TWI406958B - Fe-cr-ni alloy of golf club head - Google Patents

Abstract

A Fe-Cr-Ni Alloy of a Golf Club Head has 11-13 wt% of Cr, 4.5-5.5 wt% of Ni, 0.15-0.25 wt% of N and 0.05-0.15 wt% of C, and the balance is mainly Fe and trace impurities. The Fe-Cr-Ni Alloy can provide excellent mechanical properties including a tensile strength greater than 180 ksi, a yield strength greater than 165 ksi and an elongation percentage greater than 25 %, while the alloy is martensitic-ferritic stainless steel suitably applied to forging or casting golf iron heads for enhancing the tensile strength, elongation percentage, corrosion resistance, forging processing property and casting property of the golf iron heads.

Description

Golf club head iron chrome-nickel alloy

The present invention relates to an iron-chromium-nickel alloy for a golf club head, and more particularly to an iron-chromium-nickel alloy for a golf club head suitable for forging or casting a golf iron head and capable of improving its mechanical strength, ductility and rust resistance.

"Alloy" means a mixture of metal-characteristics formed by doping or adding one or more other metals or non-metals in a primary metal. When a pure metal is alloyed by adding other metals or non-metals for special purposes, its properties will also change, such as a decrease in melting point, an increase in strength, a decrease in ductility, an increase in electrical resistance, and a decrease in thermal conductivity. Improvement in heat treatment performance, change in corrosion resistance, and magnetic change. Since pure metals are alloyed, their mechanical, physical and chemical properties are improved. Therefore, with the design of machinery and appliances, appropriate alloying elements can be selected and their contents, manufacturing procedures, processing procedures, heat treatment procedures, It is formulated into a combined alloy material.

In recent years, the trend of golf has become more and more popular, and athletes of all ages want to have a set of golf equipment to experience golf. In general, a complete golf club includes several clubs for different purposes, and each club has a club head made of various alloy materials. The clubs can usually be divided into the following types: wood poles 3 to 5 (wood), 7 to 8 irons, 1 lifter (PW), 1 sand pit (SW), and 1 putter. The head of the wood rod generally has a hollow shell shape, and mainly comprises a main shell, a striking panel, a bottom surface and a top cover, and the components are usually made of different alloys or carbon fiber materials, and then assembled into the same. Wooden club head. The irons, the lifting rods and the heads of the sand rods are all iron heads. The head of the iron rod is generally a solid plate with a thin upper and a lower thickness, and mainly includes a head body, a striking panel and a weight member, and each member may be integrally formed from the same alloy material; or different The alloy materials are separately fabricated and assembled into the iron head. In addition, in order to make the iron head have the advantages of the long-distance strike of the traditional wood pole and the accuracy of the iron rod, the iron head is also made into a hollow.

At present, the manufacturing method of the golf iron head is mainly for the precision dewaxing casting method and the forging processing method, and there are also those who use the surface plating or the panel processing. Referring to Fig. 1, there is disclosed a comparison table of characteristics of golf iron heads manufactured by the industrial precision dewaxing casting method and the forging processing method. Overall, the cost of the precision dewaxing casting process is relatively low, but the forging process has many advantages. The difference in characteristics between the precision dewaxing casting method and the forging processing method is the result of the difference in the alloy materials and processing conditions applicable to the two methods.

Please refer to Fig. 2, which shows a comparison of the mechanical properties of the alloy materials used in the precision dewaxing casting method and the forging processing method of the current golf iron head. When analyzing the mechanical properties of the stainless steel alloy materials, it can be found that the casting stainless steel alloy material has a relief strength of about 94 ksi or less, a tensile strength of about 123 ksi or less, and an elongation of about 41% or less; The lodging strength is about 93 ksi or less, the tensile strength is about 121 ksi or less, and the elongation is about 64% or less. In general, the mechanical strength of the stainless steel alloy material for casting is better, and the stainless steel alloy material for forging has higher requirements for elongation and corrosion resistance.

