JP2001286972A - Hot forging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot forging method having high heat efficiency without heating a forging stock in a heating furnace. SOLUTION: In the hot forging method to die forge a heated forging stock, the forging stock is die forged during cooling after rough forging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot forging method for forging and stamping a heated forging material.

[0002]

2. Description of the Related Art Generally, when forming a forged part for an automobile made of an aluminum alloy, a material of a continuous cast round bar having a length of about 4 meters is cut into a length corresponding to the shape of the product to form a forging material. Then, after holding the forging material in a heating furnace heated to about 450 ° C. for a certain period of time, the material was quickly taken out of the heating furnace to perform forging stamping. Further, the forged die was subjected to deburring, and the product was separated from the burr and then subjected to a solution heat treatment. In addition, burrs were collected by bullion traders and others.

However, in such a case, the forging material is obtained by cutting a round bar, and the cross-sectional shape of the material is circular regardless of the shape of the product to be formed. The number of hits was sometimes increased. In addition, a heating furnace for heating the forging material is required, and the forging material taken out of the heating furnace is cooled because forging die must be completed in a certain temperature range. In order to predict the temperature, the set temperature of the heating furnace had to be increased in advance.

[0004]

SUMMARY OF THE INVENTION As described above, an object of the present invention is to provide a hot forging method which solves the above-mentioned disadvantages.

[0005]

According to the present invention, there is provided a hot forging method according to the present invention for achieving the above object. In a hot forging method of forging and stamping a material, the forging material is forged and stamped during cooling after casting.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the hot forging method of the present invention will be described below with reference to the drawings.

[0007] The forging material used in the present invention is initially
Continuously cast round bar whose alloy composition is silicon 0.4% by weight or less, iron
0.7 wt% or less, copper 5.0-6.0 wt%, zinc 0.3 wt% or less, lead 0.2-0.6 wt%, bismuth 0.2-0.6 wt%, other individual 0.05 wt% or less, other 0.15 wt% or less, balance aluminum (A2011 The alloy cast is a continuous cast round bar cut from a length of 4 m to about 40 cm, and heated to about 450 ° C., and is stamped by a forging press 1 as shown in FIG. After cooling, deburring
Separated into product and burr.

The burrs are collected, put into a melting furnace 2 and melted, and the temperature is raised to 720 ° C. ± 20 ° C. Further, the melt is transferred to the holding furnace 3, where degassing and deoxidizing are performed.

[0009] Further, as shown in FIG.
A hot water for supplying the molten metal 9 to a gate 8 provided outside the mold surface 7 of the mold 4 by arranging the mold surface 7 of the upper mold 5 and the lower mold 6 of the aluminum alloy mold 4 together. The pool 10 is disposed in the receiving portion 11 so as to be separable, and the mold 4 is a tilting casting device 13 that can tilt at a substantially right angle by the tilting shaft 12.

[0010] Forging material 1 formed by the mold 4
As shown in FIG. 3, the shape 4 is a structure in which a substantially prismatic non-forged portion 16 is integrally connected to a main body of a cylindrical forged portion 15. The reason that the non-forged portion 16 is prismatic is that when the main forging material 14 is set on the die of the forging press 1, the main material 14 is hard to rotate, and the set position of the main material 14 is fixed. This is because it can be done.

As shown in FIG. 2, the basin 10 is separable from the receiving part 11 attached to the mold 4, and draws the molten metal in the holding furnace 2 as a ladle and receives the molten metal in the receiving furnace. Conveyed to section 11. In addition, mold 4 uses molten metal 9
Before pouring into mold 4, raise the temperature of mold 4 to 250 ℃ ± 20 ℃
Adjust it to

When the basin 10 is set in the receiving section 11, the basin 10 starts to tilt about the tilting shaft 12 together with the mold 4, and the basin 10 is tilted from the horizontal state to the vertical state. The molten metal 9 in the 10 penetrates into the prismatic cavity 17 near the gate 8 from the gate 8 and further into the cylindrical cavity 18 molded at the back, and the columnar cavity 18 which becomes the forged part 15, and A prismatic cavity that becomes the non-forged part 16
When the molten metal 9 is filled in the basin 17 and almost filled up to the vicinity of the gate 8, the molten metal 9 in the basin 10 becomes empty (about 22 seconds during this time).

