000 02231nab a2200193 4500
005 20260520000949.0
008 260224s2010 xxu
245 0 0 _aHigh-temperature electrochemical sensor for online corrosion monitoring
260 _a
_b
_csep. 2010
270 _a13/09/2010 ; 13/09/2010
300 _a8 p. ; 095002
520 _aTranscripción del resumen del autor. Electrochemical sensors incorporating diamond-like carbon (DLC)-coated electrodes are effective tools for online, real-time corrosion monitoring at high temperatures. A vacuum-based chemical vapor deposition process was used to deposit a DLC thinfilm coating on the surface of the sensing electrodes. The chemical inertness of the DLC coating on the sensing electrodes produced a crevice-free electrode that can be used at temperatures above 100°C. In this paper, we present the coating deposition process for sensor electrodes and fabrication of coupled multielectrode array sensors (CMAS) for high-temperature, high-pressure applications. Probes were fabricated using uncoated and DLC-coated Alloy 22 (Ni-22Cr-13Mo-3Fe-3W [UNS N06022]) and titanium Grade 7 (Ti-0.2Pd [UNS R52400]) electrodes. The Alloy 22 probes were tested in high-temperature, high-pressure conditions in a pH 10 caustic solution. The measured nonuniform corrosion rate using the Alloy 22 probe with the DLC-coated electrodes was approximately 2 µm/y. The titanium Grade 7 probes were tested in a dilute sodium chloride (NaCl) solution saturated with hydrogen sulfide-car-bon dioxide (H2S-CO2) at high pressures in the temperature range from 39°C to 81°C and in a saturated solution containing sodium chloride-sodium nitrate-potassium nitrate (NaCl-NaNO3-KNO3) at 150°C. The stabilized localized corrosion rates for probes with or without the DLC coating were less than 1 µm/y in the H2S-CO2 environment, and less than 0.03 µm/y in the NaCl-NaNO3-KNO3 salt mixture at 150°C. The test results indicate that titanium Grade 7 is not subject to crevice corrosion under the testing conditions.
581 _a9
773 0 _tCorrosion
_g66
942 _cARTICULO
100 1 _aChiang, K.T.
_946836
100 1 _aYang, L.
_939177
999 _c176895
_d176895