JPH0860236A - Manufacturing method of high precision parts - Google Patents

Abstract

(57) [Summary] [Object] To provide a high-precision component capable of improving quietness by achieving high precision without inconvenience as in the prior art. [Structure] C: 0.03 to 0.30%, Si: 0.50
% Or less (including 0%), Mn: 0.3 to 3.0%, P:
0.030% or less (including 0%), S: 0.035% or less (including 0%), Al: 0.015 to 0.06%,
N: 0.005 to 0.03%, respectively, and if necessary Cr, Mo, V, Ni, Cu, Ti, Nb, Ca, Zr
After carburizing the intermediate work part formed by using a case-hardening net containing Fe and unavoidable impurities, the balance of which is equal to the critical cooling rate V _{c1 to} V _C4 (° C /
Second) after cooling to room temperature at a cooling rate V of less than or equal to the following, after which correction processing for correcting the shape of the component is performed if desired, and then reheating to a temperature lower than the first carburizing treatment temperature in a carburizing atmosphere or carbonitriding atmosphere. , Quenching process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a part for various machine structures, in which a carburizing process is applied to the surface layer part in order to improve wear resistance and fatigue resistance, and the hardness of the surface layer part is required to be increased. For example, gears, shafts used in various parts of automobiles,
The present invention relates to a method for manufacturing a constant velocity joint or the like with high accuracy. In the following description, application examples to automobile gears will be described as representative examples, but the parts of the present invention are not limited to automobile gears or automotive parts, and distortion due to heat treatment may be small. It can be applied to all desired mechanical structural parts.

[0002]

2. Description of the Related Art At present, transportation machines such as automobiles and two-wheeled vehicles are required to have improved fuel efficiency and quietness. Among them, it is effective to reduce the size and weight of parts for improving fuel efficiency, but for that purpose, it is necessary to increase the strength of parts. Further, in order to improve quietness, it is effective to improve the precision of parts, but for that purpose, it is an essential requirement to reduce the strain after heat treatment.

As described above, in order to solve the problem of improving the fuel efficiency of automobiles, it is necessary to promote the strengthening of automobile parts. However, the present inventors have found that the high strength of gear parts and various shaft parts is high. Various studies have been carried out from the viewpoint of improvement. From such a viewpoint, the present inventors have proposed a method for improving fatigue strength by performing shot peening after carburizing and tempering to give residual stress to the tooth root portion of a gear (Japanese Patent Laid-Open No. 1-306521). issue).

On the other hand, from the viewpoint of improving the quietness during the operation of the automobile, as described above, it is required that the heat treatment strain after carburizing and quenching is small, but the purpose is to reduce the heat treatment strain. The technology used is 200 after carburizing and diffusion.
Cooling and holding in nitrate or nitrite at about ℃, further cooling by air quenching method, while adjusting the chemical composition,
A method of reducing heat treatment strain by performing an optimum carburizing treatment (for example, JP-A-2-298250) has been proposed. Further, a low-strain carburizing steel (for example, Japanese Patent Laid-Open No. 60-50795) that achieves a low strain by adjusting the content of C or Mn to define the critical cooling rate has also been proposed. However, the technologies proposed so far have little effect of reducing the heat treatment strain. By the way, the conventional carburized gear is manufactured by the following processes. Hot forging or cold forging → Machining → Hobbing → Shaving → Carburizing and quenching

In carrying out the above steps, the heat treatment strain (deformation amount) generated during carburizing and quenching is estimated in advance, and the expected deformation amount is shaving before carburizing and quenching. However, since the deformation amount and the variation due to the carburizing and quenching after the shaving process are large, it is difficult to improve the precision of the gear. Therefore, instead of carburizing and quenching after shaving as described above, the steel material is formed into a predetermined shape and gradually cooled after carburizing treatment, and subsequently subjected to correction processing for correcting the shape of the intermediate process part,
Further, a method has been proposed in which the precision of the carburized component is improved by reheating and quenching this intermediate component (for example, JP-A-5-320765).
issue). However, in this technique, the surface structure after carburizing and gradual cooling becomes a martensite structure or a mixed structure of (martensite + bainite), and the surface hardness becomes high. Is called) and the production cost becomes high.

[0006]

The present invention has been made in order to solve these technical problems, and its purpose is to avoid the disadvantages of the prior art.
It is to provide a high-precision component that can improve quietness by achieving high precision.