At this time, since the mold 4 is made of an aluminum alloy having a high thermal conductivity, the molten metal filled in the cylindrical cavity 18 which becomes the forged portion 15 drastically removes heat from the mold surface. The so-called directional solidification is performed within a short time from the outside to the center of the cylindrical forged portion 15.

In addition, the mold cutting surface 7 is held for about 2 seconds in a vertical state. At this time, from the molten metal filled into the prism-shaped non-forged part 16, to the cylindrical forged part 15 which is rapidly solidified and the volume is contracted, the high-temperature molten metal is filled from above,
All melts are completely solidified. Therefore, the prismatic cavity 17 serves as a feeder.

The mold 4 is returned to the original horizontal state in about 10 seconds from the state in which the mold surface 7 is in the vertical state, and the upper mold
The mold 5 and the lower mold 6 are released, and the forging material 14 is taken out of the mold 4 by the transfer robot 19 as shown in FIG.

The removed forging material 14 is immediately conveyed to the forging press 1 by the transfer robot 19, and cooled to the temperature of 450 ° C. ± 20 ° C. of the forging material 14 itself after casting. Is stamped.

After the stamped product is cooled,
The burrs are separated by 20 and T6 treatment is performed by the heat treatment furnace 21. On the other hand, the burrs are collected again, put into the melting furnace 2 and stamped by the forging press 1 in the same process as described above.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a forging material recycling method according to the present invention will be described below. As shown in Table 1, the forging material used in the examples is A20 of Japanese Industrial Standards (JIS4040).
11 alloy, the alloy component of which is silicon 0.4% by weight or less,
0.7% by weight or less iron, 5.0-6.0% by weight copper, 0.3% by weight zinc
Hereinafter, 0.2-0.6% by weight of lead, 0.2-0.6% by weight of bismuth,
Other individual 0.05 wt% or less, other total 0.15 wt% or less,
The balance is aluminum.

The material for forging was made from a 4 m continuous cast
0 cm and cut by a forging press 1 in a state of being heated to 450 ° C. (Comparative Example) and a forging material recycling method according to the present invention described in the above-mentioned embodiment of the present invention. This embodiment will be described in comparison with this embodiment. In each of the comparative example and the present example, T6 treatment was performed after the die was stamped by the forging press.

Table 1 shows alloy components of the comparative example after the T6 treatment and the present example. In both the present example and the comparative example, the alloy components satisfy the specified values.

[0021]

[Table 1]

Next, Table 2 shows the mechanical properties of the comparative example after the T6 treatment and this example. In this example, the tensile strength and the proof stress are improved by about 0.5% as compared with the comparative example.
Further, in the present embodiment, the elongation is improved by about 23% as compared with the comparative example.

[0023]

[Table 2]

[0024]

According to the hot forging method according to the present invention, since the forging material is forged and stamped during cooling after casting, heat during casting can be used. Therefore, a special heating furnace is required. Instead, it is possible to provide a hot forging method with good thermal efficiency.

In the hot forging method according to the present invention, the forging material is formed by casting, so that a forging material according to the product shape can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a hot forging method according to the present invention.

FIG. 2 is a casting apparatus for molding a forging material according to the present invention.

FIG. 3 is a perspective view of a forging material according to the present invention.

[Explanation of symbols]

 1 ・ ・ ・ Forging press 2 ・ ・ ・ Melting furnace 3 ・ ・ ・ Holding furnace 4 ・ ・ ・ Die 13 ・ ・ ・ Tilting caster 19 ・ ・ ・ Transfer robot 20 ・ ・ ・ Deburring machine 21 ・ ・ ・ Heat treatment Furnace

Claims (1)

[Claims] 1. A hot forging method for forging and stamping a heated forging material, wherein the forging material is forged and stamped during cooling after casting.