JP2023174901A - Contact stress estimation method for rolling component, contact estimation program for rolling component, and contact stress estimation device for rolling component - Google Patents

Abstract

To provide a method for estimating a fatigue level of a rolling component, a device for estimating the fatigue level of the rolling component, and a program for estimating the fatigue level of a rolling component, which are capable of estimating the fatigue level of the rolling component with high accuracy.SOLUTION: A method for estimating a fatigue level of a rolling component includes: a step (S110) of acquiring data for estimating the degree of fatigue of the rolling component from the rolling component subjected to repeated loads due to rotation; a step (S120) of determining whether or not a structural change has occurred in a fatigued part of the rolling component based on the data obtained in the step (S110); and steps (S131 to S134, and S141) for estimating a first fatigue degree regarding internally originating damage of the rolling component based on the determination result in the step (S120) and the data obtained in the step (S110).SELECTED DRAWING: Figure 4

Description

The present invention relates to a rolling component fatigue level estimation method, a rolling component fatigue level estimation device, a rolling component fatigue level estimation program, and a rolling component contact stress estimation method.

It is known that the life of a rolling bearing (hereinafter also referred to as a bearing) depends on operating conditions such as load and lubrication conditions, and material properties such as hardness, structure, and residual stress. Conventionally, the life of a bearing has been estimated using a life calculation formula that can be calculated from operating conditions and material properties. This calculation formula estimates how long a bearing can be used under certain conditions, or under what conditions the bearing should be used to avoid damage during the required usage period. is used for. Generally, bearings are used under usage conditions set based on a lifespan calculation formula. Therefore, if the bearing is used under the assumed conditions, the life of the bearing should not be a problem.

However, bearing life is often an issue in the market. One of the reasons for this is thought to be that the actual bearings are used in unexpected environments and conditions. Therefore, a method has been proposed for estimating the fatigue level of rolling bearings based on the results of surveys of actually used bearings.

For example, in order to prevent internally originating damage that occurs in bearings that are used under good lubrication conditions, a contact stress estimation method obtained by X-ray analysis disclosed in Non-Patent Document 1 can be used to There is a method of determining the dynamic equivalent load and estimating the fatigue level from the calculated life calculated from the dynamic equivalent load and the past usage time (see Patent Document 1). The fatigue degree estimation method described above takes advantage of the fact that there is a correspondence between the stress repeatedly applied to the raceway surface on which a load acts in rolling parts and the residual stress generated by that stress. Estimating the load on rolling parts from stress distribution. Thereafter, the lifespan is calculated based on the estimated load, and the degree of fatigue is estimated from the ratio of the lifespan to the number of rotations or operating hours of the rolling parts.

Furthermore, a method has been proposed for estimating the fatigue level of internally originating damage in rolling parts based on the relationship between the analysis value of X-ray stress measurement and the rolling fatigue level (see Patent Document 2).

JP2011-069681A Special Publication No. 63-34423

“Application of X-ray stress measurement to bearing failure analysis”, Masuyuki Tsushima et al., Bearing Engineer No. 49, pp. 25-34 (1984)

In general, the progress of rolling contact fatigue in rolling parts, such as the rolling elements of rolling bearings, is as follows: the first stage is up to ¹⁰³ rotations, when residual stress is generated, and the rolling fatigue stage occurs after residual stress is generated. occurs, but the half-width, amount of retained austenite, and residual stress do not change; the third stage is a structural change that occurs in the region where relatively high stress was applied during rolling contact fatigue, and the resulting redistribution of residual stress. It can be divided into Therefore, the residual stress generated in the rolling component before the third stage accurately reflects the load conditions that were applied to the rolling component at the initial stage of use. On the other hand, from the third stage onward, redistribution of residual stress occurs as the number of rotations increases due to changes in the structure of the material in the stress-applied region of the rolling component. For this reason, in rolling parts where rolling fatigue has progressed to the third stage or later, the load estimation of the rolling parts due to residual stress becomes inaccurate, and the fatigue estimated by the method disclosed in Patent Document 1 mentioned above becomes inaccurate. accuracy may decrease.

