Investigation on Mechanical Properties and Immersion Corrosion Performance of 0.35%C–10.5%Mn Steel Processed by Austenite Reverted Transformation (ART) Annealing Process

Abstract

The objective of this work is to evaluate the mechanical properties and immersion corrosion performance of 0.35%C–10.5%Mn steel processed by austenite reverted transformation (ART) annealing process. Microstructure analysis revealed the formation of the well-refined microstructure having martensite (α′) and retained austenite (γ) phases after 4 h of ART-annealing compared to non-heat-treated steel. This phase transformation caused a 50% improvement in total elongation and 42.85% in impact toughness. ART-annealing for 16 h offered an optimum combination of mechanical properties. Immersion corrosion test of 168 h was also performed to evaluate the corrosion performance in a 5% NaCl solution. ART-annealed samples exhibited crack-free, thick and uniform oxide layer with Cl precipitates. ART-annealing for 4 and 16 h produced a porous-structured corrosion product, while 8 and 12 h of ART-annealing produced rod-shaped corrosion product. The performance of the porous-structured corrosion product in inhibiting corrosion mechanism was much better than the rod-shaped corrosion product. The ART-annealing process performed for 16 h exhibited maximum corrosion resistance as evidenced by the lowest value of weight loss (0.64 mg/cm2).