Analysis of Cracking of Oil Drill Pipe

The key element responsible for the cracking of the oil drill pipe is the large inclusion in the continuously cast billet. This conclusion is supported by the results of NDT detection and visual inspection of the pipe body and microstructure tests with the defective sample taken from the pipe by scanning electron microscope and energy spectrometer. The crack development process is also analyzed with the steel tube plastic deformation theory, and corrective actions are accordingly put forward.