Abstract: The present invention provides compositions and methods which are effective to prevent corrosion of metal surfaces involved in refining solutions having relatively high partial pressures of carbon dioxide. The compositions of the present invention comprise mixtures of a pyridinium quaternary salt and an organic compound, such as thiourea, which contains at least one sulfur atom double bonded to a carbon atom. The compositions are added substantially continuously to the solution to be treated to result in a final concentration of at least about 30 ppm of pyridinium quaternary salt, preferably between about 56-70 ppm, and at least about 5 ppm double bonded sulfur containing compound, preferably between about 10-13 ppm.

Abstract: A system, method and probe for monitoring the corrosion rate of different metals in identical corrosive fluids and under identical conditions, such metals being employed as electrodes other than reference electrodes in a probe having also a reference electrode. The preferred probe comprises a probe body holding at least four electrodes, where one is placed in the center and the others around it in a circle. The center electrode is preferably used as a permanent reference electrode. Each electrode on the circle can then be connected in turn to a channel on a multistation PAIR meter as test and auxiliary electrodes, whereby the corrosion rate on each of them can be monitored in turn. This arrangement greatly enhances the utility of the multistation PAIR meter and with only two entry ports in a system, all channels can serve to answer specific questions on specific electrodes or metals. The novel probe can also be used with a one channel PAIR meter employed with a multi-station manual switch.

Abstract: The corrosion of galvanically coupled metals can be measured and monitored by linear polarization techniques using a test galvanic electrode comprising two individual electrodes of different metals preferably connected end to end with a rigid metallic fastener. The galvanic electrode is treated as a single electrode and can be used as the test electrode in any two or three electrode configuration which includes at least the test electrode and a reference electrode. A three electrode configuration, including also an auxiliary electrode, is adapted for use in combination with the PAIR meter.