Cathodic cor­rosion pro­tection
for your objects and struc­tures

Cor­rosion occurs whe­rever metal sur­faces come into contact with elec­tro­lytes in which oxygen is present. In most cases, this elec­trolyte is water mixed with addi­tives such as salt or other che­mical sub­s­tances. The strength and type of cor­rosion depends on the com­po­sition. Cor­rosion pro­tection is the­r­efore necessary to maintain the long-term sta­bility of buil­dings that are made of or contain metals.

CP or cathodic cor­rosion pro­tection is used either as a legally pre­scribed sup­plement to passive cor­rosion pro­tection such as a coating to provide long-term pro­tection. For other objects where coating is not tech­ni­cally pos­sible or not prac­tical, cathodic cor­rosion pro­tection is used inde­pendently. This is typi­cally the case with sheet piling in harbor areas, where the abrasion of a coating is so severe due to the sandy envi­ronment that it would not last anyway.

Cor­rosion is an oxi­dation process that always requires a com­bi­nation of oxygen and moisture. The ori­ginal prin­ciple is the affinity of steel in com­bi­nation with oxygen to go into a lower energy state and that is cor­rosion. At the atomic level, the metal reacts to the pre­sence of oxygen and a liquid by releasing elec­trons, causing it to decompose.

Cathodic cor­rosion pro­tection works by turning the metal of the pro­tected object into a cathode in the elec­trical circuit by means of an elec­trical source. In this way, elec­trons are sup­plied to the object to be pro­tected, which are then available at the phase boundary (where the metal comes into contact with oxygen and a liquid) and the­r­efore no elec­trons can be removed from the atomic structure of the metal. This pre­vents oxi­dation and cor­rosion.

Various envi­ron­mental pro­tection and safety regu­la­tions require the use of Cathodic Pro­tection. Depending on the envi­ronment in which the pro­tected object is used, the regu­la­tions of the stan­dards and regu­la­tions of the respective respon­sible bodies come into force. Cathodic cor­rosion pro­tection is man­datory for all liquids or gases that are hazardous to drinking water, toxic, harmful to the envi­ronment or could explode.

The DVGW (German Tech­nical and Sci­en­tific Asso­ciation for Gas and Water) defines a set of regu­la­tions that sti­pu­lates the requi­re­ments and obli­ga­tions for the pro­tection of buil­dings. Potential danger to the envi­ronment must be averted. For example, CP is important to ensure the tightness of metal pipe­lines in order to prevent safety-relevant ope­rating mate­rials from leaking into the ground­water.

Passive cor­rosion pro­tection can also provide a remedy, but only if the coating is com­pletely unda­maged and the surface is thus sepa­rated from oxygen and moisture. Passive pro­tection alone is the­r­efore never safe and is usually secured by cathodic cor­rosion pro­tection. In some cases, cathodic cor­rosion pro­tection is even used exclu­sively.