JPH0699775B2 - Precision casting method for iron-manganese-aluminum alloy - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for precision casting of a precision casting such as a metal head of a golf club, which is a thin casting having a complicated shape and a non-uniform thickness, using an iron-manganese-aluminum alloy.

[0002]

2. Description of the Related Art Nickel-chromium (Ni-Cr) -based stainless steel is often used for precision castings such as metal heads of conventional golf clubs. Attempts have also been made to use an iron-manganese-aluminum alloy having high toughness, high mechanical strength, excellent corrosion resistance, and wear resistance.

[0003]

However, for example, a metal head of a golf club manufactured from the above-mentioned conventional nickel-chromium (Ni-Cr) type stainless steel lacks strength of a hitting surface for hitting a golf ball, There is a problem that the metal head may be damaged, the vibration absorption at the time of hitting is low, the hitting sound becomes loud, and the specific gravity becomes large. Further, regarding the iron-manganese-aluminum alloy, the above-mentioned excellent properties are known by various studies, but on the other hand, the thermal expansion coefficient is large, the thermal conductivity is low, and when the alloy is melted, it is easily oxidized. It also has an impediment factor in casting manufacturing such as segregation of brittle structure in the grain boundaries. Regarding the influence of material composition, casting process control and heat treatment of casting on the product characteristics in the casting technology of this alloy. There is a problem that the casting technology has not been established yet because it has not been clarified yet.

In view of the above problems, the object of the present invention is complicated without impairing the excellent characteristics of the iron-manganese-aluminum alloy whose raw material price is lower than that of nickel-chromium (Ni-Cr) type stainless steel castings. It is an object of the present invention to provide a precision casting method for a thin-walled casting having a shape and a non-uniform sectional thickness of the casting.

[0005]

Means for Solving the Problems Iron-manganese-of the present invention
The precision casting method for an aluminum alloy has a composition of 0.5 to 2.0% by weight of carbon (C) and 25 to 20% of manganese (Mn).
36 wt%, aluminum (Al) 5-10 wt%, molybdenum (Mo) 0.5-1.5 wt%, balance iron (F
In the manufacturing process of the iron-manganese-aluminum alloy precision casting which is e), the above-mentioned alloy rapidly heated and melted to 1400 to 1420 ° C is cast into a ceramic mold preheated to 1300 to 1320 ° C, and the ceramic mold is used. Welding current of 40-
Welded at 60 amps, the welded casting was solution-treated at 1030 to 1050 ° C for 1 to 2 hours, and then aged at 450 to 550 ° C for 1 to 2 hours. The ceramic mold had a thickness of about 5 mm and a raw material. Mold strength is 350 psi, fired body strength is 460 p
si and air permeability of 6.5 × 10 ^-3 cm ³ / sec · cm ² · aq
It is characterized by being.

[0006]

In the method of precision casting of iron-manganese-aluminum alloy according to the present invention, the composition is 0.5 to 2.0% by weight of carbon (C), 25 to 36% by weight of manganese (Mn), and 5% of aluminum (Al). -10 wt%, molybdenum (Mo) 0.5-
1.5% by weight, the alloy raw material that is controlled and blended so that the balance is iron (Fe) is rapidly melted by heating to 1400 to 1420 ° C and cast into a ceramic mold preheated to 1300 to 1320 ° C. As a result, the molten alloy water flows well into this mold, and segregation can be prevented. And, the ceramics mold has a thickness of about 5 mm and a green strength of 350 psi,
Fired body strength is 460 psi and air permeability is 6.5 × 10
^By setting ^-3 cm ³ / sec · cm ² · aq, it is possible to prevent cracking or cracking during solidification of the casting. Then, various cast parts obtained by casting are welded by TIG welding at a welding current of 40 to 60 amperes, whereby cracks, cracks and pinholes can be prevented in the vicinity of welding. And the welded casting is 1030 ~ 1050 ℃
The formation of an oxide layer on the surface of the casting is suppressed by performing the solution treatment for 1 to 2 hours, and the high-strength casting can be obtained by performing the aging treatment at 450 to 550 ° C. for 1 to 2 hours.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A metal head of a golf club according to an embodiment of the precision casting method for iron-manganese-aluminum alloy of the present invention will be described with reference to FIGS.

