Abstract
The aim of the present work was to study the passive film stability and pitting corrosion behavior of the AISI 409 stainless steel. The electrochemical tests were carried out in 0.1 M NaCl solution at room temperature. The general electrochemical behavior was assessed using electrochemical impedance spectroscopy (EIS) measurements whereas the semiconducting properties of the passive film were evaluated by the Mott-Schottky approach. Pitting corrosion was investigated using potentiodynamic and potentiostatic polarization tests. Surface morphology was examined using confocal laser scanning microscopy and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the composition of precipitates that could act as preferential sites for the onset of pitting corrosion. The results showed that the passive film presents n-type semiconductive behavior. Grain boundaries played an important role as pitting initiation sites for the AISI 409 stainless steel.
Highlights
AISI 409 is a ferritic stainless steel commonly used in automotive exhaust systems as well as farm equipment, structural supports and transformers[1]
Titanium-rich precipitates have been identified in Ti-stabilized ferritic stainless steels
The microstructure of the AISI 409 stainless steel was further characterized by scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) analysis in order to identify the precipitates observed in Figs. 1(a) and 1(c)
Summary
AISI 409 is a ferritic stainless steel commonly used in automotive exhaust systems as well as farm equipment, structural supports and transformers[1]. The engineering applications of the AISI 409 stainless steel have been established due to its relatively low cost and good corrosion resistance at high temperatures. This material is a titanium-stabilized grade with low carbon content[4]. The presence of titanium and the low carbon content are typical features for decreasing the susceptibility to intergranular corrosion during welding operations or high temperature applications such as for components of automotive exhaust systems. Titanium-rich precipitation can lead to the formation of galvanic couples in the microstructure of ASI 409 stainless steels due to the different activity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
