冶金缺陷 meaning in English

metallurgical defects
metallurgical imperfection

The microstructure of coat do not take place obvious change as increased induction current and decreased melt time
重熔层组织致密，未发现未熔合及夹渣等冶金缺陷。
The resuits show that metallurgical deject is the main reason leading to early formation of fatigue crack under normal working stress
认为，该曲轴材料的冶金缺陷是导致疲劳裂纹在正常工作应力下过早形成的原因。