In addition, in the fatigue degree estimation method disclosed in Patent Document 2, X-ray analysis (for example, half-width and residual austenite content) is performed to detect structural changes in the material at depths where fatigue is likely to occur inside rolling parts. measurement). Thereafter, the degree of fatigue of the rolling parts is estimated using a database of the relationship between changes in data obtained by the X-ray analysis and the number of rotations of the rolling parts. This method can be applied to estimate the degree of fatigue in the third and subsequent stages, where the structure of the material gradually changes depending on the number of rotations of the rolling component. On the other hand, in the second stage, where the structural changes due to rolling fatigue do not progress even if the number of rotations of the rolling parts changes, the data detected by X-ray analysis that corresponds to the structural changes even if the number of rotations of the rolling parts changes. It does not change. For this reason, in the method for estimating the degree of fatigue of rolling parts disclosed in Patent Document 2, it is difficult to estimate the degree of fatigue with high accuracy regarding rolling fatigue that has progressed to the second stage.

Therefore, an object of the present invention is to provide a method for estimating the fatigue level of rolling parts, a device for estimating the fatigue level of rolling parts, and a fatigue level estimation apparatus for rolling parts, which are capable of estimating the fatigue level of rolling parts with high accuracy. The goal is to provide programs.

Another object of the present invention is to provide a method for estimating contact stress of rolling parts, which can be used to estimate the degree of fatigue of rolling parts with high accuracy.

A rolling component fatigue level estimation method according to the present disclosure includes the step of acquiring data for estimating the rolling component fatigue level from a rolling component to which repeated loads due to rotation are applied. The obtaining step includes a step of obtaining first data regarding the microstructure of the rolling component, and a step of obtaining first data regarding the microstructure of the rolling component, and first data that is measured data of X-ray analysis values regarding the rolling component by irradiating the fatigue part of the rolling component with X-rays. 2. Obtaining data. The method for estimating the fatigue level of rolling parts further includes a step of determining whether or not a structural change has occurred in a fatigued part of the rolling part based on the data obtained in the acquiring step; and a step of estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result and the data obtained in the obtaining step. The step of estimating the first degree of fatigue includes a step of estimating the load acting on the rolling component based on the second data when it is determined that no structural change has occurred in the determining step; A step of calculating the lifespan based on the usage conditions of the rolling component, and a step of calculating a first degree of fatigue of the rolling component from the number of rotations and the lifespan of the rolling component are performed. In addition, in the step of estimating the first fatigue degree, if it is determined that a tissue change has occurred in the determining step, the second fatigue degree is estimated based on the relationship between the predetermined second data and the first fatigue degree. A step of estimating a first fatigue level from the data is performed.

A fatigue degree estimation program according to the present disclosure is a fatigue degree estimation program for rolling parts, and includes a step of, in a computer, acquiring data for estimating the fatigue degree from rolling parts to which repeated loads due to rotation are applied. Let it run. The obtaining step includes obtaining first data regarding the microstructure of the rolling component, and second data, which is measured data of X-ray analysis values regarding the rolling component, by irradiating X-rays to fatigued parts of the rolling component. and obtaining data. The above fatigue degree estimation program includes a step in which a computer determines whether or not a structural change has occurred in a fatigued part of a rolling component based on the data obtained in the acquisition step, and a determination result in the determination step. and a step of estimating a first fatigue degree regarding internally originating damage of the rolling component based on the data obtained in the obtaining step. The step of estimating the first degree of fatigue includes a step of estimating the load acting on the rolling component based on the second data when it is determined that no structural change has occurred in the determining step; A step of calculating the lifespan based on the usage conditions of the rolling component, and a step of calculating a first degree of fatigue of the rolling component from the number of rotations and the lifespan of the rolling component are performed. In the step of estimating the first fatigue degree, if it is determined that a tissue change has occurred in the determining step, based on the predetermined relationship between the second data and the first fatigue degree, A step of estimating a first fatigue level is performed.

A rolling component fatigue level estimating device according to the present disclosure includes a determining unit, a load estimating unit, a life calculating unit, a first fatigue level calculating unit, and a first fatigue level estimating unit. The determination unit is configured to obtain first data regarding the microstructure of the rolling component and second data that is measured data of X-ray analysis values regarding the rolling component obtained by irradiating a fatigued portion of the rolling component with X-rays. Based on at least one of the following, it is determined whether or not a structural change has occurred in the fatigued part of the rolling component. The load estimating unit estimates the load acting on the rolling component based on the second data when the determining unit determines that no tissue change has occurred. The life calculation unit calculates the life based on the load and the usage conditions of the rolling parts. The first fatigue degree calculation unit calculates the first fatigue degree of the rolling component from the number of rotations and the life of the rolling component. The first fatigue degree estimating section calculates the first fatigue degree from the second data based on the relationship between the predetermined X-ray analysis value and the first fatigue degree when the determining section determines that a tissue change has occurred. Estimate fatigue level.

