Pertechnetate as an inhibitor of corrosion

Already in 1952 the effectiveness of TcOj ions in aqueous solutions for the corrosion inhibition of iron and carbon steels was discovered [32.33]. A specimen of steel was efficiently protected against corrosion at temperatures of up to at least 250 C in aerated distilled water containing 5-10 M TcOj, one-tenth of the concentration required for corrosion inhibition by CrO. The test specimen remained bright and unchanged in weight after being exposed for 20 years in the aqueous TCO4 solution at pH 6. To achieve inhibition under very corrosive conditions not more than 2.2 lO technetium atoms per cm- must be deposited on the surface of the specimen, about a tenth of a monolayer, ffowever. an inhibited specimen corroded at once when 

Of course, the actual application of pertechnetate ions to corrosion inhibition of iron and carbon steels will obviously be a great problem because of the radioactivity of Tc, even in dilute solutions of TcO. A pertechnetate concentration of 5 10 M corresponds to a specific radioactivity of 84.15 pCi/l or 3.11 U/ Bq/1. Nevertheless, the corrosion inhibiting property of TcOj was proposed to be used in steam-generating nuclear reactors [42,43[- 

Palmer. Brigham Young University, Diss. Abstr. Intern. B35, 2644 (1974) 

Spitsvn. G.N. Pirogova. R.I. Korosteleva, and G.F. Kalinina. Dokl. Akad. Kauk. SSSR, 298. 149-151 ( l988) 

---