Large-scale electrical upsetting method and anvil electrode for gradient change of electrode resistivity

Abstract

The invention discloses a large-scale electric upsetting method with a gradient change in electrode resistivity. Under the action of electric upsetting, the rod blank gradually increases radially to form a bulb of garlic; when the bulb of garlic radially increases to the center of the bulb of garlic, it will produce an axial sinking trend When the size of the garlic head is at this time, the annular region where the edge of the garlic is in contact with the anvil electrode is used as the ring-shaped suppression zone on the anvil electrode; the resistivity of the ring-shaped suppression zone is increased to locally reduce the current density; During the process, the current density of the blanks that continuously reach the annular suppression zone decreases to lower the temperature, thereby inhibiting the fluidity of the ring part of the garlic corresponding to the ring suppression zone, and then inhibiting the ring part of the garlic corresponding to the ring suppression zone to drive the center of the garlic to carry out The trend of axial flow finally makes the sinking trend of the center of the garlic suppressed. The invention solves the problem that the end surface sag cannot be improved by changing the electric upsetting loading parameters, and improves the uniform refinement degree of garlic crystal grains while improving the end surface sag.

Description

technical field [0001] The invention belongs to the field of metal plastic forming in material processing engineering. Background technique [0002] The electric upsetting process satisfies the needs of local accurate aggregation of long rod parts with super large and variable cross-sections. The electrothermal upsetting process couples the three physical fields of electrothermal force, passes current between the anvil electrode and the clamping electrode, heats through the contact resistance and its own resistance, and applies a certain upsetting force on the right end of the billet, and the billet at the cold end is sent to It enters the heating area between the anvil electrode and the clamping electrode, so that the blank gradually undergoes plastic deformation to complete local aggregation. Since the plastic deformation area is strictly restricted in the heating area, a workpiece with a large amount of deformation can be quickly realized. [0003] When electric upsetti...

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Problems solved by technology

[0004] Aiming at the deficiencies of the above-mentioned technologies, the present invention provides a large-scale electrical upsetting method with a gradient change in electrode resistivity, which solves the problem that the end surface depression cannot be improved by changing the loading parameters of the electrical upsetting

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