A rolling component fatigue level estimation method according to the present disclosure includes the step of acquiring data for estimating the rolling component fatigue level from a rolling component to which repeated loads due to rotation are applied. The obtaining step includes a step of obtaining first data regarding the microstructure of the rolling component, and a step of obtaining first data regarding the microstructure of the rolling component, and first data that is measured data of X-ray analysis values regarding the rolling component by irradiating the fatigue part of the rolling component with X-rays. 2. Obtaining data. The method for estimating the fatigue level of rolling parts further includes a step of determining whether or not a structural change has occurred in a fatigued part of the rolling part based on the data obtained in the acquiring step; and a step of estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result and the data obtained in the obtaining step. The second data includes distribution data in the depth direction of X-ray analysis values regarding the rolling component. The step of estimating the first degree of fatigue includes a step of estimating the load acting on the rolling component based on the second data when it is determined that no structural change has occurred in the determining step; A step of calculating the lifespan based on the usage conditions of the rolling component, and a step of calculating a first degree of fatigue of the rolling component from the number of rotations and the lifespan of the rolling component are performed. In the judgment step, if it is determined that a tissue change has occurred, a step of estimating the load acting on the rolling parts based on the distribution data in the depth direction, and the load and usage conditions of the rolling parts. and a step of calculating a first fatigue degree of the rolling component from the number of rotations and the life of the rolling component.

A fatigue degree estimation program according to the present disclosure is a fatigue degree estimation program for rolling parts, and includes a step of, in a computer, acquiring data for estimating the fatigue degree from rolling parts to which repeated loads due to rotation are applied. Let it run. The obtaining step includes obtaining first data regarding the microstructure of the rolling component, and second data, which is measured data of X-ray analysis values regarding the rolling component, by irradiating X-rays to fatigued parts of the rolling component. and obtaining data. The above fatigue degree estimation program includes a step in which a computer determines whether or not a structural change has occurred in a fatigued part of a rolling component based on the data obtained in the acquisition step, and a determination result in the determination step. and a step of estimating a first fatigue degree regarding internally originating damage of the rolling component based on the data obtained in the obtaining step. The second data includes distribution data in the depth direction of X-ray analysis values regarding the rolling component. The step of estimating the first degree of fatigue includes a step of estimating the load acting on the rolling component based on the second data when it is determined that no structural change has occurred in the determining step; A step of calculating the lifespan based on the usage conditions of the rolling component, and a step of calculating a first degree of fatigue of the rolling component from the number of rotations and the lifespan of the rolling component are performed. In the step of estimating the first degree of fatigue, if it is determined that a structural change has occurred in the determining step, a step of estimating the load acting on the rolling component based on the distribution data in the depth direction. , a step of calculating a lifespan based on the load and usage conditions of the rolling component, and a step of calculating a first degree of fatigue of the rolling component from the number of rotations and the lifespan of the rolling component.

A fatigue level estimating device according to the present disclosure includes a determining unit, a load estimating unit, a life calculating unit, and a first fatigue level calculating unit. The determination unit is configured to obtain first data regarding the microstructure of the rolling component and second data that is measured data of X-ray analysis values regarding the rolling component obtained by irradiating a fatigued portion of the rolling component with X-rays. Based on at least one of the following, it is determined whether or not a structural change has occurred in the fatigued part of the rolling component. The load estimation unit estimates the load acting on the rolling component based on the second data. The life calculation unit calculates the life based on the load and the usage conditions of the rolling parts. The first fatigue degree calculation unit calculates the first fatigue degree of the rolling component from the number of rotations and the life of the rolling component. The second data includes distribution data in the depth direction of X-ray analysis values regarding the rolling component. The load estimating unit estimates the load acting on the rolling component based on the second data when the determining unit determines that no tissue change has occurred. The load estimating section estimates the load acting on the rolling component based on the distribution data in the depth direction when the determining section determines that a tissue change has occurred.

