Technology of Borating Hardening of the Chaff-Cutter Drum Knives in a Grain Harvester Combine

The methods of hardening of the chaff-cutter drum knives in a grain harvester combine are analyzed. The wear resistances of 65g steel samples hardened by quenching and borating and heating by high-frequency currents are compared. The results of field tests of the hardened knives are presented. These results are used to propose a design for a hardening coating. A two-coil induction heater is suggested for simultaneous heating of both face edges of a knife.