Corrosion behaviour of a quenched and partitioned medium carbon steel in 3.5 wt.% NaCl solution

Abstract In this work, the corrosion characteristics of a quenched and partitioned (Q&P) medium carbon steel in a 3.5 wt.% NaCl solution were investigated by various surface analysis techniques and then compared with those of the quenched and tempered steel with the same composition. Both steels exhibited nearly identical corrosion variation trends. However, the Q&P specimen demonstrated a lower corrosion rate. The formation of retained austenite in the carbon-enriched state increases the corrosion potential of the carbon-depleted martensitic matrix and decreases the residual tensile stress on the Q&P surface, thus enhancing its corrosion resistance.