Investigation of nonmetallic inclusions in high-speed steels

The morphology, structure, and amount of nonmetallic inclusions in M2 high-speed steel and an experimental version modified with an addition of Al have been studied. The addition of aluminum to high-speed steel leads to an increase in nonmetallic inclusions, especially Al2O3 and AlN. The morphologies of nonmetallic inclusions in M2Al are irregular with sharp outlines; this can result in crack initiation interfaces between the inclusions and the matrix during high-temperature quenching.