Corrosion response of ultra-high strength steels used for automotive applications

Abstract

The corrosion resistance properties of two ultra-high strength steels, Docol 1200 and 1400 were studied in 3.5 wt% NaCl solution using chemical and electrochemical techniques supported by surface characterization techniques namely scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), atomic force microscope (AFM), and optical profilometer. The mechanical properties of both Docol 1200 and Docol 1400 uncorroded and corroded were determined by tensile test. Results obtained reveal that the two alloys exhibit similar mechanical properties. Corrosion has effect on the mechanical properties of the alloys. Corrosion studies reveal that both Docol 1200 and 1400 are prone to corrosion in NaCl environment. A corrosion rate of 30.6 mpy and 49.6 mpy was recorded for a Docol 1200 at 25 °C and 60 °C, respectively. For Docol 1400, the corrosion rate obtained at 25 °C and 60 °C was 32.7 mpy and 52.4 mpy, respectively. Docol 1200 is adjudged to exhibit superior corrosion resistance property than Docol 1400. The optical profilometric results disclose that Docol 1200 and Docol 1400 suffered pitting corrosion in NaCl solution. Pitting corrosion was more severe with Docol 1400 than 1200.

Chemical, Electrochemical, and Surface Morphological Studies of the Corrosion Behavior of the AZ31 Alloy in Simulated Body Fluid: Effect of NaOH and H2O2Surface Pretreatments on the Corrosion Resistance Property

“…It is interesting to note the smaller CPE f and CPE dl values obtained for the treated surfaces relative to the untreated surface. This parameter provides information on the characteristics of the surface film . The smaller CPE f and CPE dl values for the treated surfaces compared to the untreated surface are indicative of a more compact and thicker film on the treated surfaces …”

“…This parameter provides information on the characteristics of the surface film . The smaller CPE f and CPE dl values for the treated surfaces compared to the untreated surface are indicative of a more compact and thicker film on the treated surfaces …”

“…This parameter provides information on the characteristics of the surface film. 23 The smaller CPE f and CPE dl values for the treated surfaces compared to the untreated surface are indicative of a more compact and thicker film on the treated surfaces. 23 The polarization curves obtained for the untreated and treated AZ31 Mg alloy samples after 30 h of immersion in SBF at 25 °C are shown in Figure 1c.…”

“…23 The smaller CPE f and CPE dl values for the treated surfaces compared to the untreated surface are indicative of a more compact and thicker film on the treated surfaces. 23 The polarization curves obtained for the untreated and treated AZ31 Mg alloy samples after 30 h of immersion in SBF at 25 °C are shown in Figure 1c. The polarization parameters derived from the analysis of the curves are also listed in Table 1b.…”

Efficient Synthesis of 6,7-Dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile Compounds and Their Applicability As Inhibitor Films for Steel Alloy Corrosion: Collective Computational and Practical Approaches

“…To validate the assertion of an enhanced adsorbed layer with increasing inhibitor dose, we inspected the values of the Y f and Y 0 . Commonly, the restrictions Y f and Y 0 describe the features of a surface film of the CS alloy 51 and the smaller the value, the superior the surface layer. 52 As can be observed in Table 2 , the value of Y 0 for the uninhibited medium is 75.6 μΩ –1 s n cm –2 , whereas that of the 4.0 × 10 –5 mol L –1 inhibited medium is 12.56, 16.65, 26.99, and 31.61 μΩ –1 s n cm –2 in the presence of CAPD-1 , CAPD-2 , CAPD-3 , and CAPD-4 , respectively.…”