A method for estimating contact stress of a rolling component according to the present disclosure is to irradiate X-rays from the surface to the inside of a fatigued part of a rolling component, thereby diffracting annular diffracted X-rays with respect to a central angle at the fatigued part. The present invention includes a step of obtaining distribution data of strength variations in the depth direction, and a step of estimating contact stress repeatedly acting on a fatigued part of a rolling component based on the distribution data in the depth direction.

According to the above, it is possible to obtain a method for estimating the fatigue level of rolling parts, a device for estimating the fatigue level of rolling parts, and a program for estimating the fatigue level of rolling parts, which are capable of estimating the fatigue level of rolling parts with high accuracy. .

Moreover, according to the above, a method for estimating contact stress of rolling parts can be obtained, which can be used to estimate the degree of fatigue of rolling parts with high accuracy.

1 is a schematic diagram showing the configuration of a fatigue level estimation system according to Embodiment 1. FIG. FIG. 2 is a diagram showing the hardware configuration of the fatigue level estimation device shown in FIG. 1. FIG. FIG. 2 is a diagram showing the functional configuration of the fatigue level estimation device shown in FIG. 1. FIG. It is a flowchart showing the procedure of fatigue level estimation processing. FIG. 2 is a schematic diagram showing the configuration of a fatigue level estimation system according to a second embodiment. 6 is a diagram showing the functional configuration of the fatigue level estimation device shown in FIG. 5. FIG. It is a flowchart showing the procedure of fatigue level estimation processing. 12 is a flowchart representing a procedure of fatigue level estimation processing according to Embodiment 3. FIG. It is a graph which shows the depth distribution of the equivalent stress of residual stress. It is a graph which shows the relationship between the variation of the diffraction intensity obtained by circumferential incidence, and test time. It is a graph showing the relationship between the reduction rate of retained austenite and test time. FIG. 2 is a schematic diagram for explaining a coordinate system during X-ray measurement. It is a schematic diagram of diffraction X-ray. It is a schematic diagram of the measured annular diffraction X-ray. FIG. 3 is a schematic diagram for explaining variations in diffraction intensity. It is a graph which shows the depth direction distribution of the circumferential direction residual stress which is an X-ray measurement result of the 1st test piece. It is a graph which shows the depth direction distribution of the dispersion|variation of the diffraction intensity which is the X-ray measurement result of the 1st test piece. It is a graph which shows the depth direction distribution of the circumferential direction residual stress which is an X-ray measurement result of the 2nd test piece. It is a graph which shows the depth direction distribution of the dispersion|variation of the diffraction intensity which is the X-ray measurement result of the 2nd test piece. It is a graph which shows the estimation result of the contact stress of a 1st test piece. It is a graph which shows the estimation result of the contact stress of a 2nd test piece.

Embodiments of the present invention will be described below based on the drawings. In the following drawings, the same or corresponding parts are given the same reference numerals and the description thereof will not be repeated.

(Embodiment 1)
<Configuration of fatigue level estimation system>
FIG. 1 is a schematic diagram showing the configuration of a fatigue level estimation system according to the first embodiment. Referring to FIG. 1, the fatigue level estimation system includes a fatigue level estimation device 14, an irradiation unit 11, an X-ray detector 12, and a microstructure observation unit 23.

The irradiation unit 11 includes an X-ray tube installed so as to be able to face the rolling component 90, which is the bearing component to be inspected. The irradiation unit 11 irradiates the rolling component 90 with X-rays. The irradiated X-rays are irradiated along the arrow α so as to be incident on the rolling component 90 at a predetermined angle of incidence. The rolling component 90 includes a rolling element of a rolling bearing and a part or all of a bearing ring of a rolling bearing that is a bearing component for diagnosis or testing. For example, the X-rays may be applied to a part of the bearing ring of the rolling bearing.

The X-ray detector 12 detects annular X-rays (X-ray diffraction ring) diffracted by the rolling component 90. Specifically, the X-ray detector 12 includes a hole 12B formed in the center through which the X-rays irradiated from the irradiation section 11 pass, and a flat detection section 12A that can be opposed to the rolling component 90. including. For example, an X-ray CCD (Charge Coupled Device) can be used as the detection unit 12A. X-rays incident on the rolling component 90 along the arrow α are diffracted to form a conical surface β, and reach the detection unit 12A. Then, in the detection unit 12A, the X-ray diffraction ring is detected by a signal having an intensity corresponding to the intensity of the X-ray output from each pixel.

