某YG8硬质合金冲裁模具在使用过程中发生早期开裂失效。通过宏观观察、硬度测试、扫描电镜及能谱分析、金相检验等方法，对冲裁模具的开裂原因进行了分析。结果表明：由于冲裁模具原材料保存不良，钨粉接触空气发生氧化，材料中产生大量脆性η相及网状裂纹，使材料的强、韧性指标急剧下降，导致冲裁模具在服役过程中无法承受工作应力，从而产生早期开裂失效。

The early cracking failure occurred to a blanking die of YG8 cemented carbide in the course of use. The cracking reasons of the blanking die were analyzed by macroscopic observation, hardness testing, scanning electron microscope and energy spectrum analysis, metallographic inspection and so on. The results show that:due to the poor preservation of the blanking die material, the tungsten powder contacted with the air and oxidized; as a result of that, there were a lot of brittle η phase and reticular cracks in the structure, and the indexes of the strength and toughness of the material drastically reduced; the blanking die couldn't bear the working stress during use, and the early cracking failure occurred.