Furthermore, the current design direction of the golf club head tends to: (1), the ball head is enlarged to increase the sweet spot of the club head to improve the successful hitting rate and increase the hitting distance; (2), low Focus on the ball to achieve stable swing and better hitting point position, and increase the torsional inertia, improve the hitting distance; (3), low air resistance and concave back hit panel design to achieve a stable swing Sexuality and better hitting point position, and reduce the torsional energy loss, reduce the drag coefficient and change the position of different center of gravity and sweet spot.

Overall, in the case of golf iron heads, under the fixed weight limit, it is mainly developed to seek materials with appropriate mechanical strength and high ductility, such as 17-4PH stainless steel, 431 stainless steel, 255 stainless steel, N50 stainless steel, N60 stainless steel or iron-manganese-aluminum alloy, etc., its role is to expand the sweet zone of the ball, reduce the center of gravity of the ball and strengthen the impact panel, in order to achieve successful hitting and good hitting point, increase the torsional inertia, improve the angle of the flying ball, etc. .

In the case of golf irons, although the low center of gravity, low air resistance and enhanced impact panels can achieve the goals of successful hitting and good hitting, increasing the torsional inertia and increasing the hitting distance, the shape of the golf iron head itself changes more. Therefore, the alloy material used to make the iron head must have both appropriate strength and high ductility, as well as corrosion resistance. However, the current industrial stainless steel alloy materials do not fully meet all the performance requirements of the iron head. Taking stainless steel as an example, although it has corrosion resistance and strength, it is much more than the iron head, and its elongation or toughness is not ideal. In the case of AISI304 stainless steel, the tensile strength is about 70 to 75 ksi, although the elongation is about 40 to 60%, which can increase the handling of the ball. However, after the ball is used for a period of time, the angle of the face changes. That is to say, its strength is still insufficient. Therefore, S25C forged soft iron (both 75 to 85ksi tensile strength and 30 to 35% elongation) is still the best material for making iron heads, but the corrosion resistance after forging is not enough.

According to the current experience of golf club head manufacturing, the tensile strength of the best iron head alloy material should theoretically be about 1.0 to 1.2 times that of forged soft iron, or 1.1 to 1.3 times of 304 stainless steel, that is, the lodging strength must be at least 50 to 75 ksi, the tensile strength should be at least 80 to 100 ksi, and the elongation should be more than 40% and the higher the better, and the corrosion resistance is required. If the above conditions are met, a golf iron head or hollow iron head with the best impact performance can be produced.

Please refer to Figure 3 for the basic structure distribution of the iron-chromium-nickel stainless steel alloy series. In the past few decades, the iron-chromium-nickel alloy steel series has been extensively studied and discussed. It has been shown that iron-nickel-nickel alloy steels can have high strength, high toughness, low temperature resistance, high temperature resistance and wear resistance, respectively, through different alloy designs. Characteristics, the main components are iron, chromium and nickel, in which the addition of chromium can increase the oxidation resistance and corrosion resistance of the alloy, while nickel The addition of elements stabilizes the Vostian iron phase or the Matian iron phase, making the alloy a face-centered cubic (FCC) structure at room or low temperature to improve the toughness of the iron-based alloy. The basic classification of iron-chromium-nickel alloy steel is as follows:

(1), Worthfield iron-based alloy steel: its microstructure is a complete FCC structure, the basic composition is: 16 to 26 wt% of chromium, 8 to 25 wt% of nickel, 0 to 6 wt% of molybdenum and 0.08 wt% or less Carbon; its typical mechanical properties range: tensile strength of about 60 to 80 ksi, relief strength of about 45 to 60 ksi, elongation of about 40 to 60%.

