JPH03138336A - Spike for sports shoes - Google Patents

Abstract

PURPOSE:To offer the spike for sports shoes excellent in sediment wear resistance, light in weight and having high toughness by using a steel of which the atomizing powder of a high speed tool steel in which the relationship between the C content and the carbon equivalent is specified is mixed with TiN or the like and the mixture is compacted and sintered. CONSTITUTION:A high speed tool steel satisfying 0.1 <=C-carbon equivalent (Ceq) <=0.6 in the range of, by weight, 2.0 to 3.5% C and constituted of 3 to 10% Cr, 1 to 20% W, 1 to 11% Mo (where 18<=W+2Mo<=24 is regulated), 5.6 to 15% V, <=15% Co, <=2% Si, <=1% Mn and the balance Fe with impurities is subjected to atomizing. The atomizing powder, 88 to 98%, is uniformly mixed with total 2 to 12% of one or more kinds among the nitrides, carbides and carbon nitrides of Ti, Zr, V, Nb, Hf and Ta. By using a super hard high speed tool steel of which the above mixture is compacted and sintered, the spike is manufactured. Furthermore, Ceq=0.06Cr+0.033W+0.063Mo+0.2V is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to spikes that are attached to athletic shoes such as golf shafts and baseball shoes.

[Conventional technology]

Spikes attached to athletic shoes have traditionally been made of mild steel, but they wear out quickly due to friction with earth and sand, rendering the spikes useless and requiring frequent replacement. As a countermeasure to this problem, in recent years, cemented carbide or ceramics have been used for spikes for athletic shoes.

[Problem to be solved by the invention]

When spikes for athletic shoes are made of cemented carbide or ceramics, the wear resistance against dirt and sand is much better than that of mild steel, but the specific gravity is 7% higher than that of mild steel.
．． Since it is larger at 13.0 compared to 8, the weight of the athletic shoes becomes heavier, and the speed of exercise, such as walking, decreases.
There were problems such as feeling tired in the legs.

In the case of ceramics, the abrasion resistance against dirt and sand is comparable to that of cemented carbide, and since the specific gravity is as low as 4.0, athletic shoes can be made lighter and have great effects on exercise. However, due to the brittleness peculiar to ceramics, there was a problem in that it would chip when it collided with stones, concrete, etc., which would impair its role as a spy door.

In view of the above-mentioned problems, an object of the present invention is to provide spikes for athletic shoes that are lightweight and have high toughness and excellent earth and sand abrasion resistance.

[Means to solve the problem]

In the present invention, the equilibrium carbon content (Ceq) is a weight ratio, and Ceq=
0.06 Cr+0.033W+0.063Mo+0.
When 2V, C: 0 in the range of 2.0 to 3.5%
．． 1≦C-Ceq≦0.6, and further Cr:
3-10%, W: 1-20%, Mail-11% (however, 18≦W12Mo≦24), V: 5.6-15%, C
, o: 15% or less, Si: 2% or less, M n : 1%
Hereinafter, the atomized powder of high speed tool steel consisting of the balance Fe and impurities is 88-98%, Tj, Zr, V, Nb
, Hf, Ta nitride, carbide, carbonitride, or two or more types in total of 2 to 12% in total are uniformly mixed and then formed and sintered to use a super hard high speed tool steel. This is a distinctive feature of spikes for athletic shoes.

[Effect]

Next, the effect of each additive element in the present invention and the reason for limiting the range of addition thereof will be described.

Among the compositions of the material of the spikes for athletic shoes of the present invention, the content of C is the most important component.

C combines with Cr, W, Mo, and V contained at the same time to form M
, C, MC, etc., which imparts wear resistance, increases the hardness of the martensite base through quench hardening heat treatment, and further increases the amount of secondary hardening by tempering. It is theoretically known that the equilibrium carbon amount Ceq at which the carbide-forming elements Cr, W, Mo, and V and C combine in just the right amount to form a carbide is expressed by the following formula.

Ceq=0.06(%Cr) +0.033(%W)+
0.063 (% Mo) 10.2 (%■) In conventional high-speed tool steel, the C content and equilibrium carbon 1
The difference in ceq, C-Ceq, is adjusted to be negative (for example, JIS 5KH59 has a difference of -0.
3, -0.05 for A151M42).

