Using thionates for noise Experiments - a reasonable combination?

摘要

The detection of intergranular corrosion (IGC) initiation of aus-tenitic stainless steel (AISI 347) coupon specimens was investigated using electrochemical noise (EN) measurements. The tests were performed in acidic sodium tetrathionate (Na{sub}2S{sub}4O{sub}6) solution. The IGC initiation in tetrathionate solution could not be clearly detected by the electrochemical potential noise signal due to interferences of the noise signal with chemical processes which occurred in the test solution. This was confirmed by tests with inert platinum specimens. It was concluded that EN results obtained by tests in thionate or comparable sulfur containing solutions should be regarded with great care and verified, e.g., by tests with inert specimens.