(2), ferrite iron alloy steel: its microstructure is a body-centered cubic (BCC) structure, the basic composition is: 12 to 19 wt% of chromium, 0 to 5 wt% of nickel, below 5 wt% Molybdenum and carbon of 0.25 wt% or less; typical mechanical properties range: tensile strength of about 60 to 100 ksi, relief strength of about 45 to 80 ksi, and elongation of about 20 to 30%.

(3), ferrite iron - Vostian iron alloy steel: its microstructure is FCC + (20 to 50wt%) BCC dual phase structure, the basic composition is: 18 to 27 wt% chromium, 4 to 7 wt% nickel 1 to 4 wt% or less of molybdenum and 0.05 wt% or less of carbon; typical mechanical properties range: tensile strength of about 100 to 120 ksi, relief strength of about 45 to 80 ksi, and elongation of about 25 to 40%.

(4), Ma Tian scattered iron alloy steel: its microstructure is the Ma Tian loose iron structure, the basic composition is: 11 to 18wt% chromium, 0 to 2wt% nickel, 2wt% or less molybdenum and 0.17wt% or less Carbon; its typical mechanical properties Surrounding: Tensile strength is about 150 to 200 ksi, relief strength is about 140 to 180 ksi, and elongation is about 10 to 15 wt%.

(5), Ma Tian loose iron - Worthfield iron alloy steel: its microstructure is Ma Tian loose iron + (0 to 20wt%) Worth iron biphasic structure, the basic composition is: 12 to 18wt% chromium, 4 to 6 wt% nickel, 1 to 2 wt% molybdenum and 0.10 wt% carbon; typical mechanical properties range: tensile strength of about 120 to 160 ksi, relief strength of about 100 to 140 ksi, and elongation of about 15 to 20%.

Please refer to Figures 2 and 3 again. In order to further improve the mechanical properties of the stainless steel alloy material of the golf iron head, the inventor of the present invention improved the design of an iron-chromium-nickel alloy (iron-11-13wt% chromium-4.5-5.5wt% nickel). ) to conduct research and analysis of mechanical properties. The results show that the iron-chromium-nickel alloy has a relief strength of about 165 ksi after 1 to 2 hours of heat treatment at 780 to 930 ° C, a tensile strength of about 180 ksi, and an elongation of about 25%, so that further design can be achieved. Compared with the control composition ratio, manufacturing process and microstructure of iron-chromium-nickel alloy, it can develop iron with high strength, greater than 165ksi, tensile strength greater than 180ksi, elongation greater than 25%, and high forging processability, casting properties and corrosion resistance. Chrome-nickel alloy for use in the manufacture of golf iron heads or hollow iron heads with better hitting effects.

In summary, the inventors have designed the iron-chromium-nickel alloy of the golf club head of the present invention by using the concept of alloy design and process treatment, which has (Masuda loose iron and 5 to 15 wt% granular dispersion of Worthfield) Iron) characteristics of two-phase microstructure, while using appropriate process processing (low frequency shock Swing or heat treatment) to make the structure fine, so that the iron-chromium-nickel alloy has mechanical properties with a relief strength greater than 165 ksi, a tensile strength greater than 180 ksi, and an elongation greater than 25%, and has high forging processability, casting properties and resistance Corrosive properties. Therefore, compared with the conventional stainless steel alloy, the iron-chromium-nickel alloy of the invention is more suitable for making a golf iron head or a hollow iron head, and can make the iron head have higher ductility, rust resistance and forging processability. advantage.

The main object of the present invention is to provide a golf club head iron chromium nickel alloy comprising 11 to 13 wt% of chromium, 4.5 to 5.5 wt% of nickel, 0.15 to 0.25 wt% of nitrogen and 0.05 to 0.15 wt% of carbon. The remaining proportion is iron and other trace elements. The iron-chromium-nickel alloy has high tensile strength and high ductility, and thus is advantageous for improving the forging processability of the stainless steel alloy.

