JP2011058040A - Iron alloy suitable for composing iron golf club head and iron golf club head made thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture an iron golf club head that retains elongation and workability suitable for shape adjustment etc. and shows high tensile strength, and to produce an iron alloy used for formation of the same. <P>SOLUTION: The iron alloy suitable for composing the iron golf club head has a composition comprising, based on the total weight, 16.3-17.2 wt.% Cr, 5.8-6.5 wt.% Ni, 0.10-0.20 wt.% N, 0.01-0.12 wt.% C, 0.3-1.2 wt.% Si, 0.3-1.2 wt.% Mn and the balance being Fe and unavoidable impurities, has a dual-phase structure comprising a martensitic phase and 10-30% austenitic phase and has a tensile strength of ≥120 Ksi and an elongation of ≥35%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an iron-based alloy suitable for the construction of an iron club head and an iron club head made of the same.

  There are usually several types of golf clubs, such as wood clubs, iron clubs, pitching wedges, sound wedges and putters.

  Among them, the iron club is intended to make the ball reach the target accurately, and its feature is that the flying distance is short but the hitting ball is high compared to the wood club, and the ball is directed in the target direction. It is easy to hit.

  Current iron club heads are usually formed of titanium alloy, soft iron material, or stainless steel.

  As shown in FIG. 1 or FIG. 2, for example, an iron head made of low carbon steel (S25C) among those made of the above material has an elongation of 30% or more, but has a tensile strength of 120 Ksi. It is the following, and because it is very soft, there is a merit that it is possible to obtain a soft hitting feeling and easy adjustment of the angle such as the loft angle, but on the other hand, the head is easily deformed, rusted and surface treated (for example Nickel treatment or chromium treatment) is required.

  On the other hand, for example, an iron head made of 475 stainless steel (475SS) has a tensile strength of 290 Ksi, is too high, and has an elongation rate as small as about 6%. I can't get a sense.

  The present invention relates to an iron club head that does not require rust prevention treatment, has an elongation and workability suitable for hitting ball feeling and shape adjustment, and has an appropriate tensile strength that is difficult to be deformed during use, and the iron club It is an object of the present invention to provide an iron-based alloy formed with the manufacture of a head.

  In order to achieve the above object, based on the total weight, Cr: 16.3 to 17.2 wt%, Ni: 5.8 to 6.5 wt%, N: 0.10 to 0.20 wt%, C: 0.01 to 0.12% by weight, Si: 0.3 to 1.2% by weight, Mn: 0.3 to 1.2% by weight, balance: Fe of main component and inevitable impurities An iron club which has a component composition, has a multiphase structure composed of “martensite phase + 10-30% austenite phase”, has a tensile strength of 120 Ksi or more and an elongation of 35% or more. An iron-based alloy suitable for the construction of a head is provided.

  In addition, Cr: 16.3 to 17.2 wt%, Ni: 5.8 to 6.5 wt%, N: 0.10 to 0.20 wt%, C: 0 based on the total weight 0.01 to 0.12 wt%, Si: 0.3 to 1.2 wt%, Mn: 0.3 to 1.2 wt%, Cu: 2.8 to 3.2 wt%, Ti, Nb and V : 0.15 to 0.50% by weight, remainder: a component composition consisting of Fe as a main component and unavoidable impurities, and consisting of “martensite phase + 10-30% austenite phase” Also provided is an iron-based alloy suitable for the construction of an iron club head characterized by having a structure and a tensile strength of 120 Ksi or more and an elongation of 35% or more.

  The present invention also provides an iron club head whose material is the iron-based alloy.

  The present invention controls the iron club head and the iron club head by controlling each component, particularly the nitrogen content, to exhibit a multiphase structure consisting of “martensite phase + 10-30% austenite phase” in the microscopic structure. The iron base alloy formed together with the manufacture of the iron club head can be provided with rust prevention ability (surface treatment is not required), elongation rate, and tensile strength superior to those of the prior art.

It is a material type table of the conventional iron club head. It is a distribution map of the tensile strength and elongation rate of the conventional unclamp head and the unclamp club of the present invention. It is a microscopic structural diagram of 100 times of the first embodiment of the present invention. FIG. 4 is an electron micrograph of 45,000 times the martensite phase in FIG. 3. This figure shows dislocations in a layered martensite matrix. It is a restricted field diffraction pattern of the [111] direction of the martensitic phase of the 1st Embodiment of this invention which makes camera length 8.7 * 10 < ⁸ > nm. In this figure, the structure of martensite is a body-centered cubic lattice having a lattice constant (a) of 0.287 nm. FIG. 4 is an electron micrograph of 45,000 times the austenite phase in FIG. 3. This figure shows dislocations in a layered austenite matrix. FIG. 6 is a limited field diffraction diagram in the [001] direction of the austenite phase according to the first embodiment of the present invention, in which the camera length is 8.7 × 10 ⁸ nm. In this figure, the structure of austenite is a face-centered cubic lattice having a lattice constant (a) of 0.368 nm.

