JPH11335791A - High hardness martensitic stainless steel for high frequency hardening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate high frequency hardening and to obtain a high hardness, in an alloy steel containing a specified weight % C, by making the number of carbide grains, which has a specified major diameter, existing within an observation visual field of a specified area of a cross-sectional high frequency hardened part of the steel a specified number. SOLUTION: In the steel, in which a chemical composition is, by weight, 0.4-1.20% C, preferably 0.50-0.75%, more preferably 0.60-0.70%, a number of the carbide grains having a major diameter of >=10 μm, which exist within an observation visual field of an arbitrary 1 mm<2> of a cross-sectional high frequency hardened part of the steel, are <=60 pieces, and further, an area ratio of the carbide grains of <=5 μm major diameter to a total area of the remaining carbide grains of <=10 μm major diameter exceeds 70%. Cr of 9.00-20.00 wt.%, preferably 11.00-13.50 wt.% is added for forming an inactive film on a steel surface and improving corrosion resistance. Si of 0.01-1.50 mass %, preferably 0.31-1.00 mass % is added for a deoxidizer for the steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-hardness martensitic stainless steel which can be easily subjected to induction hardening and is used for machine parts and machine elements requiring high hardness and corrosion resistance.

[0002]

2. Description of the Related Art Conventionally, martensitic stainless steel SUS440C of JIS steel is mainly used for mechanical parts and the like in an environment where high hardness and corrosion resistance are required. In order to improve abrasion resistance, fatigue resistance, etc., this steel has obtained high hardness by a combination of quenching and tempering by heating in a furnace and, in some cases, sub-zero treatment.

On the other hand, in recent years, since it is desired to perform quenching, which is a hardening treatment, on the entire length of a long part, or a part thereof, or a part of a deformed part, which is difficult to be performed by furnace heating, it is desired to perform induction hardening. Needs were increasing.

With conventional SUS440C grade stainless steel, if quenching and tempering by ordinary furnace heating, hardness equivalent to, for example, SUJ2 which is a high carbon chromium steel having a small Cr content can be obtained. Therefore, while maintaining wear resistance, it also possessed excellent corrosion resistance. However, applying the induction hardening has the following problems.

The feature of induction hardening is that the heating time is as short as several seconds to several tens of seconds, so that even a long part or a deformed part can be partially cured. on the other hand,
SUS440C is characterized in that there are many large eutectic carbides that precipitate during solidification. When induction hardening is performed on this SUS440C, there is no time to sufficiently dissolve the carbide in the matrix at a normal quenching temperature of about 1100 ° C. because there are many large eutectic carbides, which is equivalent to quenching by normal furnace heating. There was a problem that hardness could not be obtained.

In order to solve the above problem, if the quenching temperature is raised and the carbide is to be dissolved into the matrix in a short time, it is necessary to heat to a temperature near the liquidus line and quench. In this case, not only is the sub-zero treatment indispensable because the amount of retained austenite increases and the hardness decreases, for example, in the case of a processed material having a square shape, the corner tip is overheated and a part thereof is melted. Problems are more likely to occur. In other words, the induction hardening process is industrially expensive, and its control becomes very difficult. For the reasons described above, induction hardening into SUS440C steel has been extremely difficult.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the conventional high-hardness stainless steel, and even if spheroidizing annealing is performed before induction hardening, The purpose of the present invention is to achieve both the required quench hardness and the required quenching hardness.

[0008]

In order to achieve the above object, a high-hardness stainless steel for induction hardening according to the present invention comprises: (1) an alloy steel having a chemical composition of 0.4% to 1.20% by weight, A high-hardness martensitic stainless steel for induction hardening, comprising 60 or less carbides having a major axis of 10 μm or more in an arbitrary 1 mm ² observation field of view in a portion corresponding to induction hardening of a steel cross section. (2) High hardness for induction quenching, characterized in that the long diameter of the carbide is 10 μm or less in the portion corresponding to the induction quenching of the steel cross-section, which is an alloy steel having a chemical composition of weight% and containing C: 0.40 to 1.20%. Martensitic stainless steel