A secondary object of the present invention is to provide an iron-chromium-nickel alloy for a golf club head which can be hot forged at a temperature of 900 to 1000 ° C, and has a processing rate of 30 to 60%, and can be selected after forging. The heat treatment is carried out at a temperature of 780 to 930 ° C for 1 to 2 hours, so that the microstructure of the forging becomes a two-phase structure of (Mada's loose iron matrix + 5 to 15 wt% Worthite iron), thereby facilitating the surface of the golf iron head Nature, rust resistance and ductility.

Another object of the present invention is to provide an iron-chromium-nickel alloy of a golf club head, wherein the trace element contains 0.4 to 1.2 wt% of lanthanum and or 0.4 to 1.2 wt% of manganese, thereby preventing pore formation and promoting shrinkage by ruthenium, increase Adding molten steel fluidity; by manganese to eliminate the harmful effects of sulfur on the hot brittleness of the alloy, removing oxides in the alloy, and stabilizing the metallurgical structure, it helps to improve the casting properties and mechanical strength.

A further object of the present invention is to provide an iron-chromium-nickel alloy of a golf club head, wherein the trace element comprises 1.0 to 3.5 wt% of copper and/or 0.1 to 1.0 wt% of aluminum, and the alloy is resistant to atmospheric corrosion by copper. Performance, and can improve strength and toughness; aluminum is combined with oxygen in molten steel to form alumina, which acts as a strong deoxidizer and inhibits grain growth, thus contributing to corrosion resistance and oxidation resistance. , ductility, forging processability and toughness.

Another object of the present invention is to provide an iron-chromium-nickel alloy of a golf club head, wherein the trace element comprises 0.1 to 1.0 wt% (titanium + niobium + vanadium), and the alloy density is lowered by titanium and the corrosion resistance is increased;铌 Refinement of grains and reduction of alloy superheat sensitivity and temper brittleness, and resistance to atmospheric corrosion; vanadium is used as an oxygen scavenger in molten steel to refine microstructure grains, thus helping to reduce The center of gravity of the club head increases corrosion resistance, mechanical strength and toughness.

To achieve the above object, the present invention provides a golf club head iron chromium nickel alloy comprising 11 to 13 wt% of chromium, 4.5 to 5.5 wt% of nickel, 0.15 to 0.25 wt% of nitrogen, and 0.05 to 0.15 wt%. Carbon, the remaining proportion is iron and trace elements, the trace elements may be selected from the group consisting of: 0.4 to 1.2 wt% bismuth, 0.4 to 1.2 wt% manganese, 1.0 to 3.5 wt% copper, 0.1 to 1.0 wt. % aluminum, 0.1 to 1.0 wt% (titanium + lanthanum + vanadium) and combinations thereof. The iron-chromium-nickel alloy has a 180ksi or more Tensile strength, relief strength above 165ksi and elongation of more than 25%, it belongs to Ma Tian loose iron-Worthfield iron stainless steel, suitable for forging or casting golf iron head for improving the resistance of golf iron head Tensile strength, ductility, rust resistance, forging processability and casting properties.

In an embodiment of the invention, the iron-chromium-nickel alloy is applied to a forged golf iron head, which is hot forged at a temperature of 900 to 1000 ° C to make a golf iron head, and then selectively at 780 to Heat treatment at 930 ° C for 1 to 2 hours to further increase the elongation of the iron-chromium-nickel alloy of the golf iron head to more than 25%.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The invention discloses an iron-chromium-nickel alloy of a golf club head, which mainly comprises iron (Fe), chromium (Cr) and nickel (Ni), wherein nitrogen (N), carbon (C) and strontium can also be doped or added ( Trace elements such as Si), manganese (Mn), copper (Cu), aluminum (Al), titanium (Ti), niobium (Nb), and vanadium (V), and the iron-chromium-nickel alloy is basically a granulated iron-fertilizer Granular iron stainless steel. In one embodiment of the invention, the iron-chromium-nickel alloy comprises 11 to 13 wt% chromium, 4.5 to 5.5 wt% nickel, 0.20 to 0.40 wt% (nitrogen + carbon), and the balance is iron. In another embodiment of the present invention, the iron-chromium-nickel alloy comprises 11 to 13 wt% of chromium, 4.5 to 5.5 wt% of nickel, 0.15 to 0.25 wt% of nitrogen, and 0.05 to 0.15 wt% of carbon, and the remaining ratio is Based on iron and containing at least A trace element, wherein the trace element may be selected from the group consisting of: 0.4 to 1.2 wt% of ruthenium, 0.4 to 1.2 wt% of manganese, 1.0 to 3.5 wt% of copper, 0.1 to 1.0 wt% of aluminum, 0.1 Up to 1.0 wt% (titanium + lanthanum + vanadium) and combinations thereof.

