Cracking reason of a drilling tool probe pipe

Lateral cracking occurred in the probe pipe of a drilling tool. The cracking causes of the probe pipe were analyzed by means of macroscopic observation, chemical composition analysis, hardness test, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that the material of the probe pipe was austenitic stainless steel, and the chloride ion in the service environment provided a corrosion environment for its stress corrosion. The probe pipe was subjected to axial stress during drilling, and the residual stress generated during the manufacturing process provided mechanical conditions for stress corrosion cracking, which eventually led to chloride stress corrosion cracking of the probe pipe.