Corrosion resistance of steel for coiled tubing units

The gravimetric method was used to determine the corrosion rate of a pipe for coiled tubing. Scanning electron and optical microscopy were study microstructure nature damages. It has been found that processes different occurred in studied systems “metal – environment”, particular, acid solutions, caused by hydrochloric ambient temperature 70°?. In solution with smaller content, along general corrosion, there is significant localization process (deep damage formed: macro pitting ulcers). observed HCl (13 mass %), which destroys walls after 576 h exposure. neutral solutions intensity comparison acidic environments, even taking into account factor. surface-active substances or petroleum products are present form barrier films on steel surface, prevent access corrosive components from environment surface material, especially during short exposure time. With increase at elevated temperatures, break down undergoes corrosion.