Please refer to Figures 4, 5, 6 and 7 for a comparison of the composition ratio and mechanical properties of the examples and comparative examples of the iron-chromium-nickel alloy of the present invention, wherein the numbers 1 to 10 are the component categories of the present invention. Nos. 11 to 14 are comparative examples (the relevant data is the average of 10 sample pieces sampled). As can be seen from the figure, the alloy material of No. 1 consisting of iron -11.6 wt% chromium - 4.52 wt% nickel - 0.051 wt% carbon - 0.154 wt% nitrogen, after mechanical heat treatment at 1000 ° C for 1 hour, has mechanical properties The strength is 165.4 ksi, the tensile strength is 182.4 ksi, and the elongation is 26.1%. If the heat treatment time is extended to 16 hours, the mechanical properties will change to a relief strength of 165.2 ksi, a tensile strength of 180.6 ksi, an elongation of 35.2%, and a rod head subjected to a 5% NaCl salt spray test for 48 hours and a golf ball. The shelling test was conducted in 3000 rounds. Further, an alloy material of No. 10 composed of iron - 12.94 wt% chromium - 5.11 wt% nickel - 0.114 wt% carbon - 0.214 wt% nitrogen - 0.834 wt% 矽 - 0.862 wt% manganese, etc., is passed through 900 to 1000 ° C After the hot forging process, the surface roughness is changed from 1.7 μm to 2.7 μm, which satisfies the requirement of high quality forged surface under Ra of less than 3 μm; and the mechanical property of No. 10 alloy material after heat treatment at 1000 ° C for 1 hour is The drop strength is 92ksi, the tensile strength is 141.9ksi, the elongation is up to 49.1%, and the ball head is qualified by the 5% NaCl salt spray test for 48 hours and the golf ball hitting 3000 test. this In addition, after the solution of the golf iron head forging of the embodiment of No. 10 after 1000 ° C solution heat treatment, a fine dendritic structure (fine granulated iron + 8.2 wt% Worth iron) can be obtained. Similarly, the components of the alloy materials numbered 1 to 10 are within the scope of the invention, and after mechanical treatment, the mechanical properties have a strength of between 165 and 170 ksi, and the tensile strength is between 180 and 185 ksi, and the elongation is up to 25 to 35%, and the salt spray test for 48 hours and the golf ball attack test were all qualified.

The following is a description of the ratio range of various added alloying elements and their effects on the properties of the iron-chromium-nickel alloy of the present invention, as follows:

Chromium (Cr): When chromium is added to the iron-chromium-nickel alloy of the present invention, not only the resistance of the iron-chromium-nickel alloy to corrosion and oxidation but also the formation of stable and hard carbides can be increased to enhance the iron-chromium-nickel alloy. Hardening energy and high temperature strength. Basically, chromium contributes to the formation of a body-centered cubic (BCC) Wolster iron stable phase. In the iron-chromium-nickel alloy of the present invention, when the chromium content is less than 15% by weight, the iron-nickel alloy of the iron-chromium-nickel alloy is insufficient, and the mechanical strength thereof is lower than the predetermined mechanical strength of the present invention. When the chromium content is more than 18% by weight, the iron phase of the Vostian will be excessive, and the elongation will be lower than the predetermined elongation of the present invention. Therefore, in order to facilitate the control of the microstructure of the iron-chromium-nickel alloy in the production process (Mata's iron base + 5 to 15 wt% Worth iron) to demonstrate the performance of the optimized golf iron head, the iron chromium of the present invention The chromium content of the nickel alloy should be controlled between 11 and 13 wt%.

