Improvement of the anti-corrosion property of twinning-induced plasticity steel by twin-induced grain boundary engineering

The effects of thermal-mechanical processing (TMP) on the microstructure and anti-corrosion property of twinning-induced plasticity (TWIP) steel are investigated. It is found that, the corrosion resistance of TWIP steel has been significantly improved with the corrosion potential increased from −0.92 V to −0.69 V and the corrosion current density reduced from 8.76 × 10−5 A/cm2 to 1.92 × 10−5 A/cm2. Electron back-scatter diffraction (EBSD) technique is employed to analyze the grain boundaries distributions of TWIP samples. The results indicate that the interrupted high angle boundaries network is the key to the improvement of the corrosion resistance of TWIP steel while the fraction of low-Σ coincidence site lattice boundaries is just slightly increased from 81% to 86%.