[0007]

The present invention capable of achieving the above-mentioned object is that C: 0.03 to 0.30%, Si: 0.50.
% Or less (including 0%), Mn: 0.3 to 3.0%, P:
0.030% or less (including 0%), S: 0.035% or less (including 0%), Al: 0.015 to 0.06%,
N: 0.005 to 0.03% each, the balance is Fe and the unavoidable impurities. After the carburizing of the intermediate step parts molded using case hardening steel, the critical cooling represented by the following (1) Cooling rate V (° C / sec) of speed V _c1 (° C / sec) or less
After cooling to room temperature at room temperature, if necessary, corrective processing to correct the shape of the part is performed, and then reheating to a temperature lower than the first carburizing temperature in a carburizing or carbonitriding atmosphere, and then performing quenching. It is a method of manufacturing a high-precision component having the gist. V _c1 = 10 ^k1 (1) where k1 = 0.61 + 1.00 [C] -0.45 [Mn] [C]: amount of surface carbon after carburizing (%) [Mn]: Mn content in case-hardening steel amount(%)

As the case-hardening steel used in the present invention, if necessary, in addition to the above components, a predetermined amount of Cr, Mo, V, N.
It is also effective to contain i, Cu, Ti, Nb, Ca, Zr and the like. Of these, particularly when Cr or Mo is contained, since these elements are elements that affect the hardenability of steel, the critical cooling rate V _c1 (° _C./second ) is set according to the content of these contained elements. Then, as the critical cooling rates V _{c2 to} V _c4 (° C./sec) represented by the following formulas (2) to (4),
As the critical cooling rate V _c2 ~V _c4 (℃ / sec) or less cooling rate V (° C. / sec) needs to be cooled to room temperature.

(When Cr is included) V _c2 = 10 ^k2 (2) where k2 = 0.61 + 1.00 [C] -0.45 [Mn] -0.69
[Cr] [C]: amount of surface carbon after carburizing (%) [Mn]: Mn content in case-hardened steel (%) [Cr]: Cr content in case-hardened steel (%) (Mo case of ^{_{containing) V c3 = 10 k3 ... (}} 3) where, k3 = 0.61 + 1.00 [C ] -0.45 [Mn] -2.10
[Mo] [C]: amount of surface carbon after carburization (%) [Mn]: Mn content (%) in case-hardened steel [Mo]: Mo content (%) in case-hardened steel (Cr and When Mo is included) V _c4 = 10 ^k4 (4) However, k4 = 0.61 + 1.00 [C] -0.45 [Mn] -0.69
[Cr] -2.10 [Mo] [C]: Surface carbon content after carburization (%) [Mn]: Mn content in case-hardened steel (%) [Cr]: Cr content in case-hardened steel ( %) [Mo]: Mo content (%) in case-hardening steel

[0010]

The present inventors have studied from various angles from the viewpoint of realizing the above high-precision parts. As a result, the chemical components of the case-hardening steel to be used are specified, and the cooling conditions after the carburizing treatment, especially the manufacturing conditions, are determined by the amount of carbon on the surface after the carburizing treatment and the contents of Mn, Cr, Mo, etc. in the case-hardening steel. The inventors have found that the above objects can be achieved satisfactorily if they are rigorously defined and the heat treatment conditions thereafter are appropriately set, and the present invention has been completed. First, the reasons for limiting the chemical components in the invention are as follows.

C: 0.03 to 0.30% C is an element useful for ensuring the strength of the core of the component, and for this purpose, addition of 0.03% or more is required. However, if added excessively, the toughness deteriorates, and the machinability and cold forgeability deteriorate and the workability deteriorates.
It should be 0.3% or less. A more preferable range of the C content is about 0.10 to 0.25%.

Si: 0.50% or less (including 0%) Si promotes intergranular oxidation, causes a decrease in bending fatigue strength, and deteriorates cold forgeability, so 0.50% or less. Need to be suppressed. From the viewpoint of improving bending fatigue strength, the more preferable range of Si content is 0.1.
0% or less.

Mn: 0.3-3.0% Mn is an important element as a deoxidizing agent and for securing strength and hardenability, and for that purpose, 0.3% or more is required to be added. However, if it exceeds 3%, the cold workability deteriorates,
And the segregation to the grain boundaries increases, and the grain boundary strength decreases,
As a result, the upper limit is set to 3 to reduce bending fatigue strength.
Defined as%. The more preferable range of Mn content is 0.5
It is about 2.5%.