Nickel (Ni): When nickel is added to the iron-chromium-nickel alloy of the present invention, not only the resistance of the iron-chromium-nickel alloy to corrosion and oxidation but also the stability is stabilized. Iron-chromium-nickel alloy face-centered cubic (FCC). In the iron-chromium-nickel alloy of the present invention, when the nickel content is less than 4.5%, the iron-nickel alloy of the iron-chromium-nickel alloy is unstable, and the relative Worth iron phase is excessive, and the elongation is low. The predetermined elongation rate of the present invention. When the nickel content is more than 5.5% by weight, the iron-nickel alloy of the iron-chromium-nickel alloy is stabilized, and the opposite Worth iron phase is insufficient, so that the mechanical strength is lower than the predetermined mechanical strength of the present invention, and pores are easily formed. Therefore, in order to facilitate the control of the microstructure of the iron-chromium-nickel alloy in the production process (Mata's iron base + 5 to 15 wt% Worth iron) to demonstrate the performance of the optimized golf iron head, the iron chromium of the present invention The nickel content of the nickel alloy should be controlled between 4.5 and 5.5 wt%.

Carbon (C), Nitrogen (N): Carbon and nitrogen are essentially indispensable elements of general steel materials. In addition to the formation of carbides or nitrides, they are also elements of the stable phase of the granulated iron. With carbon, As the nitrogen content increases, the Worthite iron decreases and the Matian loose iron becomes more stable. However, in the iron-chromium-nickel alloy of the present invention, when the carbon and nitrogen contents are too high, the corrosion resistance of the iron-chromium-nickel alloy is disadvantageous and pitting corrosion is caused. Therefore, if the iron-chromium-nickel alloy of the present invention can control or add 0.15 to 0.25 wt% of nitrogen and 0.05 to 0.15 wt% of carbon, it will contribute to the improvement of corrosion resistance and the stabilization of the granulated iron phase.

Cerium (Si): When doping or adding antimony in the iron-chromium-nickel alloy of the present invention, it is advantageous to prevent pore formation, enhance shrinkage, and increase fluidity of molten steel. However, in the iron-chromium-nickel alloy of the present invention, when the niobium content is more than 1.2% by weight, the elongation is disadvantageous. Therefore, if the iron-chromium-nickel alloy of the present invention can be added with 0.4 to 1.2% by weight, it will contribute to the improvement of castability. Quality, in order to carry out the process of casting raw materials.

Manganese (Mn): Manganese usually coexists with iron. Since manganese is easily combined with sulfur, the harmful effects of sulfur on the hot brittleness of the iron-chromium-nickel alloy of the present invention can be eliminated. Furthermore, manganese can remove oxides from iron-chromium-nickel alloys. In addition, manganese can also stabilize the ram field iron phase of the FCC structure. Therefore, in the iron-chromium-nickel alloy of the present invention, if 0.4 to 1.2% by weight of manganese can be added, it will contribute to lowering the hot brittleness and improving the casting property.

Copper (Cu): When doping or adding copper in the iron-chromium-nickel alloy of the present invention, it is advantageous to make the iron-chromium-nickel alloy resistant to atmospheric corrosion and to improve strength and toughness. However, when the copper content is more than 3.5% by weight, the iron-chromium-nickel alloy is made brittle and the ductility is lowered. Therefore, if the iron-chromium-nickel alloy of the present invention can be added with 1.0 to 3.5% by weight of copper, it will contribute to improvement of corrosion resistance, mechanical strength and toughness.

