A study on chloride induced depassivation of Fe-P-C-Si and Fe-P-C-Si-N steels in simulated concrete pore solution

International Conference on Recent Advances in Materials, Mechanical and Civil Engineering

材料科学;机械制造;土木建筑工程

Mehta, Yashwant^1 ; Chaudhari, Gajanan P^1 ; Dabhade, Vikram V^1

Department of Metallurgical and Materials Engineering, IIT Roorkee, 247667, India^1

关键词: Concrete pore solutions;    Corrosion behaviour;    Electrochemical impedance spectroscopy measurements;    Elemental distribution;    Linear polarization resistance;    Plain carbon steels;    Simulated concrete pore solution;    Steel specimens;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/330/1/012014/pdf
DOI  :  10.1088/1757-899X/330/1/012014

来源: IOP

【 摘 要 】

The corrosion behaviour of high phosphorous steels containing varying amounts of silicon and nitrogen was studied by potentiodynamic polarization, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. The morphology of a steel specimen tested in chloride containing concrete pore solution was studied using scanning electron microscope (SEM) and the elemental distribution at the pitting corrosion area was investigated using electron dispersive spectroscopy (EDS). The results showed that the capacitance increased and resistance declined with immersion time in Ca(OH)2solution containing 0.1% chloride for plain carbon steel. The opposite was observed in the case of the high phosphorous steels. The potentiodynamic polarization and LPR results complement the EIS findings. Corrosion behaviour could be described with an equivalent circuit having two time constants. The creation, expansion and degradation of the passive layer were discussed with the help of the equivalent circuit elements. The SEM-EDS studies revealed that MnS inclusions at the surface could have a role in the initiation and growth of pits and that phosphorous was present at the pit free surface of the steel.