Effect of pH on Oxygen Corrosion At Elevated Pressures

A summary study of oxygen corrosion of mild steel in brine is presented. Corrosion rates were determined for oxygen pressures ranging from atmospheric to 515 psia and over a pH range of 1 -13.5. All tests were conducted at room temperature (24 C). It is shown that corrosion rates are generally increased with increasing oxygen pressure and decreasing pH; however, when tests exceeded 6 hours duration, an accelerated corrosion developed over the pH range 8-12. An unusual filamentary type corrosion product develops and grows in the 300-500 psi oxygen pressure range in pH 12 system. The identification and proposed mechanism of growth are given. 3.4.6