Aluminum (Al): When aluminum is doped or added to the iron-chromium-nickel alloy of the present invention, aluminum can be combined with oxygen in the molten steel to form alumina, which acts as a strong deoxidizer and inhibits grain growth. . However, when the aluminum content is more than 1.0% by weight, the hot workability, weldability and machinability of the iron-chromium-nickel alloy are affected. Therefore, if the iron-chromium-nickel alloy of the present invention can be added with 0.1 to 1.0% by weight of aluminum, it will contribute to improvement of corrosion resistance, oxidation resistance, ductility and forging processability.

Titanium (Ti) + niobium (Nb) + vanadium (V): when doping or adding titanium, niobium and vanadium in the iron-chromium-nickel alloy of the present invention, the alloy density can be lowered by titanium and the corrosion resistance can be increased by铌 refine grains and reduce alloy superheat sensitivity and temper brittleness, and have resistance to atmospheric corrosion; and do by vanadium It is an oxygen scavenger in molten steel to refine the grain of the structure. However, when the (titanium + niobium + vanadium) content is more than 1.0 wt%, the ductility and toughness of the iron-chromium-nickel alloy will be affected. Therefore, if the iron-chromium-nickel alloy of the present invention can be added with 0.1 to 1.0% by weight (titanium + niobium + vanadium), it will help to lower the center of gravity of the club head and improve corrosion resistance, mechanical strength and toughness.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Fig. 1 is a comparison table of the characteristics of the golf iron head produced by the precision dewaxing casting method and the forging processing method.

Fig. 2 is a comparison table showing the mechanical properties of the alloy material used in the precision dewaxing casting method of the conventional golf iron head, the alloy material used in the forging processing method, and the iron-chromium-nickel alloy of the present invention.

Figure 3: Basic structural distribution of the conventional iron-chromium-nickel stainless steel alloy series and the iron-chromium-nickel alloy of the present invention (the well-lined mark).

Fig. 4 is a comparison table showing the composition ratio and mechanical properties of the examples of the iron-chromium-nickel alloy of the present invention and the comparative examples.

Fig. 5: Metallographic diagram of the casting of the numbered example 1 after heat treatment at 1000 ° C for 1 hour.

Figure 6: Metallographic diagram of the forged piece of Example No. 10 after solution heat treatment at 1000 °C.

Figure 7: Metallographic diagram of the casting of the example numbered 12.

Claims (9)

An iron-chromium-nickel alloy of a golf club head comprising 11% to 13% chromium, 4.5 to 5.5 wt% nickel, 0.15 to 0.25 wt% nitrogen and 0.05 to 0.15 wt% carbon, and the remaining proportion is mainly iron The iron-chromium-nickel alloy further comprises 0.1 to 1.0 wt% of aluminum; the iron-chromium-nickel alloy is hot forged at a temperature of 900 to 1000 ° C to produce a golf club head, and the golf club head has a tensile strength of 180 ksi or more. , the undulation strength above 165ksi and the elongation of 25% or more. The iron chrome-nickel alloy of the golf club head according to claim 1, wherein the golf club head is a golf iron head. The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy further comprises 0.4 to 1.2 wt% of bismuth. The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy further comprises 0.4 to 1.2 wt% of manganese. The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy further comprises 1.0 to 3.5 wt% of copper. The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy further comprises 0.1 to 1.0 wt% (titanium + niobium + vanadium). The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy is forged at a temperature of 900 to 1100 ° C after hot forging, and then heat-treated at 780 to 930 ° C to 1 2 hours to increase the elongation of the iron-chromium-nickel alloy to more than 30%. The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the iron-chromium-nickel alloy has a structure of (Mada's loose iron + 5~15wt% Vostian iron). The iron-chromium-nickel alloy of the golf club head according to claim 1, wherein the weight percentage of chromium is 12.21 wt% < Cr ≦ 13 wt%, and the weight percentage of nickel is 4.52 wt% ≦ Ni < 5 wt%.