The transition of alloyed white cast irons for steel rolling and mineral pulverizing mill rolls changed from low-alloyed white cast iron via Ni-hard to high Cr cast iron. High Cr cast iron has been used for a long time because of its high abrasive wear resistance. However, a large volume fraction of eutectic chromium carbide precipitated in high Cr cast iron reduced the toughness and caused failure under an impact load. Until now, therefore, a new alloy which had greater toughness and higher performance has been researched and developed. To achieve this purpose, cast iron containing multiple types of carbides with higher hardness than chromium carbides and low volume fraction of carbides had to be designed.