Reference numeral 1 denotes a metal head of a golf club. This metal head 1 has a connecting portion 2 having an opening for fitting a shaft of a golf club (not shown) and protruding rearward, and a right side surface portion thereof has a substantially hemispherical shape and a curved surface thereof. The main body portion 3 reaching to the front, and the left side surface portion are formed of, for example, a concave arc-shaped striking surface 4 for striking a golf ball (not shown), and a bottom portion 5 in contact with the ground (not shown).

Next, a method of manufacturing the metal head of the above embodiment will be described.

A thickness of about 5 mm, a green strength of 350 psi, a fired body strength (dry strength) of 460 psi, and an air permeability of 6.5 × 10 ⁻³ cm ³ / sec · cm ² · aq were baked by a shell molding method. Ceramic molds made by tying 1300 ~
Keep heating at 1320 ℃. Separate composition is carbon (C)
0.5-2.0 wt%, manganese (Mn) 25-36 wt%, aluminum (Al) 5-10 wt%, molybdenum (Mo) 0.5-1.5 wt%, balance iron (Fe) The alloy raw materials are blended under the control.

When the alloy raw material is heated and melted, scum is generated by the oxidation of the molten raw material, and defects such as segregation and cracks are prevented during the casting and slow cooling in the ceramics mold to prevent the molten raw material from being melted. In order to be able to flow into the mold, when it reaches 1200 ° C, it is heated and melted to 1400 to 1420 ° C in about 20 to 25 minutes by rapid heating, and when it reaches 1400 to 1420 ° C, it is immediately added to the ceramic mold. Cast in.

When welding the peripheral portion of the bottom portion where the body portion 3 and the bottom portion 5 that have been solidified by cooling are joined together and welded with a welding rod made of stainless steel, manganese steel or the like, cracks and cracks are formed in the vicinity of the welded portion. Since pinholes are generated, welding is performed by TIG welding while controlling the welding current to be 40 to 60 amps.

When heat-treating the metal head 1 after welding, as shown in FIGS. 5 and 6, it is heat-treated by the nitrogen cooling method of vacuum furnace heat treatment and the nitrogen cooling method of continuous furnace heat treatment such as tunnel furnace. The metal head 1
The surface oxide film thickness is thin, and the Rockwell hardness is HRC32 to 36 in a vacuum furnace and HRC28 to 32 in a continuous furnace, but the tenacity and mechanical strength, which are toughness, are weak, so as shown in FIG. In a high temperature continuous furnace maintained at 900 ° C. or higher, rapid heat treatment is performed at 1030 to 1050 ° C. for 1 to 2 hours, water quenching by water cooling or quenching by an oil cooling method to obtain Rockwell hardness of HRC 8-12. Solution treatment is performed so that

After chamfering and drilling, 45
It heat-processes at 0-550 degreeC for 1-2 hours, and aged so that a Rockwell hardness may be set to HRC28-36.

In the metal head 1 after the aging treatment, the oxide remaining on the surface is removed by sand blasting or shot blasting, and a coating material is applied and baked so that the thickness of the dry coating becomes 3 to 5 μm.

The iron-manganese-aluminum alloy contains carbon (C) of 1.5 to 2.0% by weight and manganese (M).
The composition of n) 32 to 36% by weight, aluminum (Al) 6 to 8% by weight, molybdenum (Mo) 1.0 to 1.5% by weight, and balance iron (Fe) is preferable.

Next, the ceramic mold will be described.

