Corrosion characteristics of a quenching and partitioning steel determined by electrochemical impedance spectroscopy

Abstract

Among the advanced high-strength steels, quenching and partitioning (Q&P) steels provide excellent ultimate tensile strength in combination with good ductility. The mass fraction of martensite and austenite can be tailored by the Q&P treatment. In this study, the impact of the microstructure on the corrosion behaviour is investigated. For this, the microstructures of two Q&P processing routes and a quenched and tempered state are analysed using scanning electron microscopy and X-ray diffraction. Electrochemical impedance spectroscopy is conducted using two different media in order to determine the time evolution of corrosion rates during short-time corrosion. The results of this study demonstrate that correlations between Q&P microstructures and the corrosion behaviour can be analysed in detail with these experimental methods.