Research of G105 Chloride Ion Stress Corrosion Cracking
At present, there are also very few regarding drill pipe's SCC research in chloride ion ambient medium, so it is specially important to definite the stress corrosion sensitivity of drill pipe to the influence under different chloride ion density and to provide the appraisal basis for the influence of the chloride ion density to drill pipe's corrosion. Applied the G105 drill pipe material to do Slow Stress Rate Testing (SSRT) and the electrochemical experiment under the different chloride ion environment, analyzed the variation of corrosion current and corrosion potential and observed the fracture. The results show that all of the tensile specimens' fracture morphologies are brittle fracture; and the stress corrosion cracking sensitivity of the material increases gradually with the addition of chloride ion concentration; the corrosion rate also tends to increase, but when the chloride concentration is 6000, the corrosion rate is up to a extreme value; the effect of chloride concentration to the cathode is much more than that to the anode, but the G105 pipe corrosion in different chloride solution is controlled differently. The stress can improve the stress corrosion cracking sensitivity of material in corrosion solution. The anti-corrosion principle of chloride ion corrosion is: to reduce adsorption of chlorine ion on the surface.
Zhengyi Jiang, Jingtao Han and Xianghua Liu
B. S. Huang et al., "Research of G105 Chloride Ion Stress Corrosion Cracking", Advanced Materials Research, Vols. 152-153, pp. 659-665, 2011