JPS5944131B2 - Indirect extrusion equipment for metal materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for indirect extrusion of metal materials, and particularly to an apparatus for preventing extrusion defects caused by metal flow during extrusion processing.

Indirect extrusion of metal materials is performed by inserting a metal material billet 3 heated to a high temperature into a cylindrical pressure vessel whose one end is sealed by providing a closing plate 2 at one end of a cylindrical container 1, as shown in FIG. A stem 4 is press-fitted from the end, a metal billet 3 is pressurized by a die holder 5 provided at the tip of the stem 4, and a die 6 attached to the die holder 5, and the metal material is extruded into a predetermined shape through the die 6. So, the container
Since the inner peripheral surface of billet 1 and the outer peripheral surface of billet 3 do not move relative to each other, by providing an appropriate gap between the inner peripheral surface of container 1 and die holder 5, the surface layer of billet 3 can be left intact as a shelf.

According to this device, it is possible to prevent oxidized scale from flowing into the extruded material from the billet surface layer to some extent due to metal flow during extrusion.

However, since the contact surfaces between the end face of the billet and the die and die holder are relatively slippery, the oxide scale adhering to the end face of the billet flows into the extruded material in the early stage of extrusion.

This flowing oxide scale causes extrusion defects on the outer surface of the extruded material or at a shallow portion below the outer surface.

In view of this, and as a result of various studies, the present invention has been developed to prevent the oxidized scale adhering to the end face of the billet from flowing into the extruded material, and to completely prevent the oxidized scale adhering to the outer peripheral surface of the billet from flowing into the extruded material, thereby improving the quality of the extruded material. We have developed an indirect extrusion device for metal materials that can improve the performance of metal materials.The metal material billet is heated to a high temperature in a cylindrical pressure vessel with one end sealed, and a die holder with a die attached is pressed through the opening at the other end. In a device that extrudes a metal material into a predetermined shape through a die, there is a diameter of 5 to 45 mm around the extrusion hole on the pressing surface of the die.
It is characterized by having a conical surface protruding at an inclination angle of .degree.

That is, the present invention, as shown in FIG. 2, inserts a billet of metal material 3 heated to a high temperature into a cylindrical pressure vessel whose one end is sealed by providing a closing plate 2 at one end of a cylindrical container 1, The die holder 5 provided at the tip of the stem 4 pressurizes this from the other end, and the surface of the die 6 that contacts the billet 3 has 5 to 45
A conical surface 6b protruding at an inclination angle θ of °C is provided.
The billet 3 is pressurized by the conical surface 6b, the outer peripheral layer of the billet 3 is left as a shelf on the inner peripheral surface of the container 1, and the metal material is extruded into a predetermined shape through the extrusion hole 6a of the die 6. Either the relative slippage at the contact surface between the die 6 and the die holder 5 disappears, or metal flow begins to flow out from the gap provided between the inner surface of the container 1 and the die holder, and the oxidation adhering to the outer circumferential surface of the billet 3 is removed. This prevents not only scale but also oxidized scale adhering to the end face from flowing into the extruded material, significantly improving the quality of the extruded material.

Therefore, the inclination angle of the conical surface is set to 5 to 45 degrees because
Below 5°, the effect is small, and as the angle increases, the effect increases; when the angle is over 10', there is no metal flow toward the die extrusion hole on the end face of the billet, and 30°
If the angle exceeds 45°, metal flow will occur toward the gap between the inner circumference of the container and the die holder, and if the angle exceeds 45°, the amount of shell remaining on the inner periphery of the container will increase, reducing the yield. To achieve a good yield and prevent oxide scale from flowing into the stamped material, the inclination angle of the conical surface should be set to 10.
It is desirable to set the angle to ~30°.

In addition, it is desirable that the gap between the inner circumference of the container and the die holder be 0.5 to 3 mm; if the gap is less than 0.5 mm, metal flow toward the die extrusion hole on the end face of the billet will occur.
If it exceeds mm, the amount of shell remaining on the inner peripheral surface of the container will increase and the yield will decrease.

Although we have described an example in which a conical surface is provided on the entire billet contact surface of the die and the die holder, this is not limiting.If a conical surface is provided on the billet contact surface of the die, the billet contact surface of the die holder The surface may be flat.

Examples of the present invention will be described below.

As shown in Fig. 2, a protruding conical surface is provided on the billet contact surface of the die and the die holder, and the inclination angle of the conical surface is changed to convert a copper billet with an outer diameter of 300iH and a length of 1000mm into a round bar with an outer diameter of 501m. The defects in the extruded material and the metal flow near the end face of the billet were investigated.

The results are shown in Table 1. Note that the gap between the inner peripheral surface of the container and the die holder was 1 mm.

As is clear from Table 1, when extruded using the conventional device/16.1, which has a flat contact surface with the billet, the metal flow at the end of the billet flows into the die extrusion hole, and there are many lines in the extruded material. A defect occurred.

In contrast, in the device of the present invention in which a protruding conical surface was formed on the contact surface of the die and die holder with the billet, inflow toward the inner circumference of the container was observed when the inclination angle was 45°/16.5. However, other than that, no slippage was observed at the die contact area.

In addition, when the protrusion angle was 5°/162, minute defects were observed in the extruded material, but no defects were observed in other cases.

Further, in the comparative device/I66 with an inclination angle of 60°, no defects were observed in the extruded material, but the billet end flowed toward the inner circumferential direction of the container significantly, resulting in a decrease in yield.

As described above, the present invention can completely prevent the oxidized scale attached to the outer circumferential surface and end face of the billet from flowing into the extruded material, without significantly reducing the yield, and improve the quality of the extruded material. This has a remarkable effect.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of a conventional indirect extrusion device, FIG. 2 is a side sectional view showing an embodiment of the indirect extrusion device of the present invention,
FIG. 3 is an enlarged sectional view of the main part in FIG. 2. 1... Container, 2... Sealing plate, Total... Billet, 4... Stem, 5... Die holder, 6... Die, 7... Shell.

Claims (1)

[Claims] 1 In a cylindrical pressure vessel with one end sealed, a die holder with a die attached is press-fitted into a billet of metal material heated to high temperature from the opening at the other end, and the metal material is extruded into a predetermined shape through the die. An indirect extrusion device for metal materials, characterized in that a conical surface protruding at an inclination angle of 5 to 45 degrees is provided around the extrusion hole on the pressing surface.