Abstract: A method of electrolytic strengthening on the cutting edge of the cutter is studied to prolong the life of the cutter and to improve the cutting stability. The equipment and the manufacturing processes are developed for electrolytic strengthening on the cutting edge of the rotary cutter. High-speed steel tap is taken as an example, some process parameters of electrolytic strengthening on the cutting edge of the cutter, such as electrolyte, cathode materials, cutting speed and the electrolyte temperature as well as the relationship between the cutting edge strengthening capacity and the distance between anode and cathode, current density, polishing time and the voltage between anode and cathode, are studied. If electrolytic strengthening with optimized processes is used to polish taps, the orderly cutter edge of taps will have uniform strengthening degree of each tooth knife edge, the geometry of the cutter edge can meet the requirement of the cutter edge strength, and the surface roughness of the rake face of the taps can be reduced. When the above research results are applied to cutting 40Cr, ZG230～450 and 1Cr18Ni9Ti, the 40Cr, ZG230～450 taps life can be prolonged by 200%, but there is no obvious change in life of the stainless steel taps. The study indicates that the service life of high-speed steel taps can be prolonged by electrolytic strengthening, and the effect is related with the machined materials and the strengthening degree of the cutting edge.

Key words: Electrolytic strengthening, High-speed steel, Taps