Dear Mandana Ghasemiansafaei

I think these papers could be helpful for you

Dear Mandana Ghasemiansafaei

As you said in your interesting question that the corroded phase is a pure ferrite and this phase possess excessive galvanic corrosion, in this case one should think that there are areas of different crystallographic orientations leads to the electrochemical potential difference and so micro galvanic cells. In [1] , very interesting investigation for the most important factor that the inhomogeneous distribution of strained and unstrained regions left behind by the metallurgical processes,( such as fabrication, annealing, and shaping) gives rise to an inhomogeneous distribution of a large number of micro-sized galvanic cells which, in a corrosive environment, cause the initiation and growth of localized corrosion. So, it is a case study of the role of metallurgy in the localized corrosion of carbon steel as in [1].

Best regards

[1]https://www.scirp.org/journal/paperinformation.aspx?paperid=88704

Dear Mandana

I agree with Professor Hussein.

The observations of localized galvanic corrosion of a pure ferrite phase could occurred due to the present of differential regions of dislocation density, i.e.,

inhomogeneous distribution of strained and unstrained regions, in the phase.