P: 0.030% or less (including 0%) P segregates at the grain boundaries to lower the toughness.
The upper limit was set to 0.030%. From the viewpoint of improving the toughness, the more preferable range of the P content is 0.015% or less. S: 0.035% or less (including 0%) S is a machinability improving element, but since it adversely affects the cold forgeability, its addition amount needs to be 0.035% or less.

Al: 0.015 to 0.06% Al is an element contained in steel as a deoxidizing agent and binds N in steel to form AlN, which prevents coarsening of crystal grains. Is an effective element. In order to exert this effect, it is necessary to add 0.015% or more, but 0.06%
Since the above effect will be saturated from around the point where%,
The upper limit was set to 0.06%. A more preferable range of Al content is about 0.02 to 0.05%.

N: 0.005 to 0.03% N is Al and V, Ti, and optionally added in the steel.
It is an element effective in forming a nitride by combining with Nb and the like and suppressing the coarsening of crystal grains. In order to exert such effects, it is necessary to add 0.005% or more.
However, since the above effect becomes saturated around 0.03%, the upper limit was set to 0.03%. A more preferable range of N content is 0.007-0.
It is about 020%.

The case-hardening net used in the present invention has the above-mentioned elements as basic components and the balance Fe and unavoidable impurities. If necessary, a predetermined amount of Cr, Mo, V, Ni, C is used.
You may add u, Ti, Nb, etc. The reasons for limiting the range of addition when adding these elements are as follows.

Cr: 0.03 to 1.5% Cr is an element useful for improving the hardenability, and it is necessary to add 0.03% or more to bring out this effect.
%, The grain boundary oxidation of the carburized layer becomes large, so 1.
The upper limit was set at 5%. The more preferable range of the Cr content is about 0.3 to 1.5%.

Mo: 0.07 to 1.0% Mo is an element useful for suppressing the grain boundary oxide layer and ensuring hardenability, and it is necessary to add 0.07% or more in order to exert its effect. is there. However, even if added in excess of 1.0%, the above effect is saturated, so the upper limit was set to 1.0%. A more preferable range of Mo content is about 0.15 to 0.85%.

V: 0.03 to 0.5% V is an element effective for grain refinement by combining with C or N to form carbon / nitride (carbide, nitride and carbonitride). . Further, it is an element effective in reducing the hardness of the carburized layer by aggregating carbides to coarsen the lamellar spacing of pearlite during the first carburizing treatment. In order to exert such effects, it is necessary to add 0.03% or more, but if added excessively, the machinability will decrease, so the upper limit is 0.5%.
I decided.

Ni: 0.20 to 2.5% Ni is an element useful for making the structure after carburization fine, ensuring stable core hardness, and improving hot workability. In order to exert these effects, it is necessary to add 0.20% or more, but if it exceeds 2.5%, this effect saturates, so 2.5% was defined as the upper limit. A more preferable range of Ni content is about 0.3 to 2.5%.

Cu: 0.30 to 2.0% Cu is an element useful for preventing grain boundary oxidation and improving corrosion resistance, and it is necessary to add 0.30% or more to exert this effect. , 2.0%, the effect is saturated, so 2.0% was defined as the upper limit. However, when Cu is added alone, the hot workability tends to deteriorate. Therefore, when Cu is added, at least Ni having the effect of improving the hot workability needs to be added within the above range. A more preferable range of Cu content is about 0.30 to 1.00%.

Ti: 0.005 to 0.1% Ti combines with N to form a nitride, which is a useful element for refining crystal grains. To exert this effect, 0.005
%, It is necessary to add 0.1% or more. However, if it is added in excess of 0.1%, this effect reaches saturation, so 0.1% was set as the upper limit. More preferably, it is about 0.005 to 0.02%.

Nb: 0.005 to 0.1% Nb is an element effective for suppressing coarsening of crystal grains by combining with C and N in steel to form carbon / nitride. In order to exert this effect, 0.005% or more is required to be added, but excessive addition causes a reduction in cold workability, so 0.1% was set as the upper limit. More preferably 0.00
It is about 5 to 0.05%.

