条状MnS夹杂物,从而使MC11H连杆的横向断面收缩率降低。

Through macroscopic observation, chemical composition analysis, fracture analysis, metallographic inspection, scanning electron microscopy and energy spectrum analysis, the reason for low transverse percentage reduction of areashrinkage of fracture MC11 H connecting rod was analyzed. The results showed that during forging process of connecting rod, the metal at the center of big end, small end and 1/2 radius of the cross section of forging flowed around in the width direction of forging, resulting in short MnS inclusions intermittently distributed at big end of connecting rod, thereby the transverse percentage reduction of areashrinkage of MC11 H connecting rod was reduced.