دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

the ratio of the mass loss of actual corrosion of an anode to the theoretical corrosion mass loss calculated from the quantity of electricity that has passed between the anode and the cathode using Faraday’s law (from NACE).

a type of corrosion found when dissimilar metals are joined. One part becomes the cathode and the other the anode where accelerated corrosion may be seen.

n: 1. one of two electrodes in an electrolytic cell, represented as the positive terminal of a cell. 2. in cathodic protection systems, the protected structure that is representative of the cathode and is protected by having a conventional current flow from an anode to the structure through the electrolyte.

the negative site of a corrosion cell. Reduction reactions are typical.

n: a means of preventing the destructive electrochemical process of corrosion of a metal object by using it as the cathode of a cell with a sacrificial anode. Current at least equal to that caused by the corrosive action is directed toward the object, offsetting its electrical potential.

impressed current that offsets the current produced in a corrosion cell and reduces corrosion.

n: a positively charged ion;the ion in an electrolysed solution that migrates to the cathode. See ion. Compare anion.

n: See ion.

an ion with a positive charge.

n: 1. an electronic device that resbicts current flow chiefly in one direction. 2. a radio tube that contains an anode and a cathode.

different metals that may form an anode-cathode pair in corrosion cell conditions.

n: an electrochemical process by which metal settles out of an electrolyte that contains the metals ions and is then deposited at the cathode of the cell. electrodynamic brake n: a device mounted on the end of the drawworks shaft of a drilling rig. The electrodynamic brake (sometimes called a magnetic brake) serves as an auxiliary to the mechanical brake when pipe is lowered into a well. The braking effect in an electrodynamic brake is achieved by means of the interaction of electric currents with magnets, with other currents, or with themselves.