(3) Chemical composition in weight%, C: 0.40-1.
In an alloy steel containing 20%, there are 60 or less carbides with a major axis of 10 μm or more present in an arbitrary 1 mm ² observation field of view in a portion corresponding to induction hardening of the steel cross section, and the remaining major axis of 10 μm or less The major diameter is 5 for the total cross-sectional area of the carbide.
A high-hardness martensitic stainless steel for induction hardening, characterized in that the area ratio of carbides of μm or less exceeds 70%. (4) An alloy steel having a chemical composition of% by weight and containing C: 0.40 to 1.20%, wherein the major axis of the carbide in the portion corresponding to induction hardening of the steel cross section is 10 μm or less, and the remaining major axis is 10 μm.
A high-hardness martensitic stainless steel for induction hardening, wherein the area ratio of carbides having a major axis of 5 μm or less to the total cross-sectional area of carbides of m or less is more than 70%. (5) In (1) to (4), the C content is 0.50 to 0.5% by weight.
High-hardness martensitic stainless steel for induction hardening characterized by being an alloy steel substituted with 0.75%. (6) The high-hardness martensitic stainless steel for induction hardening according to any one of (1) to (4), wherein the high-hardness martensitic stainless steel is composed of an alloy steel having a chemical composition of, by weight%, Cr: 9.0 to 20.0%.

(7) The chemical composition is expressed by weight%, and Cr: 9.0 to
The high-hardness martensitic stainless steel for induction hardening according to (5), comprising an alloy steel containing 20.0%. (8) Chemical composition in weight%, Si: 0.01-1.50%, M
n: 0.03 to 2.00%, with the balance being Fe and unavoidable impurities, the high-hardness martensitic stainless steel for induction hardening according to (6) or (7). (9) Chemical composition by weight%, Si: 0.31-1.00%, M
n: High hardness martensitic stainless steel for induction hardening according to (6) or (7), characterized in that it contains 0.31 to 1.00% and the balance consists of Fe and inevitable impurities.

(10) A high-hardness martensitic stainless steel for induction hardening according to (6) to (9), wherein the Cr content is replaced by 11.00 to 13.50% by weight. (11) Mo: 0.05 to 2.00% by a chemical composition expressed in% by weight.
, W: 0.01-1.00%, Co: 0.01-1.00%, V: 0.01
0.50%, Nb: 0.01 to 0.50%, Ti: 0.0030 to 0.1000
%, B: 0.0005 to 0.0100%, Al: 0.030 to 0.100%,
N: one or more of 0.0200 to 0.1500%, and the balance consists of Fe and unavoidable impurities, and the balance consists of high-hardness martensite for induction hardening as described in (6) to (10). Series stainless steel.

(12) A chemical composition represented by weight%, wherein O: 0.
(6) to (1) wherein one or more of S: 0.010% or less and P: 0.015% or less are contained, and the balance is composed of Fe and unavoidable impurities.
High hardness martensitic stainless steel for induction hardening according to 0). (13) Mo: 0.05 to 2.00% by chemical composition expressed by weight%
, W: 0.01-1.00%, Co: 0.01-1.00%, V: 0.01
0.50%, Nb: 0.01 to 0.50%, Ti: 0.0030 to 0.1000
%, B: 0.0005 to 0.0100%, Al: 0.030 to 0.100%,
N: one or more of 0.0200 to 0.1500%, and O: 0.0030% or less, S: 0.010%, P: 0.01
High hardness martensitic stainless steel for induction hardening according to any one of (6) to (10), wherein one or more of 5% or less are contained, and the balance consists of Fe and unavoidable impurities. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The high-hardness stainless steel for induction hardening of the present invention can improve the induction hardenability and obtain high hardness mainly by limiting the size and number of eutectic carbides. This is the result of repeated experiments. Hereinafter, the reasons for limiting the claims in the present invention will be described.

[0014] Carbide particle size: 60 or less carbides having a major axis of 10 µm or more in 1 mm ² . One of the great features of induction hardening
First, it is hardened by heating for a short time. At this time, in order to obtain high hardness, it is necessary to form a solid solution of the carbide in the matrix. However, if the carbide is large, the solid does not form a solid solution in a short time, so that high hardness cannot be obtained. Further, when such carbides are large, the number of fine carbides decreases, and even if the fine carbides form a solid solution, sufficient hardness cannot be obtained.
Therefore, the number of carbides having a particle size of 10 μm or more in 1 mm ² is 6
Must be 0 or less. More preferably, if all the carbides are 10 μm or less, higher hardness can be obtained.

The area ratio of carbide having a major axis of 5 μm or less occupies more than 70% of the total cross-sectional area of the carbide having a major axis of 10 μm or less in an area ratio of 1 mm ² . As mentioned above,
It is very difficult for carbides of m or more to form a solid solution in a matrix by short-time heating with high frequency. For the same reason, the fineness is preferable even if it is 10 μm or less. In order to obtain particularly high hardness, the area ratio of carbides of 5 μm or less occupies more than 70% of the total carbide area. ,
Higher hardness can be easily obtained.