Ca: 0.0005 to 0.08% and /
Alternatively, Zr: 0.002-0.08% Ca is an element effective for improving machinability by wrapping hard inclusions with soft inclusions, and Zr spheroidizing MnS. is there. In order to exert these effects, it is necessary to add 0.0005% or more of Ca and 0.002% or more of Zr. However,
Even if added in excess of 0.08%, the effect is saturated, so their upper limit was made 0.08%. The preferable range of the content of these elements is 0.005 to Ca.
It is about 0.020% and Zr is about 0.005 to 0.05%.

The object of the present invention is not achieved only by specifying the chemical composition of the case-hardening steel, but it is also necessary to satisfy the requirements of the above-mentioned manufacturing conditions. Next, the reason for specifying the manufacturing conditions will be described.

In the present invention, the cooling rate V (° C./second) after the carburizing treatment is set to the critical cooling rate V _{c1 to} V _c4 (° C./second) represented by any one of the expressions (1) to (4). ) It is necessary to cool to room temperature as follows. That is, based on the amount of surface carbon after carburizing and the contents of Mn, Cr, Mo, etc. in the steel material, the critical cooling rate V _{c1 to} V at which bainite precipitates
_c4 (° C / s) is specified, and the cooling rate V (° C /
(Sec) is set to the critical cooling rate V _{c1 to} V _c4 (° C./sec) or less to make the surface texture of the carburized component a pearlite texture. Thus, by making the surface structure a pearlite structure, a hardness lower than that of the bainite structure or martensite structure can be achieved, and the shaving life can be improved. From a viewpoint of the time to achieve a time reduction of the cooling step after the carburizing treatment, after carburization, 300 with the critical cooling rate V _c1 ~V _c4 (℃ / sec) or less cooling rate V which bainite is precipitated
It is preferable to cool the furnace to about 400 ° C. and then to cool it to room temperature by forced cooling. In the above formulas (1) to (4), the “carbon amount on the surface after carburizing treatment” means 0.
It is a value obtained by collecting chips from a portion of 05 mm and analyzing by chemical analysis (infrared absorption method: JIS G 1211-1979).

In the present invention, after cooling as described above, a correction process for correcting the shape of the component as desired is performed,
After that, it is necessary to "reheat in a carburizing atmosphere or carbonitriding atmosphere at a temperature lower than the first carburizing temperature and then perform quenching treatment". The residual stress applied during machining is released during the heating of the first carburizing process. Since the strain caused by the residual stress is corrected by a correction process as desired, the residual stress does not affect the strain during heating in the carburizing treatment or carbonitriding treatment. However, at the time of reheating, it is necessary to suppress the strain generated by thermal stress and creep, so the reheating and quenching temperature must be lower than the first carburizing temperature.

The present invention will be described in more detail with reference to the following examples. However, the following examples are not intended to limit the present invention, and any modification of the present invention can be made without departing from the spirit of the preceding and following claims. It is included in the technical scope.

[0030]

EXAMPLES Steel materials (steel materials Nos. 1 to 35) having the chemical compositions shown in Tables 1 and 2 were manufactured by the following steps. (Manufacturing process) 150 kg vacuum melting → φ65 mm hot forging → solution treatment (1250 ° C × 1 hr → AC) → normalizing treatment (850 ° C × 1 hr → AC)

[0031]

[Table 1]

[0032]

[Table 2]

After hot forging was performed using the rolled steel bar of the above steel material, a spur gear (intermediate part) having the following specifications was prepared by machining. (Specifications of gear) Number of teeth: 22 Module: 2.0 Tooth width: 20mm

Final parts were prepared from the above spur gears (intermediate parts) by the following steps. At this time, the carburizing and quenching treatment process in step A (conventional step) is as shown in FIG. Further, the carburizing and cooling treatment process and the reheating and quenching treatment process in step B (step of the present invention) are
This is as shown in FIGS. 2 and 3, respectively. 1 and 2, the carbon potential value (CP
The value) was 0.9 to 1.0. The heat treatment conditions (t _{1 to} t ₄ ) of each of the above processes were set to the cooling rate V after the carburizing treatment, the RX gas flow rate (m ³ / h) at the time of reheating and quenching, NH
_{It is} shown in Table 3 below together with ₃ gas flow rates (l / min).

