Frequency–Time Domain Analysis Based on Electrochemical Noise of Dual-Phase (DP) and Ferrite–Bainite (FB) Steels in Chloride Solutions for Automotive Applications

• Published in: Metals (Basel ) Vol. 14; no. 11; p. 1208
• Main Authors: Almeraya-Calderón, Facundo, Montoya-Rangel, Marvin, Nieves-Mendoza, Demetrio, Jáquez-Muñoz, Jesús Manuel, Baltazar-Zamora, Miguel Angel, Landa-Ruiz, Laura, Lara-Banda, Maria, Maldonado-Bandala, Erick, Estupiñan-Lopez, Francisco, Gaona-Tiburcio, Citlalli
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 23-10-2024
• Subjects: Automobile industry; Automotive bodies; Bainite; Calcium chloride; Chemical elements; Chloride resistance; Corrosion mechanisms; Corrosion resistance; Corrosion resistant steels; Corrosion tests; Decomposition; Deicing salt; Electrochemical noise; Electrodes; Exposure; Frequency analysis; Grain size; High strength low alloy steels; Iron constituents; Localized corrosion; Magnesium chloride; Mechanical properties; Microstructure; Optical microscopy; Room temperature; Scanning electron microscopy; Sodium chloride; Steel; Temperature; Time domain analysis; Uniform attack (corrosion); Wavelet analysis; Wavelet transforms; United States > US
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met14111208

The automotive industry uses high-strength (HS), low-alloy (HSLA) steels and advanced high-strength steels (AHSSs) to manufacture front and rear rails and safety posts, as well as the car body, suspension, and chassis components of cars. These steels can be exposed to corrosive environments, such as in countries where de-icing salts are used. This research aims to characterize the corrosion behavior of AHSSs based on electrochemical noise (EN) [dual-phase (DP) and ferrite–bainite (FB)]. At room temperature, the steels were immersed in NaCl, CaCl2, and MgCl2 solutions and were studied by frequency–time domain analysis using wavelet decomposition, Hilbert–Huang analysis, and recurrence plots (RPs) related to the corrosion process and noise impedance (Zn). Optical microscopy (OM) was used to observe the microstructure of the tested samples. The results generally indicated that the main corrosion process is related to uniform corrosion. The corrosion behavior of AHSSs exposed to a NaCl solution could be related to the morphology of the phase constituents that are exposed to solutions with chlorides. The Zn results showed that DP780 presented a higher corrosion resistance with 918 Ω·cm2; meanwhile, FB780 presented 409 Ω·cm2 when exposed to NaCl. Also, the corrosion mechanism of materials begins with a localized corrosion process spreading to all the surfaces, generating a uniform corrosion process after some exposition time.