The perforation performance is an important index of oil - layer casing representing the resistance to initial brittlecrack growth.
射孔性能是油层套管很重要的一项指标，它代表着油层套管抵抗裂纹脆性扩展的能力。
2
The existence of grey spot may cause brittlecrack of the joint, therefore, controlling grey spot occupy a decisive position to ensure the quality of rail resistance welding.
灰斑的存在易导致接头的脆性断裂。因此，控制灰斑对保证钢轨接触焊质量举足轻重。
3
The results show that the cracking of the tap valve is brittlecrack, which is due to overheat to cause the formation of defects, such as coarse grains, Widmanstatten structure and porosity.