The microstructure observation unit 23 measures the state of the microstructure of the material constituting the rolling component 90. As the microstructure observation section 23, for example, an optical microscope can be used. The surface of the rolling component 90 to be measured may be, for example, a cross section of a portion of a bearing ring of a rolling bearing or a cross section of a rolling element.

The fatigue level estimating device 14 estimates the fatigue of the rolling component 90 based on the observation results of the X-ray diffraction ring detected by the X-ray detector 12 and the microstructure of the rolling component 90 detected by the microstructure observation unit 23. Estimate degree. The fatigue level estimation device 14 may be, for example, a small computer device (such as a personal computer).

<Hardware configuration of fatigue level estimation device>
FIG. 2 is a diagram showing the hardware configuration of the fatigue level estimation device shown in FIG. 1. The fatigue level estimation device 14 includes an input section 17 , a CPU (Central Processing Unit) 15 , a memory 16 , and a display section 18 .

The measurement results of the microstructure observation section 23 and the detection results of the X-ray detector 12 are input to the input section 17 . The memory 16 can store a fatigue level estimation program and the like. The CPU 15 uses the data input to the input unit 17 to execute a fatigue level estimation program stored in the memory 16. The display unit 18 displays the fatigue level estimation result by the CPU 15.

<Functional configuration of fatigue level estimation device>
FIG. 3 is a diagram showing the functional configuration of the fatigue level estimation device shown in FIG. 1. The fatigue level estimating device 14 shown in FIG. section 33 , a first fatigue degree calculation section 34 , a first fatigue degree estimation section 41 , and a diagnosis section 70 . The storage unit 61 is realized by the memory 16. The control section 60, the data preparation section 21, the judgment section 31, the load estimation section 32, the life calculation section 33, the first fatigue degree calculation section 34, the first fatigue degree estimation section 41, and the diagnosis section 70. is realized by the CPU 15 executing a fatigue level estimation program stored in the memory 16.

<Steps for fatigue level estimation method>
FIG. 4 is a flowchart showing the procedure of the fatigue level estimation process. Hereinafter, the fatigue level estimation process in the fatigue level estimation system shown in FIG. 1 will be explained with reference to FIGS. 3 and 4.

First, a data acquisition step (S110) is performed. In this step (S110), the data preparation unit 21 acquires data for estimating the degree of fatigue of the rolling component 90 from the rolling component 90 to which repeated loads due to rotation are applied. In this step (S110), data to be used in the step of determining the fatigue level (S120) and subsequent steps for estimating the fatigue level, which will be described later, are prepared. For example, based on data input from the microstructure observation section 23 shown in FIG.

Furthermore, measurement data of X-ray analysis values regarding the rolling component 90 is input to the data preparation section 21 via the input section 17 from the X-ray detector 12 shown in FIG. The measurement data of the X-ray analysis value becomes the second data. Examples of the measurement data of the X-ray analysis values include data regarding residual stress in the fatigue portion of the rolling component 90, and more specifically, measurement data on the depth distribution of residual stress.

Next, a step of determining the level of fatigue (S120) is performed. In this step (S120), the determining unit 31 determines whether or not a tissue change has occurred in the fatigue portion of the rolling component 90 based on the data obtained in the acquiring step (S110).

In the above step (S120), if it is determined that no structural change has occurred, that is, if the determination unit 31 determines that fatigue has not progressed to the third stage in the fatigue part of the rolling component 90, the contact stress is estimated. Step (S131) is performed. In this step (S131), the load estimating unit 32 calculates the contact stress in the fatigue portion of the rolling component 90 based on the measurement data of the depth distribution of residual stress in the fatigue portion of the rolling component 90 included in the second data. presume.

Next, a load estimation step (S132) is performed. In this step (S132), the load estimation unit 32 estimates the load in the fatigue portion of the rolling component 90 based on the measurement data of the depth distribution of residual stress in the fatigue portion of the rolling component 90. In the above steps (S131) and (S132), the load estimation unit 32 may estimate the contact stress and load using the method disclosed in Patent Document 1, for example.

Here, in step (S120), the determining unit 31 determines that no structural change has occurred in the fatigue portion of the rolling component 90 (that is, the fatigue of the rolling component 90 has not progressed to the third stage). ), the residual stress of the rolling component 90 accurately reflects the load conditions acting on the rolling component 90. Therefore, the contact stress and load can be accurately estimated as described above based on the residual stress data.