The ceramic mold must be kept at a high temperature in order to prevent scum and segregation in the molten alloy raw material water, and must have fire resistance up to a high temperature. Further, this ceramic mold has a property of crushing before the metal head 1 is cracked or cracked due to the cooling shrinkage stress generated during the slow cooling of the iron-manganese-aluminum alloy having a large thermal expansion coefficient and a low thermal conductivity. There is a need. Therefore, this ceramic mold has a zircon powder 30 whose first layer is 0.044 mm or less.
˜70% by weight, for example, about 25% by weight of silica powder such as silica sand and about 25% by weight of silicic acid sol, and the second layer is 0.07% by weight.
45-55% by weight of margrain powder of 4 mm or less, about 4% by weight of graphite such as scaly graphite of 0.074 mm or less, about 25% by weight of silica powder, about 25% by weight of silicic acid sol, 0.25 to 0% 0.5-80 mm chamotte, the third layer of which is 0.074 mm or less of 45-80% by weight of margrain powder, about 4% by weight of the graphite, about 25% by weight of the silica powder, about 25% by weight of silicic acid sol, and an appropriate amount of 0. 0.25 to 0.5 mm
The fourth layer comprises 45 to 80% by weight of the margrain powder of 0.074 mm or less, about 6% by weight of the graphite, about 25% by weight of the silica powder, about 25% by weight of silicic acid sol, and a proper amount of 0. It consists of chamotte of 5 to 1.0 mm,
The fifth layer is the above-mentioned 0.074 mm or less margrain powder 45
.About.80% by weight, about 6% by weight of the graphite, about 25% by weight of the silica powder, and about 25% by weight of silicic acid sol. Five layers of fire resistance so that the first layer is on the casting surface side in contact with the molten alloy. It is particularly preferred that it is composed of a slurry.

Next, the operation of the above embodiment will be described.

The composition is 0.5 to 2.0% by weight of carbon (C), 25 to 36% by weight of manganese (Mn), 5 to 10% by weight of aluminum (Al), and 0.5 to 0.5% of molybdenum (Mo).
1.5% by weight, the alloy raw material that is controlled and blended so that the balance is iron (Fe) is rapidly melted by heating to 1400 to 1420 ° C and cast into a ceramic mold preheated to 1300 to 1320 ° C. By this, generation of scum due to oxidation of the metal at high temperature can be prevented, the molten alloy hot water can satisfactorily flow into this mold, and segregation can be prevented. And, the ceramic mold has a thickness of about 5 mm and a green strength of 350 ps.
i, fired body strength is 460 psi and air permeability is 6.5 ×
By setting 10 ⁻³ cm ³ / sec · cm ² · aq, it is possible to prevent cracking or cracking during solidification of the main body portion 3 and the bottom portion 5. Then, the main body portion 3 and the bottom portion 5 obtained by casting are tied with a welding current of 40 to 60 amperes.
By welding by G welding, it is possible to prevent cracks, cracks and pinholes in the vicinity of welding. Then, the welded metal head 1 is heated to 900 ° C. as shown in FIG.
After heat treatment at 1030 to 1050 ° C for 1 to 2 hours, water quenching or oil cooling is carried out suddenly to carry out solution treatment so that the hardness becomes HRC8-12. A metal head 1 having a low hardness, suppressing the formation of an oxide layer on the surface of the casting, and having an average compressive strength of 2100 kg / mm ² or more and having good tenacity and mechanical strength is obtained at 450 to 550 ° C. By performing the aging treatment for 2 hours, a high-strength metal head 1 having a high hardness can be obtained.

Table 1 shows the conventional nickel-chromium (Ni-C).
The characteristic table of the metal head by r) type | system | group stainless steel and the metal head 1 by the precision casting method of the iron-manganese-aluminum alloy of this invention is shown.

[0022]

[Table 1] From Table 1, comparing the metal head 1 according to the precision casting method for iron-manganese-aluminum alloy of the present invention with the conventional metal head made of nickel-chromium (Ni-Cr) stainless steel, according to the present invention, iron-manganese- It is clear that the hardness of aluminum alloy, which is a characteristic of aluminum alloy, is high, and the tenacity and mechanical strength are strong, and it is possible to manufacture the metal head 1 that is light and excellent in vibration absorption and has a low impact sound.

