Nucleation and growth of a passive film on AISI 420 martensitic stainless steel under potentiostatic conditions
Zgodnja faza nastanka pasivne plasti na AISI 420 nerjavnem jeklu pod potenciostatičnimi pogoji

english

2002

volume 49, issue 1

Slovensko kemijsko društvo
(Obvezni izvod spletne publikacije)

The kinetics of the early stage s of passive film formation on AISI stainless stell in mixtures of 0.1M ?$H_2$?S?$O_4$? and 0.1M N?$a_2$?S?$O_4$?, with pH-values of 2.42, 2.85 and 3.33, were studied at different anodic potentials. The potentiostatic step method was used as an electrochemical technique in which the anodic current density was measured as a function of time. For analysis of the measured data, the theory of "topochemical reaction" was applied for the charcterization of the exponent n in that part where the stepest current decay was observed. Through this theory, which includes the Erofeev equation, the number of conversion steps could be obtained, as well as the numebr of directions in which the nuclei grow. It was found that this theory can be sucessfully applied to the passivation process of AISI 420 stainles steel.

16.09.2009