To provide a carburizing, nitriding or carbonitriding method which spends a short period of time for heat treatment.
This carburizing, nitriding or carbonitriding method includes the steps of: projecting a projection material composed of at least any of a carbide powder, a nitride powder and a carbonitride powder onto the surface of steel having been cut, in the state of having been heated to a high temperature of 500C or higher with a shot-peening machine to embed the projection material into the surface of the steel; and subsequently quenching the steel. Thereby, carburizing, nitriding or carbonitriding characteristics equal to those obtained by carburizing, nitriding or carbonitriding treatment using a gas can be obtained in a shorter heating period of time than that of the treatment, and a rolling device having the long life can be manufactured at a low cost with high efficiency while saving energy.
Yoshiaki Naito
Cui Shu Tetsu