Near-net forming method of impact runner

The embodiment of the invention discloses a near-net forming method for an impact rotating wheel, and castings such as a water bucket unit and the like are formed in a variable curved surface channel of an electroslag casting crystallizer in an overflow manner through multi-electrode synchronous melting. The consumable electrodes are inserted into electrode channels of the electroslag casting crystallizer, the positions of the electrode channels where the consumable electrodes are inserted are selected according to the section position of the electroslag casting crystallizer, and the number of the electrode channels where the consumable electrodes are inserted is selected according to the sectional area of the electroslag casting crystallizer. A plurality of electrode channels are distributed along the section of the electroslag casting crystallizer in a dispersed mode, the consumable electrodes conduct electroslag casting synchronously, molten metal formed by melting of the consumable electrodes penetrates t