C: 0.40 to 1.20% C is an element necessary for obtaining sufficient hardness by induction hardening. Therefore, irrespective of the amount and size of the carbide, addition of a certain amount or more is necessary to obtain sufficient hardness, which is at least 0.40% or more. However, if added excessively, the eutectic carbides are likely to be coarsened, impeding solid solution during induction hardening, and further impairing the cold workability, in particular, so the upper limit was made 1.20%. Effectively, the content is preferably 0.50 to 0.75%, and more preferably 0.60 to 0.70%.

Cr: 9.00 to 20.00% Cr is an essential element for stainless steel because it forms a passivation film on the steel surface and improves corrosion resistance. For that purpose, the addition of 9.00% or more is necessary.However, an excessive addition has the effect of improving corrosion resistance, but on the other hand, it precipitates a large number of giant eutectic carbides and only hinders the increase in hardness in induction hardening. In addition, the upper limit was set to 20.00% because the cold workability and the like also deteriorated. Also, preferably 11.00
It is about 13.50%.

Si: 0.01-1.50% Since Si is added as a deoxidizing material for steel, the lower limit is made 0.01%, and it may be further added to improve the tempering softening resistance. However, an excessive addition impairs the cold workability, so the upper limit is set to 1.50%. Preferably, 0.
It is 31 to 1.00%, more preferably 0.31 to 0.70%.

Mn: 0.03 to 2.00% Mn is an element added to promote deoxidation or desulfurization. The lower limit is set to 0.03%. In some cases, Mn is added to impart hardenability. Then, the upper limit is set to 1.50% because the cold workability and the hot workability are impaired. Preferably, 0.
It is 31 to 1.00%, and more preferably 0.51 to 0.80%.

Mo: 0.05 to 2.00% Mo is known as an element for improving corrosion resistance. For this purpose, Mo may be added in an amount of 0.05% or more as necessary. Addition promotes the coarsening of carbides, thereby inhibiting solid solution of carbides during induction quenching and further increasing the material cost. Therefore, the upper limit was set to 2.00%. Preferably, 0.05
To 1.00%, and more preferably 0.10 to 0.50%.

W: 0.01% to 1.00% W forms a strong carbide, and may be added in an amount of 0.01% or more as necessary to impart wear resistance. Like Mo, the addition promotes coarsening of carbides and further increases the material cost, so the upper limit was made 1.00%.

Co: 0.01 to 1.00% Co forms a strong carbide similarly to W. Therefore, 0.01% or more may be added as necessary to impart abrasion resistance. High, excessive addition is Mo, W
Similarly to the above, the upper limit is set to 1.00% to promote coarsening of the carbide and further increase the material cost.

V: 0.01 to 0.50% V is an element which forms fine carbides or carbonitrides and is effective in preventing the crystal grains from being coarsened. Further, they serve as nuclei for carbide precipitation and contribute to fine dispersion of carbides. Can be added as needed. For its effect, at least 0.01% or more is necessary, but when added in excess, the effect is saturated, further promoting the accumulation of carbides at the grain boundaries, coarsening the carbides,
In addition, the material cost also increases, so the upper limit is 0.
50%.

Nb: 0.01 to 0.50% Nb is an element which forms a compound with C and N and is thus effective in preventing the crystal grains from coarsening, as in V. Further, they serve as nuclei for carbide precipitation, Can be added as necessary to contribute to the fine dispersion of.
For its effect, at least 0.01% or more is necessary, but if added in excess, the effect is saturated, further promoting the accumulation of carbides at the crystal grain boundaries, and coarsening the carbides, Further, the material cost is also increased, so the upper limit is set to 0.50%.

Ti: 0.0030 to 0.1000% Ti is an element forming nitride or carbonitride,
It can be a precipitation nucleus of carbide at the time of solidification, contributes to fine dispersion of carbide, and further suppresses carbonitride formation of B when B is added, so that the amount of dissolved B can be secured. It can be added as needed. But,
If added in excess, coarse nitrides are formed as non-metallic inclusions, which degrade corrosion resistance.
And

B: 0.0005 to 0.0100% B can be added as necessary to improve hardenability. For its effect, a content of 0.0005% or more is required. However, excessive addition saturates the effect, so the upper limit was made 0.0100%. When adding B, Ti
Is more effective at the same time.