[First Embodiment]
The iron-based alloy suitable for the configuration of the iron club head according to the first embodiment of the present invention is Cr: 16.3 to 17.2% by weight, Ni: 5.8 to 6.5% by weight based on the total weight. %, N: 0.10 to 0.20 wt%, C: 0.01 to 0.10 wt%, Si: 0.3 to 0.8 wt%, Mn: 0.3 to 1.0 wt% And the balance: a component composition consisting of Fe as a main component and inevitable impurities, and a multiphase structure consisting of “martensite phase + 10-30% austenite phase”, and a tensile strength of 130-145 Ksi. The yield strength is 70 to 90 Ksi, and the elongation is 35% to 55%.

  The multiphase structure is formed by applying a solution treatment at a temperature of 950 to 1150 ° C. for 0.5 to 2 hours.

  Hereinafter, the configuration principle will be described first.

  The addition of Cr improves the corrosion resistance and oxidation resistance of the material, and exhibits a multiphase structure consisting of “martensite phase + 10-30% austenite phase”. Therefore, the Cr content is 16.3-17. It is preferable to control within the range of 2% by weight.

  The addition of Ni serves to control the microscopic structure of the alloy. When the Ni content is less than 5.8% by weight, the austenite phase is unstable and the elongation is 35% or less. When the content is more than 6.5% by weight, the austenite phase is stable. Since the tensile strength is insufficient and the mechanical strength of the golf club head made of the alloy is insufficient, it is necessary to control the content to an appropriate content. Moreover, in order to exhibit the multiphase structure which consists of "martensite phase + 10-30% austenite phase", it is preferable to control the content rate of Ni in the range of 5.8 to 6.5 weight%.

  N is advantageous not only for the formation of the austenite phase but also for the elongation of the alloy.

  If the N content is less than 0.10% by weight, the austenite phase is unstable, and the elongation is 35% or less. If the content is more than 0.20% by weight, an excessive amount is required in the alloy production process. Since the gas is generated, the alloy becomes brittle. Therefore, the N content is preferably controlled in the range of 0.10 to 0.20% by weight.

  C is present in the alloy as a carbide and is not only an essential constituent element for an iron-based alloy but also an element necessary for the martensite phase. However, an increase in the C content results in the formation of a large amount of carbides, which may adversely affect the corrosion resistance, weldability, and mechanical properties of the alloy material. It is preferable to control within the range of 01 to 0.12% by weight.

  Si prevents the formation of pores in the alloy, promotes the shrinking action, and increases the fluidity of the molten steel. If the content is 0.3 to 1.2% by weight, the casting of the alloy Is advantageous.

  Mn coexists with Fe and easily binds to S. Therefore, thermal embrittlement of the alloy by S can be prevented, and oxides in the alloy can be removed. Furthermore, since Mn can stabilize the martensite phase, controlling the content to 0.3 to 1.2% by weight is advantageous for producing an alloy and preventing thermal embrittlement.

[Second Embodiment]
The iron-base alloy suitable for the configuration of the iron club head according to the second embodiment of the present invention is based on the total weight of Cr: 16.3 to 17.2 wt%, Ni: 5.8 to 6.5 wt. %, N: 0.10 to 0.20% by weight, C: 0.01 to 0.12% by weight, Si: 0.3 to 1.2% by weight, Mn: 0.3 to 1.2% by weight, Cu: 2.8 to 3.2% by weight, Ti, Nb and V: 0.15 to 0.50% by weight, the balance: a component composition consisting of Fe as a main component and inevitable impurities, and In addition to exhibiting a multiphase structure composed of “martensite phase + 10-30% austenite phase”, the tensile strength is 120-160 Ksi, the yield strength is 60-100 Ksi, and the elongation is 35% -55%.

  The multiphase structure is formed by performing a solution treatment at a temperature of 950 to 1150 ° C. for 0.5 to 2 hours and then performing an aging treatment at 450 to 600 ° C.

  The reason for adding Cr, Ni, N, C, Si, and Mn is the same as that in the first embodiment, and therefore the addition of Cu, Ti, Nb, and V will be described below.

  Cu is for increasing the mechanical strength of the alloy golf club head. When the content is less than 2.8% by weight, the strength of the entire club club is insufficient, and the content is 3.2. When the amount is more than% by weight, it tends to rust and adversely affects the oxidation resistance of the alloy. Therefore, it is preferably in the range of 2.8 to 3.2% by weight.

  The addition of Ti, Nb, and V can make the alloy particles fine, and has the function of strengthening the alloy strength by aging treatment. If the content is 0.15 to 0.50% by weight, It is advantageous for casting.

〔Example〕
Examples of the present invention and comparative examples will be described below.

  The alloys (golf club heads) of the examples and comparative examples of the present invention can be manufactured by a conventional casting method.

