High Mn cast iron improves the recycling rate of high tensile steel sheets and increases their strength, thereby expanding the range of use of cast iron materials. It is thought that erosion wear resistance can be improved by adding Cr to high-Mn cast iron. In this study, Cr was added to high Mn flake graphite cast iron, the microstructure and wear resistance were investigated, and the wear mechanism was elucidated. The erosion rate decreased with increasing Cr content. When the Cr content increased to 0.4%, the pearlite was refined and the matrix hardness increased. When the Cr content exceeded 0.6%, Cr carbide formed, and wear decreased as the matrix hardness increased. By changing the matrix microstructure from ferrite and pearlite to all pearlite, and further from pearlite and carbide, surface plastic deformation was suppressed and erosion wear was reduced. The changes in microstructure and hardness of the matrix were caused by the reduction of erosion wear.