Step A (conventional step): Hobbing → shaving → carburizing and quenching (Fig. 1) → tempering Step B (inventive process): hobbing → carburizing and cooling (Fig. 2) → shaving → reheating quenching (Fig. 3) → tempering

[0036]

[Table 3]

After tempering treatment at 160 ° C. × 1 hr → AC, before and after heat treatment (after shaving and after tempering)
The tooth trace change amount of the gear was measured (the number of measurements: 30 times).
The results are shown as the surface carbon content and the critical cooling rates V _{c1 to} V _c4 (° C
/ Sec), and the cooling rate V after carburizing treatment, etc. are shown in Tables 4 and 5 below. In addition, the steel material No. 1-4, 32-
Table 6 shows the results of evaluating the shaving life of the sample No. 35 after carburizing and cooling. The shaving life was evaluated by the number of teeth when the tooth profile error of the gear deviated from JIS class 3.

[0038]

[Table 4]

[0039]

[Table 5]

[0040]

[Table 6]

As is clear from Tables 4 to 6, the examples of the present invention (steel materials Nos. 1 to 25) are excellent in shaving life, and in addition, the tooth trace variation and its variation are small. It can be seen that high precision parts have been achieved.

On the other hand, the comparative examples (steel materials Nos. 26 to 35) lacking any of the requirements specified in the present invention are:
Poor in at least one property. That is,
Steel material No. In Nos. 26 to 28, the chemical components were within the range specified in the present invention, but since they were produced by the conventional process, the tooth muscle change amount and its variation were large. In addition, the steel material No. In Nos. 29 to 31, the chemical composition was within the range specified by the present invention, but the reheating temperature was higher than the first heat treatment temperature, and therefore the tooth muscle change amount and its variation were large. Steel material No. 32,3
In 3, the chemical composition is within the range specified in the present invention,
Since the cooling rate after carburization does not satisfy the requirements specified in the present invention, the shaving life is significantly reduced. Steel material N
o. In Nos. 34 and 35, since the element contents of Mn, Cr, Mo, etc. are out of the ranges specified in the present invention, the cooling rate V becomes larger than the critical cooling rates V _{c1 to} V _c4 , and the shaving life becomes longer. It has dropped significantly.

[0043]

The present invention is constructed as described above, and it is possible to realize a high-precision component having less distortion and its variation after reheating and quenching. This high-precision component can reduce the gear noise of an automobile, for example, and can improve the quietness. Further, since the tool life can be improved, highly efficient mass production is possible. Furthermore, it is possible to handle high loads by reducing tooth contact defects due to higher precision,
It is possible to improve wear resistance and fatigue resistance without applying a means for increasing strength such as shot peening.

[Brief description of drawings]

FIG. 1 is a diagram showing a heat treatment pattern during carburizing and quenching treatment in a conventional process.

FIG. 2 is a diagram showing a heat treatment pattern during carburizing and cooling treatment in the process of the present invention.

FIG. 3 is a diagram showing a heat treatment pattern during reheating and quenching in the process of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C22C 38/00 301 N 38/06 38/18 38/38 38/58 C23C 8/22 8/32 8/80 (72) Inventor Shinichi Yasuki 2 Nadahama Higashi-cho, Nada-ku, Kobe-shi, Hyogo Stock Company Kobe Steel Works Kobe Steel Works (72) Inventor Yoshitake Matsushima 2 Nada-hama Higashi-cho, Nada-ku, Kobe City, Hyogo Prefecture Kobe Steel Works Kobe Steel Works

Claims (10)