Next, a 10% lifespan (L ₁₀ ) estimation step (S133) is performed. In this step (S133), the life calculation unit 33 calculates the 10% life (L ₁₀ ) based on the load and the usage conditions of the rolling component 90. The usage conditions of the rolling parts 90 include, for example, the rotational speed of the rolling parts 90, the temperature when the rolling parts 90 are used, the oil type information of the lubricating oil supplied when the rolling parts 90 is used, and the rolling parts. Contains information on the degree of contamination of lubricating oil supplied when using 90. Any method can be used to calculate the 10% life. Further, the lifespan L _n for any probability of failure can be calculated, for example, by multiplying the 10% lifespan (L ₁₀ ) by the reliability coefficient a1. Specifically, the life Ln can be calculated from the 10% life as shown below.

Next, a first fatigue degree calculation step (S134) is performed. In the step (S134), the first fatigue degree calculation unit 34 calculates the first fatigue degree (N/L ₁₀ ) of the rolling component 90 from the number of rotations N of the rolling component 90 and the 10% life (L ₁₀ ). Calculate. Note that the usage time of the rolling component 90 may be used instead of the number of rotations N.

On the other hand, in step (S120), if it is determined that a structural change has occurred, that is, if the determination unit 31 determines that fatigue has progressed to the third stage in the fatigue part of the rolling component 90, X-ray analysis A step (S141) of estimating the first fatigue level using the relationship between the value and the first fatigue level is performed. In the step (S141), the first fatigue degree estimating unit 41 performs an X-ray analysis based on the relationship between the predetermined X-ray analysis value (X-ray stress measurement result) as second data and the first fatigue degree. The first fatigue level (N/L ₁₀ ) is estimated from the value. The above relationship is, for example, the relationship between the fatigue level obtained from a rolling fatigue life test performed on the rolling component 90 and the X-ray stress measurement result of a test piece rolled to that fatigue level. Good too. Data indicating this relationship is stored in the storage unit 61.

Here, since it is determined in step (S120) that a structural change has occurred in the fatigue part of the rolling component 90 (that is, the fatigue of the rolling component 90 has progressed to the third stage), the rolling component 90, it is considered that redistribution of residual stress occurs as the number of rotations increases. Therefore, since there is a correlation between changes in the material structure of the rolling component 90 and the degree of fatigue, as shown in step (S141), based on the relationship between the X-ray analysis value reflecting the structure change and the degree of fatigue By estimating the first fatigue degree, it is possible to more accurately estimate the first fatigue degree.

Next, a diagnostic step (S161) is performed. In this step (S161), the diagnostic unit 70 determines whether the value of the first fatigue degree obtained as described above exceeds a predetermined reference value. If the obtained first fatigue level value exceeds the reference value, a signal indicating that the first fatigue level value has exceeded the reference value is transmitted from the diagnostic unit 70 to the control unit 60. The control unit 60 that has received the signal displays, for example, on the display unit 18 a message indicating that the rolling component 90 needs to be replaced. If the obtained first fatigue level value does not exceed the reference value, a signal indicating that the first fatigue level value does not exceed the reference value is transmitted from the diagnostic unit 70 to the control unit 60. The control unit 60 that has received the signal displays, for example, on the display unit 18 a message indicating that the rolling component 90 does not need to be replaced. Note that depending on the reference value regarding the first fatigue degree described above, a message indicating the time to replace the rolling component 90 may be used as the message displayed on the display unit 18 when the value of the first fatigue degree exceeds the reference value. You can.

<Effect>
A rolling component fatigue level estimation method according to the present disclosure includes a step (step (S110)) of acquiring data for estimating the rolling component fatigue level from rolling components to which repeated loads due to rotation are applied. . The acquiring step (step (S110)) includes the step of acquiring first data regarding the microstructure of the rolling component, and the acquisition of X-ray analysis values regarding the rolling component by irradiating X-rays to fatigued parts of the rolling component. obtaining second data that is measurement data of. The method for estimating the degree of fatigue of rolling parts further includes a step of determining whether or not a structural change has occurred in a fatigued part of the rolling part based on the data obtained in the step of acquiring (step (S110)). Based on the determination result in the determining step (step (S120)) and the data obtained in the acquiring step (step (S110)), internally originating damage of the rolling component is determined. estimating the first degree of fatigue related to (steps (S131) to (S134) and step (S141)). In the step of estimating the first degree of fatigue, if it is determined that no structural change has occurred in the step of determining (step (S120)), the load acting on the rolling component is estimated based on the second data. (step (S132)), a step (step (S133)) of calculating the lifespan based on the load and the usage conditions of the rolling parts, and a step (step (S133)) of calculating the lifespan of the rolling parts based on the number of rotations of the rolling parts and the above-mentioned lifespan. A step (step (S134)) of calculating a degree of fatigue is performed. Further, in the step of estimating the first fatigue degree, if it is determined that a tissue change has occurred in the determining step (step (S120)), the predetermined second data and the first fatigue degree are Based on the relationship, a step (step (S141)) of estimating the first fatigue level from the second data is performed.

