Hollow specimen test Knee point

This video captures the in-situ hollow specimen test on X60 pipeline steel under 300 psi hydrogen pressure. At the knee, it can be observed that the pressure inside the specimen drops to zero, indicating that hydrogen has escaped from the specimen due to a crack forming from the inner to the outer surface.本视频记录了在300磅力氢气压力下对X60管线钢现场空心试样的测试。在试样拐角处，可观察到试样内部的压力降至零，这表明由于从内表面至外表面形成裂纹，氢气已从试样中逸出。