METHOD OF HARDENING OF CIRCULAR SAWS Russian patent published in 1998 - IPC

FIELD: thermal treatment of articles in electrolyte, hardening of teeth of circular saws for cold cutting of tubes and roll-formed sections of rolled products. SUBSTANCE: method of hardening of circular saws made from chromium steel includes dipping of teeth into flow electrolyte, passing of pulses of electric current through it and later cooling of teeth. For increase of wear resistance of circular saws density of current in pulses is set at 7- 0-10.0 A/sq.cm with pulse duration of 1-3 s and duty factor of 1.2-1.8. In intervals between pulses density of current is kept at 4.2-5.9 A/sq. cm and duration of passage of pulses amounts to 4-10 s. EFFECT: increased wear resistance of circular saws. 1 cl, 1 tbl