Al: 0.030 to 0.100% Since Al is added as a steel deoxidizer, the lower limit is 0.030%.
Since nitrides are formed and have an effect of preventing crystal grain coarsening, they can be further added as necessary. However, if added excessively, the oxide-based inclusions tend to be coarsened, and the cold workability is deteriorated, so the upper limit was made 0.100%.

N: 0.0200 to 0.1500% N is present as an impurity element in stainless steel in a relatively large amount especially in stainless steel. N is V, Nb, Ti or A
and an element that forms a compound with these elements. These elements are finely precipitated and thus have an effect of preventing crystal grain coarsening.
Is added as necessary to provide tempering softening resistance.
0200% or more can be added. However, when added in excess, not only does the effect become saturated, but also because it becomes easy for cavities to be formed in the steel ingot due to supersaturated N during solidification,
The upper limit was set to 0.1500%.

O: 0.0030% or less O is an element forming nonmetallic inclusions, and the upper limit is 0.0030%.
If it is contained in excess of, the inclusions will increase significantly and become a starting point of corrosion, and in applications requiring fatigue resistance, it will be a starting point of damage.

S: 0.010% or less S forms a nonmetallic inclusion by forming a compound with Mn. While this compound improves machinability, it becomes the starting point of corrosion, and in applications where fatigue resistance is required, it becomes the starting point of damage.
Regulated to 010%.

P: 0.015% or less It is known that P is an element that segregates at grain boundaries and impairs impact resistance. Therefore, the upper limit was restricted to 0.015% as necessary.

Although Ni improves hardenability and corrosion resistance, it is an expensive element and deteriorates cold workability. Further, Ni has the effect of lowering the austenitizing temperature during heating, but it is not necessary in the present invention focusing on the amount of carbides, and it is desirable that the content be less than 0.30% by weight%.

Cu is known to improve the corrosion resistance in a non-oxidizing atmosphere.
May be added in the range of 0.10% to 1.00%, but excessive addition significantly impairs hot workability.

[0034]

EXAMPLES Table 1 shows the chemical components of the steel materials A to O of the present invention used in the experiment.

[0035]

[Table 1] Table 2 shows the chemical components of the comparative steels P to V.

[0036]

[Table 2]

These test materials were melted in an experimental melting furnace, and the steels A to N of the present invention and the comparative steels P to U had an inner diameter of about 150 m.
m ingot. Inventive steel O was cast into an ingot having an inner diameter of φ40 mm in order to increase the solidification rate during casting. Comparative steel V was solidified in about 24 hours by slow cooling in a melting crucible without ingot casting to slow down the solidification rate. The steel ingot obtained in this way is forged to about φ28 mm, and after spheroidizing annealing,
It was cut to 26 mm and subjected to microstructure observation and induction hardening test.

The microstructure observation before induction hardening was performed using an optical microscope in a range of 0 to 0.5 mm from the surface.
Induction quenching 100 ° C / sec up to surface temperature 1100 ° C,
And at a heating rate of 200 ° C./sec, and then immediately water-cooled. After quenching, tempering was performed in an electric furnace at 160 ° C. for 90 minutes, and the hardness of the quenched surface layer was measured. Hardness was measured by a Vickers hardness tester at a position 0.2 mm below the quenched surface of the test piece cross section.

One of the major features of induction quenching is short-time heating. In the case of general structural steel, most are heated to a quenching temperature (about 850 to 1000 ° C.) in a few seconds. on the other hand,
Since martensitic stainless steel, which has a large amount of carbide in the microstructure before induction hardening, needs to form a solid solution of the carbide, the heating time must be extended and the heating temperature must be increased. Considering the properties, it is hard to say that induction hardening is easy. Therefore, in order to facilitate this, at a heating rate of at least 100 ° C./sec
The required hardness must be obtained at a quenching temperature of 0 ° C. The required hardness depends on the use of the part, but is set to Hv650 or more.

Table 3 shows the results of measurement of the amount of carbide of each test steel before induction hardening and the hardness of the induction hardened surface layer at a heating rate of 100 ° C./sec and 200 ° C./sec.

[0041]

[Table 3] Since the steels A to O of the present invention satisfy 60 or less carbides having a major axis of 10 μm or more present in an arbitrary observation field of 1 mm ² , all of the steels of the induction hardened surface layer at least at a heating rate of 100 ° C./sec. The hardness is Hv650 or more.

