METHOD OF HARDENING OF CAST CUTTING TOOL FROM HIGH-SPED STEEL Russian patent published in 2001 - IPC

FIELD: methods of hardening of cast cutting tools for high- speed steel. SUBSTANCE: method includes saturation of tool from daub containing, wt. %: ferrotitanium 50- 60; boron carbide 20-30; potassium ferricyanide 15-25; ammonium chloride 2-3; and subsequent triple tempering in combination with sulfidizing in sealed muffle in medium of sodium sulfate at temperature of 550- 570 C for 1 h. Prior to saturation from daub, tool is ground, sharpened and subjected to cementation at temperature of 980-1020 C with holding at this temperature for 1.5 h and cooling together with muffle. Daub composition is thinned in ethyl silicate to obtain past-like material. Ferrotitanium is used in form of FeTi-75. After application of paste to tool surface and drying, tool is heated in inductor with high-frequency currents to temperature of 1180- 1250 C with holding at this temperature for 3-5 min and cooling with interim cooling in oil at temperature of 60-80 C. EFFECT: higher heat and wear resistance of surface layers of cutting tool. 5 cl, 1 tbl