In the present invention, even if the amount of W, Mo, V or dispersed particles such as TiN is relatively small, superhardness of HRC72 or higher can be obtained, and in order to obtain highly practical spikes, many materials are used for spikes. As a result of experiments and studies on high-speed tool steel, Ceq = 0.06Cr + 0.033W +0
．． When 063Mo+0.2V, 18≦W12 M
It was newly discovered that C-Ceq should not be made negative in the range of O≦24, but should be contained so as to satisfy 0.1≦C-Ceq≦0.6.

When C-Ceq is less than 0.1, a large amount of W
, Mo, V, and TiN, superhardness of HRC 72 or higher cannot be obtained. On the other hand, if C-Ceq exceeds 0.6, stable retained austenite increases significantly during quench hardening heat treatment, and the decomposition temperature of retained austenite shifts to a higher temperature side, so even if secondary hardening is performed by tempering, , it becomes impossible to obtain a superhardness of HRC72 or higher. That is, in the range of 18≦W12Mo≦24, 0.1≦C−C
The purpose of the present application can be achieved only under the condition of eq≦0.6.

As mentioned above, C should be appropriately changed depending on the amounts of Cr, w, Mo, and v contained at the same time.

At least 2.0% is required to satisfy 0.1≦C-Ceq≦0.6 within the content range of Cr, W, Mo, and V of the present invention, which will be described later.

On the other hand, even if the above conditions are met, the C content remains at 3.5%.
If the C content exceeds 2, the decrease in toughness will be significant.
．． Within the range of 0 to 3.5%, 0.1≦C-Ceq≦0
．． Limited to 6.

Cr has the effect of increasing quench hardenability, but if it is less than 3%, this effect is small; on the other hand, if it exceeds 10%, the amount of retained austenite increases and the quenching and tempering hardness decreases, so the Cr content should be 3 to 3%. It was limited to 10%.

In particular, in order to obtain a superhardness of HRC 72 or higher even when heat treated in a quenching furnace with a slow cooling rate such as vacuum quenching, the Cr content is desirably more than 6% and 10% or less.

As mentioned above, W and Mo combine with C to form M and C type carbides, which have the effect of increasing the wear resistance against earth and sand such as the spikes of athletic shoes, and solid solution in the matrix during quench hardening heat treatment. This is precipitated as fine carbides by tempering heat treatment and has the effect of increasing the degree of secondary hardening. :1~20%, Ma
It is necessary to contain 18% or more of W+2Mo in the range of il to 11%. However, if the amount of W+2Mo exceeds 24%, the material not only becomes expensive but also has a lower toughness.

The content of Mo was limited to 18 to 24% in W+2Mo amount.

Note that, in the present invention, W and Mo in equal amounts in atomic percent have approximately equivalent effects.

(2) also combines with C, like W and Mo, to form an MC type carbide. The hardness of this MC type carbide is 1 (v2500 ~
3000, and the hardness of M and C type carbides is HV1500~
It has significantly higher hardness than 1800. For this reason, in parts such as spikes where wear resistance is particularly important, ■
Using a high-speed tool steel with a high content increases the service life.

■ Even if the content is increased more than necessary, the grindability will deteriorate.
(2) The content was limited to 5.6 to 15% because it lowers toughness and, if too small, the effect of improving wear resistance is insufficient.

Go is dissolved in the matrix and has the effect of increasing the tempering hardness. However, if Go is contained in a large amount, the toughness will be significantly reduced, so the content of Go is limited to 15% or less.

Si is contained at 2% or less for the purpose of deoxidizing the steel used in the present invention, but especially in the range of 0.8 to 2% Si, in addition to the deoxidizing effect, it also has the effect of increasing the hardness of the matrix and improving the corrosion resistance. effect, and furthermore, an effect of improving the atomization workability. If it exceeds 2%, the toughness will be significantly reduced.

Mn also has a deoxidizing effect and also has the effect of increasing hardenability, so it is contained in an amount of 1% or less. In particular, when the above-mentioned Si content is high, Mn can stabilize the ferrite and alleviate the adverse effects of SL, which increases the A1 transformation point.
It is preferable to contain Mn in an amount of 0.25 to 1.0%.

Nitride, carbide of Ti, Zr, V, Nb, Hf, Ta,
Dispersing carbonitride has the effect of increasing hardness.