In this way, the method for estimating the degree of fatigue of rolling parts described above includes the step (step (S120)) of determining whether or not a structural change has occurred in the fatigued part. Depending on whether or not a structural change has occurred, that is, whether rolling contact fatigue has progressed to the third stage, it is possible to use different methods for estimating the degree of fatigue corresponding to each state. Therefore, the degree of fatigue of rolling parts can be estimated with high accuracy.

In the above method for estimating the fatigue level of rolling parts, the usage conditions of the rolling parts include the rotational speed of the rolling parts 90, the temperature when the rolling parts 90 are used, and the level of lubricating oil supplied when the rolling parts 90 are used. The information may include oil type information and information on the degree of contamination of the lubricating oil supplied when the rolling component 90 is used.

In this case, if no structural change has occurred in the fatigued part of the rolling component 90 (that is, if rolling fatigue has not progressed to the third stage), the 10% life estimation step (step (S133)) The lifespan can be estimated with high precision, and as a result, the lifespan of the rolling component 90 can be calculated with high precision.

In the method for estimating the fatigue level of a rolling component, the second data includes data on six components of residual stress in a fatigued part of the rolling component 90, data on the amount of retained austenite in the fatigued part of the rolling component 90, and data on the amount of retained austenite in the fatigued part of the rolling component 90. Data showing the variation in diffraction intensity with respect to the center angle of the annular diffraction X-ray diffracted at the fatigue part of It may include at least one data selected from the group consisting of data of the difference from the maximum value.

In this case, since the data mentioned above has a strong correlation with the fatigue state of the rolling component 90, the degree of fatigue of the rolling component 90 can be estimated with high accuracy by using the data described above as the second data.

The rolling component fatigue level estimation method may further include a step (step (S161)) of notifying whether or not the rolling component 90 requires replacement or notifying the replacement time based on the first fatigue level. . In this case, maintenance of the rolling component 90 can be appropriately performed based on the accurately estimated first fatigue degree.

The fatigue degree estimation program according to the present disclosure is a fatigue degree estimation program for rolling parts, and includes a step of acquiring data for estimating the fatigue degree from rolling parts to which repeated loads due to rotation are applied to a computer. Step (S110)) is executed. The acquiring step (step (S110)) includes the step of acquiring first data regarding the microstructure of the rolling component, and the acquisition of X-ray analysis values regarding the rolling component by irradiating X-rays to fatigued parts of the rolling component. and obtaining second data that is measurement data. The fatigue level estimation program includes a step (step S110) of determining whether or not a structural change has occurred in a fatigued portion of the rolling component 90 based on the data obtained in the step of acquiring (step (S110)). (S120)), the determination result in the determining step (step (S120)), and the data obtained in the acquiring step (step (S110)), 1. Estimating the degree of fatigue. In the step of estimating the first fatigue degree, if it is determined that no structural change has occurred in the step of determining (step (S120)), the load acting on the rolling component 90 is calculated based on the second data. A step of estimating (step (S132)), a step (step (S133)) of calculating the life based on the load and the usage conditions of the rolling component 90, and a step (step (S133)) of calculating the life of the rolling component based on the number of rotations and the life of the rolling component 90. A step (step (S134)) of calculating a first fatigue level of 90 is performed. In the step of estimating the first fatigue degree, if it is determined that a tissue change has occurred in the determining step (step (S120)), the relationship between the predetermined second data and the first fatigue degree is determined. Based on this, a step (step (S141)) of estimating the first fatigue degree from the second data is performed.

