Electrochemical ZRA test cells for determination of galvanic corrosion rates in atmospheric environments
AssigneeThe Government of the United States of America, as represented by the Secretary of the Navy
InventorsCarlos M. Hangarter, Steven A. Policastro
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Abstract
The invention is directed to a real-time, zero resistance ammeter (ZRA) galvanic corrosion detection instrument that is adapted to measure corrosion under atmospheric conditions. The instrument may be used in accordance with methods for selecting materials based on environmental conditions and electrolyte chemistries. The electrochemical ZRA test cell of the invention may further be used to determine galvanic corrosion susceptibility, aid in forecasting corrosion, and determine the extent of corrosion based on environmental factors.
Claims23
A zero resistance ammeter (ZRA) galvanic atmospheric corrosion kinetics (GACK) detection instrument, comprising:
- an anode;
- a cathode;
- an electrolyte provided at the anode;
- an electrolyte provided at the cathode;
- wherein the electrolyte at the anode and the electrolyte at the cathode are provided as droplets or thin films;
- a salt bridge electrolytically-connecting the electrolyte at the anode with the electrolyte at the cathode;
- and
- a ZRA electrically-connecting the anode and the cathode.
A method for measuring galvanic atmospheric corrosion current density, comprising:
- providing an anode, a cathode, and separated electrolytes at the anode and cathode;
- providing a salt bridge in which a first end of the salt bridge contacts the electrolyte at the anode, and a second end of the salt bridge contacts the electrolyte at the cathode, forming a separated electrolytes galvanic couple;
- providing a zero resistance ammeter that is electrically connected to the anode and cathode;
- measuring corrosion current density of the separated analytes galvanic couple using the zero resistance ammeter;
- and
- comparing the corrosion current density to an intersection point of polarization scans obtained by a zero resistance ammeter connected to the anode and cathode in the absence of the separated electrolytes,
- wherein when the corrosion current density of the separated electrolytes galvanic couple is higher than the intersection point of the polarization scans, the presence of the separated electrolytes causes accelerated corrosion of the anode as compared to corrosion of the anode in the absence of the electrolyte.
A zero resistance ammeter (ZRA) galvanic atmospheric corrosion kinetics (GACK) detection instrument, comprising:
- an anode;
- a cathode;
- an electrolyte provided at the anode;
- an electrolyte provided at the cathode;
- wherein less than an entire surface of the anode or the cathode is exposed to the electrolyte at the anode or cathode;
- a salt bridge electrolytically-connecting the electrolyte at the anode with the electrolyte at the cathode;
- and
- a ZRA electrically-connecting the anode and the cathode.
A zero resistance ammeter (ZRA) galvanic atmospheric corrosion kinetics (GACK) detection instrument, comprising:
- an anode;
- a cathode;
- an electrolyte provided at the anode;
- an electrolyte provided at the cathode;
- a micro-pipette salt bridge electrolytically-connecting the electrolyte at the anode with the electrolyte at the cathode;
- and
- a ZRA electrically-connecting the anode and the cathode.
Dependencies are inferred from the claim text.