Online forced cooling method and device for extrusion die

Abstract

The invention discloses an online forced cooling method and device for an extrusion die, used for metal hot extrusion forming. An annular straight slot is machined between a discharging hole of the extrusion die and a pad special for the die around the contour of a main reaction shape of the discharging hole of the extrusion die; a gas pipe is laid in the annular straight slot; cooling inert gasesare introduced into the gas pipe; the cooling gases are ejected onto a die working length and the surface of an extrusion material via tiny outlet holes in the gas pipe. According to extrusion forming production of aluminum and magnesium alloys and other products having low quenching temperature sensitivity, high-pressure forced cooling can be conveniently performed at the extrusion outlet, the extrusion material is subjected to online quenching heat treatment, and the corresponding mechanical property requirements can be met; grain coarsening caused by secondary crystallization is avoided, so that the surface quality meets the requirements, and the surface is bright; the defects in the size, shape, structure and the like of the extrusion material due to extremely high metal temperature fluctuation in the hot extrusion process can be overcome; the extrusion speed is effectively improved, and the production efficiency is improved by 10% or higher.

Description

technical field [0001] The invention relates to the field of metal hot extrusion forming, in particular to an online forced cooling method and device for an extrusion die. Background technique [0002] During the hot extrusion forming process of metal materials, due to the friction and deformation work converted into heat, the temperature of the mold rises, the bonding force between the working belt of the mold and the metal material increases, and the adhesion force everywhere on the working belt of the mold increases. Unbalanced, resulting in uneven scratches on the metal at the outlet of the working belt, which seriously affects the surface quality of the extruded material, especially for extrusion dies with complex structures, large loads, fast extrusion speeds or high-strength extrusions For metal materials, the temperature rise of the extruded profile reaches its recrystallization temperature at the exit of the mold, and secondary crystallization is prone to occur, m...

AI Technical Summary

Problems solved by technology

[0002] During the hot extrusion forming process of metal materials, due to the friction and deformation work converted into heat, the temperature of the mold rises, the bonding force between the working belt of the mold and the metal material increases, and the adhesion force everywhere on the working belt of the mold increases. Unbalanced, resulting in uneven scratches on the metal at the outlet of the working belt, which seriously affects the surface quality of the extruded material, especially for extrusion dies with complex structures, large loads, fast extrusion speeds or high-strength extrusions For metal materials, the temperature rise of the extruded profile reaches its recrystallization temperature at the exit of the mold, and secondary crystallization is prone to occur, making the surface prone to coarse grains and forming a coarse-grained layer, resulting in a decrease in the strength of the profile, and even causing The surface of extruded products is severely oxidized, black spots are formed, and there are serious defects such as overburning. At present, the methods to solve the above problems are mostly adopted: one is to reduce the extrusion speed, but it affects production efficiency; the other is to improve the structure of the mold itself to reduce extrusion. Forming resistance, reducing the heat caused by friction, but the difficulty of mold manufacturing technology increases and the production cost increases

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