Abstract
The electrochemical behavior of A516 grade 70 (UNS K02700) carbon steel with a ferrite-pearlite structure in acidic chloride (Cl-) solutions containing hydrogen sulfide (H2S) at 25°C was investigated by electrochemical impedance spectroscopy (EIS). Results showed the impedance of A516 steel increased in an acidic Cl- solution with H2S (compared to a solution without H2S) at the open-circuit potential (OCP). The corrosion process for A516 steel in the H2S-containing solution was in two stages. Polarization resistance (Rp) initially increased with time for immersion up to ∼ 10 h but then decreased gradually. In the early stage, the impedance was characterized by one large semicircle in the Nyquist plot that increased with time for immersion up to 3 h. In the later stage, precipitation of a sulfide film modified the surface properties and led to variation in EIS data through a capacitive effect in the low-frequency region.
| Original language | English |
|---|---|
| Pages (from-to) | 708-713 |
| Number of pages | 6 |
| Journal | Corrosion |
| Volume | 52 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 1996 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Chemical Engineering
- General Materials Science