Corrosion Resistance of Structural Materials in Tungstate Solutions.

It is shown that the corrosion activity of tungstate solutions is caused by the presence of fluoride ions and by the total alkalinity. We determine the optimal mode of welding of carbon, chromium, and nickel-chromium steels. In the original tungstate solution, the maximum corrosion rate is recorded for specimens of VSt3sp carbon steel with welded joints. The electrochemical studies show that, in the original solution at room temperature, this type of steel corrodes in the passive state. As temperature or the concentrations of components of the solution increase to the values corresponding to the evaporated solution, the analyzed steel begins to corrode in the active state. Chromium and nickel-chromium steels (08Kh13, 08Kh22N6T, and 12Kh18N10T) preserve their passive state both in the original solution and in the evaporated solutions. The PON-A, PON-B, and PON-V paronites and TMKShch rubber are chemically stable and, therefore, suitable for the production of gaskets intended for operation in the original Na2WO4 solutions. [ABSTRACT FROM AUTHOR]