[Claims] 1. C: 0.03 to 0.30% (meaning weight%; the same applies hereinafter), Si: 0.50% or less (including 0%), Mn: 0.3 to 3.0%, P: 0.030% or less (including 0%), S: 0.035% or less (including 0%), Al: 0.015 to 0.06%, N: 0.005
After carburizing the intermediate step parts formed by using case-hardening steel containing 0.03% to 0.03% and the balance being Fe and inevitable impurities, the critical cooling rate V represented by the following formula (1)
Cool to room temperature at a cooling rate V (° C / sec) of _c1 (° C / sec) or less, then reheat to a temperature lower than the first carburizing temperature in a carburizing or carbonitriding atmosphere, and then perform quenching treatment. A method for manufacturing a high-precision component, which is characterized by the above. V _c1 = 10 ^k1 (1) where k1 = 0.61 + 1.00 [C] -0.45 [Mn] [C]: amount of surface carbon after carburizing (%) [Mn]: Mn content in case-hardening steel amount(%) 2. C: 0.03 to 0.30%, Si: 0.
50% or less (including 0%), Mn: 0.3 to 3.0%,
P: 0.030% or less (including 0%), S: 0.035
% Or less (including 0%), Al: 0.015 to 0.06
%, N: 0.005 to 0.03%, and Cr:
After carburizing an intermediate process part containing 0.03 to 1.5% and a case-hardening steel with the balance being Fe and unavoidable impurities, a critical cooling rate represented by the following formula (2) After cooling to room temperature at a cooling rate V (° C / sec) of V _c2 (° C / sec) or less, and then reheating to a temperature lower than the first carburizing temperature in a carburizing atmosphere or carbonitriding atmosphere, quenching treatment is performed. A method for manufacturing a high-precision component, which is characterized by carrying out. V _c2 = 10 ^k2 (2) where k2 = 0.61 + 1.00 [C] -0.45 [Mn] -0.69
[Cr] [C]: amount of surface carbon after carburizing (%) [Mn]: Mn content in case-hardened steel (%) [Cr]: Cr content in case-hardened steel (%) 3. C: 0.03 to 0.30%, Si: 0.
50% or less (including 0%), Mn: 0.3 to 3.0%,
P: 0.030% or less (including 0%), S: 0.035
% Or less (including 0%), Al: 0.015 to 0.06
%, N: 0.005-0.03%, respectively, and Mo:
After carburizing the intermediate step parts containing 0.07 to 1.0% and the case-hardening steel with the balance being Fe and unavoidable impurities, the critical cooling rate represented by the following formula (3) After cooling to room temperature at a cooling rate V (° C / sec) of V _c3 (° C / sec) or less, and then reheating to a temperature lower than the first carburizing temperature in a carburizing atmosphere or carbonitriding atmosphere, quenching treatment is performed. A method for manufacturing a high-precision component, which is characterized by carrying out. V _c3 = 10 ^k3 (3) where k3 = 0.61 + 1.00 [C] -0.45 [Mn] -2.10
[Mo] [C]: Surface carbon content (%) after carburizing treatment [Mn]: Mn content (%) in case-hardened steel [Mo]: Mo content (%) in case-hardened steel 4. C: 0.03 to 0.30%, Si: 0.
50% or less (including 0%), Mn: 0.3 to 3.0%,
P: 0.030% or less (including 0%), S: 0.035
% Or less (including 0%), Al: 0.015 to 0.06
%, N: 0.005 to 0.03%, and Cr:
After carburizing the intermediate step parts molded using case-hardening steel containing 0.03 to 1.5% and Mo: 0.07 to 1.0% and the balance being Fe and unavoidable impurities, Cooling to room temperature at a cooling rate V (° C / sec) that is equal to or lower than the critical cooling rate V _c4 (° C / sec) represented by the equation (4), and then in a carburizing atmosphere or carbonitriding atmosphere than the first carburizing temperature A method of manufacturing a high-precision component, characterized by performing quenching after reheating to a low temperature. V _c4 = 10 ^k4 (4) where k4 = 0.61 + 1.00 [C] -0.45 [Mn] -0.69
[Cr] -2.10 [Mo] [C]: Surface carbon content after carburization (%) [Mn]: Mn content in case-hardened steel (%) [Cr]: Cr content in case-hardened steel ( %) [Mo]: Mo content (%) in case-hardening steel 5. The method for producing a high precision component according to claim 1, wherein the case-hardening steel further containing V: 0.03 to 0.5% is used. 6. The method for producing a high precision component according to claim 1, wherein the case-hardening steel further containing Ni: 0.20 to 2.5% is used. 7. The method for producing a high-precision component according to claim 6, wherein the case-hardening steel further containing Cu: 0.30 to 2.0% is used. 8. The method for producing a high-precision component according to claim 1, wherein the case-hardening steel further containing Ti: 0.005 to 0.1% is used. 9. The method for producing a high-precision component according to claim 1, wherein the case-hardening steel further containing Nb: 0.005 to 0.1% is used. 10. Ca: 0.0005 to 0.08%
And / or using a case-hardening steel containing Zr: 0.002 to 0.08%, The method for producing a high-precision component according to any one of claims 1 to 9.