On the other hand, as in the present invention, the C content is equal to the equilibrium carbon amount (Ceq)
It is conventional wisdom that if the value is higher than 0.1 to 0.6, the austenite crystal grains will become coarse during the quench hardening process, the martensite structure will become rough, and the toughness will be extremely reduced.

However, in the present invention, TI, Zr, V, Nb, Hf
.

This drawback can be overcome by uniformly dispersing one or more Ta nitrides, carbides, and carbonitrides in a total amount of 2 to 12%. We discovered that even if quench hardening treatment is performed in the austenitizing temperature range, a significantly finer structure can be obtained.

That is, by dispersing one or more of the above nitrides, carbides, and carbonitrides, the C content can be reduced to Ceq
This successfully compensates for the drawbacks caused by setting it higher than m, and achieves the object of the present invention.

However, with 2% undropped, the above effect is small, while with 12%
Exceeding this value not only saturates the effect, but also significantly reduces the grindability when finishing into spikes and the toughness during use, so the amount of dispersion of the nitrides, carbides, and carbonitrides should be 2 to 12% in total. limited to.

A method for uniformly dispersing nitrides, carbides, and carbonitrides in a matrix is to produce high-speed tool steel powder with the above chemical composition by atomizing water, gas, oil, etc. The most suitable method is to mix the powder, carbide, or carbonitride powder, then mold and sinter it.

When mixing, carbon powder such as graphite powder or black carbon may be added and mixed at the same time for the purpose of adjusting the final carbon content after sintering and improving sinterability. Furthermore, Cr.

One or two of Ni, Mo, W, Cu, Go, Fe powder
Simultaneously mixing 5% or less of these species in total has the effect of improving sinterability.

〔Example〕

Next, the present invention will be explained in more detail based on one embodiment. In order to make spikes to be attached to golf shoes,
First, the spike materials shown in Table 1 were prepared. This material is manufactured by sintering atomized powder.

Spikes to be attached to golf shoes were made from this material, and the specific gravity, Charpy value (10R notch), and hardness (Samples A, B, and E were quenched and tempered) were measured in order to understand the characteristics of the material. The results are shown in Table 2.
According to the table, cemented carbide has the highest specific gravity at 13.0, and ceramic has the lowest specific gravity at 4.0.

Superhard high-speed tool steel and mild steel exhibit the same level of specific gravity.

The Charpy value is the lowest for cemented carbide (0.4 kg-m/-
However, ultra-hard high-speed tool steel is 0.6 kJ-m.
/- is shown. Further hardness measurements showed that ultrahard high-speed tool steel is much harder than mild steel, although it is not as hard as cemented carbide or ceramics.

Next, the manufactured spikes were attached to golf shoes and a lifespan test was conducted. The test consisted of 18 holes per day.
The presence or absence of chips and bends was checked every day, and the amount of wear was measured.

The results are also shown in Table 2.

As a result of life tests, spikes made of cemented carbide and ceramics chipped or broke early, making them unusable.

The soft steel tool wore 2.1 mm in 20 days, but the carbide high-speed tool R according to the present invention wore 0.4 mm in 60 days, which means it has a lifespan approximately 15 to 20 times longer than that of the mild steel tool. I found that it was improving.

〔Effect of the invention〕

According to the present invention, the wear resistance of the spikes attached to athletic shoes, which was insufficient in the past, has been significantly improved, allowing them to be used for a long time, eliminating the need to frequently replace the spikes, and improving the reliability of athletic shoes. can be achieved.

Claims (1)

[Claims] 1 Equilibrium carbon content (C_e_q) is the weight ratio, C_e_q
=0.06Cr+0.033W+0.063Mo+0.
When 2V, C: 0.0 to 3.5%.
1≦C−C_e_q≦0.6, and further Cr:3
~10%, W: 1-20%, Mo: 1-11% (however, 18≦W+2Mo≦24), V: 5.6-15%, Co
: 15% or less, Si: 2% or less, Mn: 1% or less, the balance is 88 to 98% of the atomized powder of high speed tool steel consisting of Fe and impurities, Ti, Zr, V, Nb, Hf, T.
It is characterized by using a super hard high-speed tool steel obtained by uniformly mixing 2 to 12% of one or more of nitrides, carbides, and carbonitrides in a total of 2 to 12% and then forming and sintering it. Spikes for athletic shoes.