Further, the steels A, B, D, and D of the present invention in which 0 carbides having a major axis of 10 μm or more existing in an arbitrary 1 mm ² observation visual field plane are 0 and all carbides are 10 μm or less in a major axis.
E, G, and J steels show a small decrease in quenching hardness when comparing the quenching hardness at a heating rate of 100 ° C./sec with the quenching hardness at a stricter heating rate of 200 ° C./sec. It has better induction hardening easiness than those not satisfying the regulations. Further, in the steels M and O of the present invention, the proportion of carbides having a major axis of 5 μm or less in the total carbide area is less than 70%, and it is difficult to obtain high hardness by quenching at a high temperature rising rate of 200 ° C./sec. When the proportion of carbide having a major axis of 5 μm or less is 70% or more, the easiness of induction hardening is further increased.

Also, there are 60 or less carbides having a major axis of 10 μm or more present in the arbitrary 1 mm ² observation field plane, and the total cross-sectional area of the carbides having a major axis of 10 μm or less is 5 μm or less. The area ratio occupied by carbide is 7
The steels of the present invention exceeding 0% show a small decrease in quenching hardness when comparing the quenching hardness at a heating rate of 100 ° C./sec with the quenching hardness at a stricter heating rate of 200 ° C./sec. However, it has better induction hardening easiness than those not satisfying this rule.

On the other hand, although the comparative steel P has a target microstructure before induction hardening, a high hardness cannot be obtained because the C content is too low, and the comparative steels Q to T have an arbitrary 1 mm ² observation field plane. Since there are more than 60 carbides having a major axis of 10 μm or more, a hardness exceeding the target Hv 650 is not obtained at a heating rate of 100 ° C./sec.

The steel O of the present invention and the comparative steel U have almost the same chemical composition, and correspond to JIS-SUS440C steel. In the production process of these two steels, the number of carbides having a major axis of 10 μm or more present in an arbitrary 1 mm ² observation field of view in the portion corresponding to induction hardening of the steel cross section is reduced to 60 or less due to a change in solidification rate, for example. This shows that by adjusting the amount of carbide, high hardness can be obtained by induction hardening, which is usually difficult.

That is, 17Cr-based JIS-SUS4
At a normal solidification rate, the number of carbides of 10 μm or more exceeds 74 and 60 at a normal solidification rate of 40C equivalent steel. Even at a heating rate of 100 ° C./sec, Hv610 and the hardened hardness are not sufficient. As in the case of the steel O of the present invention, the solidification rate of which was increased, the amount of carbide having a major axis of 10 μm or more and present in an arbitrary 1 mm ² observation visual field plane was adjusted to 58 (60 or less) in an observation field plane of 1 mm ² , thereby obtaining Hv677. Hardness was obtained.

This indicates that the steel J of the present invention and the comparative steel V
You can also see from the comparison. That is, at the solidification rate applied to the steel J of the present invention in the present example, the major axis of the carbide is 10 μm or less, and the area occupied by the carbide with the major axis of 5 μm or less with respect to the total cross-sectional area of the remaining carbide with the major axis of 10 μm or less. Rate is,
When quenching at a heating rate of 100 ° C./sec exceeds 70%, the quench hardness is excellent as Hv742, but in comparative steel V, which is almost the same component, the solidification rate and the like are remarkably slow in the production process. The microstructure before induction hardening has a major axis of 10 μm existing in an arbitrary 1 mm ² observation field plane.
Since the number of carbides of m or more was increased to more than 60 and 62, it was not possible to easily obtain high hardness of Hv647 in quenching at a heating rate of 100 ° C./sec.

In the present invention, in order to easily obtain high hardness by induction quenching, the microstructure before induction quenching, in particular, the amount of carbide which is hardly dissolved in the matrix by short-time heating by high frequency, is determined by determining the chemical composition by weight. %, C: 0.40 to 1.20%, an alloy steel containing 0.40 to 1.20%, and a major axis 10 present in an arbitrary 1 mm ² observation field of view in a portion corresponding to induction hardening of the cross section of the steel.
This indicates that it is necessary to regulate the amount of carbide having a size of not less than 60 μm with an appropriate amount of not more than 60 pieces.

[0049]

As described above, the high-hardness martensitic stainless steel for induction hardening of the present invention can easily be induction hardened and obtain high hardness by focusing on the amount of carbide. Can be done. INDUSTRIAL APPLICABILITY The present invention is widely applicable to mechanical elements such as precision equipment and medical equipment, which require high hardness and corrosion resistance. A great effect can be obtained for parts and odd-shaped parts.

