The Ion Passing Selectivity of CO_2 Corrosion Scale on N80 Tube Steel

摘要

In the simulating high temperature and high pressure oilfield environment containing CO_2, the structure characteristics and ion passing selectivity of corrosion scale were experimentally researched for conventional N80 steel and 4 percent Cr containing N80 steel. The results shown that the iron carbonate scale formed on conventional N80 steel has cation passing selectivity, so that the protection properties of the scale is relatively poor for metallic matrix material, and the scale relatively easily enhance the formation of pitting. The amorphous compound Cr(OH)_3 scale formed on 4 percent Cr containing N80 steel has anion passing selectivity, it is able to remarkably reduce corrosion rate and prevent the formation of pitting.