Oscillographic Impact Toughness and Dynamic Fracture Toughnes of V-150 Drill Pipe Steel

The oscillographic impact properties and crack propagation characteristics of impact fracture at different temperatures from -60 ℃ to 25 ℃ were analyzed by comparsion through oscillographic impact experiment and observation of impact fracture morphology of V-150 drill pipe longitudinal specimens. The results indicate that the impact energy, crack propagation work and the ratio of crack extension work to impact energy of V-150 drill pipe steel decreased, but the ratio of crack to impact energy rose, with temperature decreasing. The fracture was a typical toughness fracture with dimples at normal temperature. When the temperature decreased, the fracture characteristic changed from ductile fracture to brittle fracture, and showed cleavage brittle fracture at -60 ℃.