  For example, a wax mold having the same shape as a golf club head is made of wax, the periphery is covered with cast sand, the wax mold is melted and discharged from an opening formed in a layer made of cast sand, and a sand mold with a cavity is formed. Next, each component as shown in Table 1 is melt-mixed and then mixed into a sand mold cavity while controlling so as to form a multiphase structure consisting of “martensite phase + 10-30% austenite phase”. After injecting and solidifying through heat treatment based on each Example and Comparative Example shown in Table 1, the sand mold is destroyed and the molded product is taken out. Finally, the iron club head is completed by polishing and finishing. To do. The tensile strength, yield strength, and elongation of the completed iron club head were measured and entered in Table 1. Examples 1 to 4 are iron-based alloys (golf club heads) according to the first embodiment of the present invention. Examples 5 to 12 are iron-based alloys (golf club heads) according to the second embodiment of the present invention. ). Comparative Examples 1 to 4 are iron-based alloys (golf club heads) outside the range of the components of the present invention.

  Comparing the data entered in Table 1, both the iron-based alloys of the first embodiment and the second embodiment have a tensile strength of 120 to 160 Ksi and an elongation of 35% to 55% (see FIG. 2). (See the tensile strength and elongation of the alloy of the present invention), in particular, by controlling the N content in the range of 0.10 to 0.20% by weight, it was far superior to Comparative Examples 1 to 4. Has a growth rate. Therefore, the golf club head that is the iron-based alloy of the first and second embodiments has an elongation suitable for hitting ball feeling and shape adjustment, and an appropriate tensile strength in use.

  In addition, in the microscopic structural diagram of Example 1 of the first embodiment of the present invention, the acicular martensite phase and the massive austenite phase (see the microscopic structural diagram in FIG. 3) are clearly visible. Further, when the alloy of Example 1 of the first embodiment of the present invention was examined in detail with an electron microscope, the martensite phase [see the electron micrograph of FIG. 4 (a) and the limited field diffraction diagram of FIG. 4 (b)]. In addition, the austenite phase (see the electron micrograph of FIG. 5A and the limited field diffraction diagram of FIG. 5B) can be clearly confirmed.

  The iron-based alloy of the first embodiment (Examples 1 to 4) and the iron-based alloy of the second embodiment (Examples 5 to 12) are both a salt spray test (48 hours) and a 3000 shot test. Have passed. Therefore, the golf club head of the present invention does not need to be rust-proofed and has sufficient tensile strength, so that it is difficult to deform.

  Incidentally, the salt spray test is a test for testing the corrosion resistance of materials, and is performed by spraying a solution containing 5% sodium chloride from a nozzle at 35 ° C. ± 3 ° C. The iron-base alloys of the first embodiment and the second embodiment passed this test because they were not corroded even when sprayed with 5% sodium chloride solution for 48 hours.

  Further, in the 3000 ball hitting test, even if the golf club head of the first embodiment and the second embodiment hit the ball 3000 times, the golf club head did not deform even in a slight amount. From the above, it is proved that the golf club head of the present invention has sufficient mechanical strength.

  As described above, the present invention, by controlling each component, particularly the nitrogen content, presents a multiphase structure consisting of “martensite phase + 10-30% austenite phase” in the microscopic structure, The iron club alloy and the iron-base alloy formed together with the manufacture of the iron club head can have rust prevention ability, elongation rate, and tensile strength superior to those of the prior art, so that the industrial utility value is high.

Claims (5)

Based on total weight,
Cr: 16.3 to 17.2% by weight,
Ni: 5.8 to 6.5% by weight,
N: 0.10 to 0.20% by weight,
C: 0.01 to 0.12% by weight,
Si: 0.3 to 1.2% by weight,
Mn: 0.3 to 1.2% by weight,
The remainder: a component composition consisting of Fe as a main component and inevitable impurities, and
An iron-based alloy suitable for the construction of an iron club head characterized by exhibiting a multiphase structure consisting of “martensite phase + 10-30% austenite phase”, having a tensile strength of 120 Ksi or more and an elongation of 35% or more.   2. The iron-based alloy according to claim 1, wherein the multiphase structure is formed by performing a solution treatment for 0.5 to 2 hours at a temperature of 950 to 1150 ° C. 3. Based on total weight,
Cr: 16.3 to 17.2% by weight,
Ni: 5.8 to 6.5% by weight,
N: 0.10 to 0.20% by weight,
C: 0.01 to 0.12% by weight,
Si: 0.3 to 1.2% by weight,
Mn: 0.3 to 1.2% by weight,
Cu: 2.8 to 3.2% by weight,
Ti, Nb and V: 0.15 to 0.50% by weight,
The remainder: a component composition consisting of the main components Fe and inevitable impurities, and
An iron-based alloy suitable for the construction of an iron club head characterized by exhibiting a multiphase structure consisting of “martensite phase + 10-30% austenite phase”, having a tensile strength of 120 Ksi or more and an elongation of 35% or more.   The multiphase structure is formed by performing an aging treatment at 450 to 600 ° C. after performing a solution treatment for 0.5 to 2 hours at a temperature of 950 to 1150 ° C. The iron-base alloy according to claim 3.   An iron club head made of the iron-based alloy according to any one of claims 1 to 4.