The conventional understanding of the cathodic protection mechanism is illustrated in the definition of cathodic protection arising from the research of Mears and Brown in 1938. That is, cathodic protection is complete when the corrosion cell cathodes are polarized electronegatively to the open circuit potential […]
Some recent papers contain inaccurate information regarding the validity of the -850 mVcsE current applied criterion, the so-called on-potential criterion. To qualify as a corrosion control criterion the -850 mVcsE value must imply a sound engineering judgment of the corrosion rate. Only the -850 mVcsE […]
The 100mV cathodic polarization criterion is being used more extensively on piping in the oil and gas industry which has prompted a discussion on the limits of its use. This paper summarizes the technical literature on the validity of this criterion with respect to elevated […]
Prestressed concrete cylinder pipe (PCCP) used for water and sewer transmission service is composed of a thin wall steel cylinder, lined on the interior and exterior with cement mortar, and reinforced by prestressing wire either wrapped around the steel cylinder or embedded in the exterior […]
External corrosion of iron watermains has been a problem for municipalities for over 100 years. The three main causes of corrosion, in a historical context are: stray currents from electrified transit systems dissimilar soils galvanic corrosion All of these causes remain with us today, although […]
The service life of Mg anode cathodic protection systems installed on iron water mains has, in some instances, been significantly less than design calculations would predict. Testing of high-potential Mg alloys from various suppliers using the ASTM G97-89 test method indicates that efficiencies are widely […]
Although cathodically protected pipelines are often connected directly to electrical ground in stations and plants, there is little information on the amount of current required to polarize various grounding materials such as copper, tinned copper, stainless steel, silicon iron, and galvanized steel. This paper presents […]