The metal head 1 which was the product after baking and coating was also found to have corrosion resistance for 24 hours or longer by the salt spray test of 5% saline solution.

[0024]

According to the method for precision casting of iron-manganese-aluminum alloy of the present invention, the composition is 0.5 (C).
~ 2.0 wt%, manganese (Mn) 25-36 wt%,
Aluminum (Al) 5 to 10% by weight, molybdenum (M
o) Promptly 1400 to 1420 ° C for alloy raw materials that are controlled and compounded so that the balance is 0.5 to 1.5% by weight and the balance is iron (Fe).
By melting it by heating and casting it in a ceramic mold that has been preheated to 1300 to 1320 ° C., the molten alloy water flows well into this mold and segregation can be prevented. Then, the ceramics mold had a thickness of about 5 mm and a green mold strength of 3
By setting the pressure to 50 psi, the fired body strength to 460 psi, and the air permeability to 6.5 × 10 ⁻³ cm ³ / sec · cm ² · aq, it is possible to prevent cracking or cracking during solidification of the casting. The welding current of the various cast parts obtained is 40 to
Welding by TIG welding at 60 amps can prevent cracks, cracks and pinholes near the weld. And, the welded casting is 1 ~ 10 at 1030 ~ 1050 ℃
The solution treatment for 2 hours suppresses the formation of an oxide layer on the surface of the casting, and the aging treatment at 450 to 550 ° C. for 1 to 2 hours makes it possible to obtain a high-strength casting. From these facts, an iron-manganese-aluminum alloy having high toughness, strong mechanical strength, excellent corrosion resistance, and wear resistance can be obtained by using nickel-chromium (Ni-Cr) -based stainless steel without impairing these characteristics. It is possible to perform precision casting of a thin-walled casting having a complex shape of an iron-manganese-aluminum alloy, which has a higher impact strength, a lower specific gravity, and a lower raw material cost than the manufactured casting, and has a non-uniform cross-sectional thickness.

[Brief description of drawings]

FIG. 1 is a front view of a metal head of a golf club according to an embodiment of a precision casting method for iron-manganese-aluminum alloy of the present invention.

FIG. 2 is a side view of the above.

FIG. 3 is a rear view of the above.

FIG. 4 is a graph showing the conditions of the solution treatment described above.

FIG. 5 is a graph showing conditions of an example of a conventional solution treatment.

FIG. 6 is a graph showing conditions of another example of the above.

[Explanation of symbols]

 1 Metal head which is a welded casting 3 Main body which is a plurality of casting parts

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C21D 9/00 Z 9352-4K C22C 38/00 302 A 38/12

Claims (1)

[Claims] 1. The composition is such that carbon (C) is 0.5 to 2.0 wt%, manganese (Mn) is 25 to 36 wt%, aluminum (Al) is 5 to 10 wt%, and molybdenum (Mo) is 0.5 to.
In the manufacturing process of precision casting of iron-manganese-aluminum alloy with 1.5% by weight and balance iron (Fe), the above alloy which was rapidly heated and melted at 1400 to 1420 ° C was previously prepared.
It is cast into a ceramic mold that has been preheated to 1300 to 1320 ° C, and a plurality of casting parts obtained with this ceramic mold are
The welding current is 40 to 60 amperes by G welding, and the welded casting is subjected to solution heat treatment at 1030 to 1050 ° C for 1 to 2 hours and then aged at 450 to 550 ° C for 1 to 2 hours. Has a thickness of approximately 5 mm and a raw strength of 35
Precision casting method of iron-manganese-aluminum alloy, characterized in that 0 psi, fired body strength is 460 psi, and air permeability is 6.5 × 10 ⁻³ cm ³ / sec · cm ² · aq.