The Use of Cyclic Polarization Method for Corrosion Resistance Evaluation of Austenitic Stainless Steel 304L and 316L in Aqueous Sodium Chloride Solut

Abstract

Corrosion behavior of austenitic stainless steels 304L and 316L types in various concentrations of aqueous sodium chloride solutions were investigated related to its pitting corrosion resistance. Experimental testing was carried out by using cyclic polarization method at room temperature (27 o C) to evaluate the corrosion mechanism by considering breakdown potential (E b) and protection potential (E p). Aqueous sodium chloride solutions were prepared with various concentration i.e. 1%, 2%, 3.5%, 4% and 5% w/v. The testing results were represented by cyclic potentiodynamic polarization curves for both alloys which showed potentials that indicated the onset of potentials E b and E p respectively. The results were influenced by sodium chloride concentrations and the chemical composition of alloys. Rank of the values of E b and E p of 304L and 316L at various sodium chloride concentrations from the highest to the lowest were 1%, 2%, 5%, 4%, 3,5% w/v NaCl consecutively. It was observed that the lowest corrosion resistance of both alloys was at 3,5% w/v NaCl which was similar to typical seawater solution with maximum dissolved oxygen solubility. It was shown that 316L has more positive potentials for both E b and E p as well as its difference values compared to SS 304L at all concentrations of aqueous sodium chloride solution.

Improvement of the corrosion behavior of AISI 304L stainless steel by deep rolling treatment under cryogenic cooling

“…Particularly, austenitic stainless steels have been widely applied in chemical industries owing to the formation of surface protective passive film [1]. Their chromium content varies from 16 to 28% and nickel content varies from 3.5 to 32% [2]. Actually, chromium protects the metal substrate from uniform and localized corrosion e.g., pitting, crevice, stress corrosion cracking and intergranular corrosion by the creation of insoluble film of protection [3].…”

Corrosion behavior and degradation mechanism of micro‐extruded 3D printed ordered pore topological Fe scaffolds

“…The susceptibility of localized corrosion during measurement was evaluated by calculating its breakdown potential () and protection potential (). In brief, is a potential that specifies the onset of local corrosion, and designates the halted of local corrosion 38 . CPP curve is an amalgamation of anodic and cathodic polarization that forms a closed loop (hysteresis loop) process.…”

Investigation of Corrosion Protection of Austenitic Stainless Steel in 5.5 M Polluted Phosphoric Acid Using 5-Azidomethyl-7-morpholinomethyl-8-hydroxyquinoline as an Ecofriendly Inhibitor

“…AISI 321 oxidation in 5.5 M polluted phosphoric acid is suggested as a general corrosion characterized by a loss of thickness easily detectable by a simple observation of the surface by the naked eye (Figure 5). Furthermore, an anodic cyclic potentiodynamic polarization of AISI 321 in 5.5 M polluted phosphoric acid at 20°C after one hour of immersion time was registered (Figure 5) and shows a superposition of the forward and backward lines of the curve, indicating the absence of any stable pitting on the surface [14]. In that case, the results of the hydrogen released allow quantifying the damage (thickness loss per unit of time), by using the following relation:…”