The result reveals that the practical secondary cooling system is not suitable and easy to cause quality defects such as internal crack.
结果表明，目前的二冷制度不甚合理，易产生内裂纹等质量缺陷。
2
Bearing parts in the process of hardening cooling by internal stress due to the formation of quenching cracks crack said.
轴承零件在淬火冷却过程中因内应力所形成的裂纹称淬火裂纹。
3
Ceramicss are not typically formed from the melt. This is because most ceramics will crack extensively (i. e. form a powder) upon cooling from the liquid state.