正常工艺生产的输油管（不含穿透性缺陷）具有足够的断裂韧性值，但在水压试验时，却全部发生了爆裂．分析表明破坏过程是管中非穿透缺陷由于周围材料流变而变成穿透裂纹，使管子失效，所以失效抗力仅取决于管材及焊缝强度．当穿透裂纹撕裂到临界尺寸时，管子爆裂才发生．仅在这时，断裂韧性和强度才对爆裂应力有影响．因为用在输送线上管子的初始缺陷是非穿透性的，所以提高材料强度减少焊缝缺陷是增加失效应力的有效措施．文中也给出了破坏应力与允许裂纹尺寸的关系曲线 The normal production of the pipeline (without penetration defects) has sufficient fracture toughness value, but in the hydraulic test, but all burst occurred. The analysis shows that the failure process is that the non-penetrating defects in the tube become penetrating cracks due to the rheological changes of the surrounding materials, thus invalidating the tube. Therefore, the failure resistance depends only on the strength of the pipe and the weld. When the penetration cracked to a critical size, the tube burst occurred. Only then does fracture toughness and strength affect burst stress. Since the initial defect of the pipe used on the transfer line is non-penetrating, increasing the material strength and reducing weld defects are effective measures to increase the failure stress. The paper also gives the relationship between the failure stress and the allowable crack size