It is found that the alloying elements segregation in grains and the grain boundary cleanliness control the yield stress value and the tough-strength properties of this material respectively.

The ways to heighten the ribbed rebar quality were to improve the liquid steel cleanliness, continuous casting process, the heating temperature and rolling heat control during steel rolling process.

This is driving to a better control of the temperatures in the gearbox and to the optimization as well as monitoring of the cleanliness of the oil in the system.