This invention discloses a heat treatment method for homogenizing the
microstructure of the rim of a high-
performance tool steel paper cutter, relating to the field of paper cutter heat treatment technology. The method includes the following steps: After preheating the rim to a subcritical state, a polarization pulse is applied through a follower
contact electrode to form a surface deconstruction zone and superequilibrium vacancies on the rim surface; the follower
contact electrode is then fixedly connected to a follower jet
assembly to limit the transfer
lag time of the surface deconstruction zone into the cryogenic medium; subsequently, an alternating
magnetic field is synchronously applied in the cryogenic medium jet zone to break the surface vapor isolation film and freeze the superequilibrium vacancies; finally,
acoustic emission signals are collected during the
tempering cycle, and an alternating
magnetic field is applied based on the characteristic
acoustic signature closed loop to control the segregation and
precipitation of carbon atoms towards the frozen vacancies. This method maintains the rigidity of the blade back and the stability of the bimetallic interface, achieving
microstructure refinement and
precipitation homogenization of the rim, and is applicable to the rim heat treatment of bimetallic composite paper cutters.