Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

Abstract

Dual-phase (DP) steels are produced from a specific heat treatment procedure and have recently emerged as a potential class of engineering materials for a number of structural and automobile applications. Such steels have high strength-to-weight ratio and reasonable formability. The present study aims to investigate the effects of four different and conventional heat treatments (i.e., hot rolling, normalizing, annealing, and intercritical annealing) on the resulting microstructural patterns and on the electrochemical corrosion behavior. Electrochemical impedance spectroscopy (EIS) and Tafel plots were carried out on heat treated steel samples in a 0.5 M NaCl solution at 25 8C with neutral pH. An equivalent circuit analysis was also used to provide quantitative support for the discussions. The normalizing and the annealing heat treatments have provided the highest and the lowest corrosion resistances, respectively. The intercritical annealing and as-received (hot rolled) low carbon steel samples have shown similar corrosion behavior. Although a deleterious effect on the corrosion resistance has been verified for DP steel due to the residual stress from the martensite formation, it combines good mechanical properties with intermediate electrochemical corrosion resistance.

Electrochemical corrosion behaviour of a Ti‐IF steel and a SAE 1020 steel in a 0.5 M NaCl solution

“…In this context, it seems that the steel carbon content and pearlite grain's formation are the sole parameters that contribute to the slight decrease in the resulting electrochemical behaviour of the LC steel samples. This seems to be associated with the galvanic couple formation, which occurs both between pearlite and the ferrite matrix and inside the pearlitic mixture where cementite (carbon rich) can induce the corrosion action of the neighbouring ferrite (more active areas), as previously reported 16. It seems that corrosion in the IF steel sample will occur initially along the ferrite grain boundaries and will develop further uniformly towards the ferrite grain centre.…”

“…Ferrite grains are considered less noble regions (where initiation of corrosion becomes easier and corrosion can develop more quickly) when compared to pearlite areas 16, 28, 29. Pearlite seems to be less affected (nobler phase) since it has a rich carbon content region (cementite lamellae), as shown in Fig.…”

“…It is well known that the mechanical properties of several materials and alloys are strongly affected by the resulting microstructure 11–15. A continuous yielding, low yield strength, high ultimate tensile strength and high and uniform elongation are intrinsic and attractive mechanical properties of low and ULC steels 3, 4, 16–19.…”

“…Recent studies have shown the effect of the microstructural arrangement on the corrosion resistance for several commercial alloys 14–16, 20–26, but investigations concerning the electrochemical corrosion behaviour of LC, ULC and IF steels are relatively scarce and limited.…”

Corrosion properties of low carbon steel prepared by submerged friction stir processing

“…Low carbon steels are indispensable structural materials in various industrial fields for their high mechanical properties and low price. However, the industrial application of low carbon steel had been restricted due to the poor corrosion resistance . Severe plastic deformation (SPD) technique has been widely used to fabricate the fine‐grained bulk materials, such as equal‐channel angular pressing (ECAP), accumulative roll bonding, and high pressure torsion .…”