Modern cooling water treatment. The mechanism of membrane inhibition of steel corrosion

By developing highly efficient hardness stabilizers, it has proved possible to formulate a new concept of cooling water treatment, provided that the capabilities of the stabilizers are properly used. The new concept is kind to the environment, because it avoids the use of heavy metals. The adopted principle of membrane inhibition is optimum corrosion inhibition which, pH-control excepted, has to be maintained at a pH value of between 8. 5 and 9. The structure of these very thin membranes of PBTC (phosphoric butane tricarbolic acid) and their composition are described. A series of key factors has been systematically investigated, employing modern methods of surface analysis.