Claims (13)

[Claims] 1. The chemical composition in weight%, C: 0.40 to 1.20
% Of alloy steel containing a major diameter of 1 mm ^{2 in} the observation field plane of an arbitrary 1 mm ^{2 at} the part corresponding to induction hardening of the steel cross section.
A high-hardness martensitic stainless steel for induction hardening, wherein the number of carbides of 0 μm or more is 60 or less. 2. The chemical composition in weight%, C: 0.40 to 1.20.
% High-hardness martensitic stainless steel for induction quenching, characterized in that the major axis of the carbide in the part corresponding to induction quenching in the cross section of the steel is 10 μm or less. 3. The chemical composition in weight%, C: 0.40 to 1.20
% Of alloy steel containing a major diameter of 1 mm ^{2 in} the observation field plane of an arbitrary 1 mm ^{2 at} the part corresponding to induction hardening of the steel cross section.
60 μm or less of carbide having a major axis of 5 μm or less with respect to the total cross-sectional area of carbide having a major axis of 10 μm or less.
A high-hardness martensitic stainless steel for induction hardening, wherein an area ratio of carbides of m or less exceeds 70%. 4. The chemical composition in% by weight, C: 0.40 to 1.20.
%, The major axis of the carbide in the part corresponding to induction hardening of the steel cross section is 10 μm or less, and the major axis 5 μm with respect to the total cross-sectional area of the remaining major carbide 10 μm or less.
A high-hardness martensitic stainless steel for induction hardening, wherein an area ratio of carbides of m or less exceeds 70%. 5. The method according to claim 1, wherein the amount of C is% by weight.
A high-hardness martensitic stainless steel for induction hardening, characterized by being an alloy steel substituted with 0.50 to 0.75% by weight. 6. The chemical composition in weight%, Cr: 9.0-2.
2. The alloy according to claim 1, wherein said alloy steel contains 0.0%.
5. A high-hardness martensitic stainless steel for induction hardening according to any one of items 1 to 4. 7. The chemical composition in weight%, Cr: 9.0 to 2
6. An alloy steel containing 0.0%.
The high-hardness martensitic stainless steel for induction hardening described in 1. 8. The chemical composition in weight%, Si: 0.01-1.
7. The composition according to claim 6, wherein the composition contains 50% and Mn: 0.03 to 2.00%, with the balance being Fe and unavoidable impurities.
7. A high hardness martensitic stainless steel for induction hardening according to 7. 9. The chemical composition in weight%, Si: 0.31-1.
7. The composition according to claim 6, wherein the content of Mn is 0.31 to 1.00% and the balance is Fe and unavoidable impurities.
7. A high hardness martensitic stainless steel for induction hardening according to 7. 10. The high-hardness martensitic stainless steel for induction hardening according to claim 6, wherein the Cr content is replaced by 11.00 to 13.50% by weight. 11. A chemical composition expressed in% by weight, wherein Mo: 0.05
2.00%, W: 0.01-1.00%, Co: 0.01-1.00%,
V: 0.01 to 0.50%, Nb: 0.01 to 0.50%, Ti: 0.0030
~ 0.1000%, B: 0.0005 ~ 0.0100%, Al: 0.030 ~ 0.
The high-hardness marten for induction hardening according to claim 6, wherein one or two or more of N and 0.0200 to 0.1500% are contained, and the balance is composed of Fe and inevitable impurities. Sight stainless steel. 12. A chemical composition represented by weight%, O: 0.0030
% Or less, S: 0.010% or less, P: 0.015% or less
The high-hardness martensitic stainless steel for induction hardening according to any one of claims 6 to 10, wherein the steel contains one or more kinds and the balance consists of Fe and unavoidable impurities. 13. A chemical composition represented by weight%, wherein Mo: 0.05
2.00%, W: 0.01-1.00%, Co: 0.01-1.00%,
V: 0.01 to 0.50%, Nb: 0.01 to 0.50%, Ti: 0.0030
~ 0.1000%, B: 0.0005 ~ 0.0100%, Al: 0.030 ~ 0.
100%, N: One or more of 0.0200 to 0.1500%, and O: 0.0030% or less, S: 0.010%,
The high-hardness martensitic stainless steel for induction hardening according to any one of claims 6 to 10, wherein one or more of P: 0.015% or less are contained, and the balance consists of Fe and inevitable impurities. .