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 |
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Pages (from-to) | 708-713 |
Number of pages | 6 |
Journal | Corrosion |
Volume | 52 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1996 Jan 1 |
All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Chemical Engineering(all)
- Materials Science(all)