Date of Award
Doctor of Philosophy
The properties of passive films formed on 440C stainless steel were investigated using advanced electrochemical techniques for the purpose of establishing a method to measure film stability directly in passivation baths. Electrochemical measurements were sensitive to the passive film properties and were able to quantify the effect of cooling rate on passive film stability. The various techniques used--linear polarization, AC impedance, small amplitude cyclic voltammetry (SACV), and coulostatic transient measurements--provided results that exhibited excellent agreement with the AC impedance technique providing the most information about the interfacial reactions. Full electrochemical characterization of the passive film stability required an evaluation of both the polarization resistance and the interfacial capacitance, thus precluding the use of DC measurements. The coulostatic technique demonstrated the most promise as a monitoring tool as it provided a rapid, simple measurement of both the polarization resistance and capacitance.
Walzak, Timothy Lawrence, "Electrochemical Properties Of Passive Films On 440c Stainless Steel" (1991). Digitized Theses. 1942.