In this way, the program for estimating the degree of fatigue of the rolling component 90 described above causes the computer to execute the step (step (S120)) of determining whether or not a structural change has occurred in the fatigued portion. The first degree of fatigue is estimated by using different estimation methods corresponding to each state, depending on whether or not a structural change has occurred in the fatigued part, that is, whether rolling contact fatigue has progressed to the third stage. can. Therefore, the degree of fatigue of the rolling component 90 can be estimated with high accuracy.

The fatigue level estimation program further causes the computer to execute a step (step (S161)) of notifying whether or not the rolling parts require replacement or notifying the replacement time of the rolling parts based on the first fatigue level. Good too. In this case, information used for maintenance of the rolling component 90 can be notified based on the accurately estimated first fatigue degree.

The rolling component fatigue level estimating device 14 according to the present disclosure includes a determining unit 31, a load estimating unit 32,
It includes a lifespan calculation section 33, a first fatigue degree calculation section 34, and a first fatigue degree estimation section 41. The determining unit 31 receives first data regarding the microstructure of the rolling component 90 and first data that is measured data of X-ray analysis values regarding the rolling component obtained by irradiating the fatigue portion of the rolling component 90 with X-rays. Based on at least one of the two data, it is determined whether or not a structural change has occurred in the fatigue portion of the rolling component 90. The load estimating unit 32 estimates the load acting on the rolling component 90 based on the second data when the determining unit 31 determines that no tissue change has occurred. The lifespan calculation unit 33 calculates the lifespan based on the load and the usage conditions of the rolling component 90. The first fatigue degree calculation unit 34 calculates the first fatigue degree of the rolling component 90 from the number of rotations of the rolling component 90 and the above-mentioned lifespan. When the determining unit 31 determines that a tissue change has occurred, the first fatigue level estimating unit 41 calculates the second data based on the relationship between the predetermined X-ray analysis value and the first fatigue level. A first fatigue level is estimated.

In this way, since the above-described rolling component fatigue level estimating device 14 includes the determination unit 31 that determines whether or not a structural change has occurred in a fatigued portion, it is possible to detect a structural change in a fatigued portion of the rolling component 90. The first fatigue degree can be estimated using a fatigue degree estimation method corresponding to each state, depending on whether or not rolling fatigue has occurred, that is, whether rolling contact fatigue has progressed to the third stage. Therefore, the first fatigue degree of the rolling component 90 can be estimated with high accuracy.

(Embodiment 2)
<Configuration of fatigue level estimation system>
FIG. 5 is a schematic diagram showing the configuration of a fatigue level estimation system according to the second embodiment. Referring to FIG. 5, the fatigue level estimation system basically has the same configuration as the fatigue level estimation system shown in FIG. 1, but the fatigue level estimation system shown in FIG. The estimation system is different.

The surface shape measuring device 13 measures the surface shape of the rolling component 90. As the surface profile measuring device 13, for example, a laser microscope can be used. The surface to be measured may be, for example, a partial surface of a bearing ring of a rolling bearing as the rolling component 90, or the entire surface of a rolling element as the rolling component 90.

The fatigue level estimating device 14 shown in FIG. The degree of fatigue of the rolling component 90 is estimated based on the data of the surface shape of the rolling component 90 measured by the surface shape measuring device 13 described above. The hardware configuration of the fatigue level estimation device 14 shown in FIG. 5 is basically the same as the hardware configuration of the fatigue level estimation device 14 according to the first embodiment shown in FIG. 2.

<Functional configuration of fatigue level estimation device>
FIG. 6 is a diagram showing the functional configuration of the fatigue level estimation device shown in FIG. 5. The fatigue level estimating device 14 shown in FIG. 6 basically has the same functional configuration as the fatigue level estimating device 14 shown in FIG. 3, but in addition to the configuration of the fatigue level estimating device 14 shown in FIG. This differs from the fatigue level estimating device 14 shown in FIG. 3 in that it includes a stress estimating section 51, a life estimating section 53, a second fatigue level estimating section 54, and a fatigue level determining section 55. The control section 60, the data preparation section 21, the judgment section 31, the load estimation section 32, the life calculation section 33, the first fatigue degree calculation section 34, the first fatigue degree estimation section 41, and the diagnosis section 70. , the contact stress estimation section 51, the life estimation section 53, the second fatigue degree estimation section 54, and the fatigue degree determination section 55 are realized by the CPU 15 executing a fatigue degree estimation program stored in the memory 16. Ru.

<Steps for fatigue level estimation method>
FIG. 7 is a flowchart showing the procedure of fatigue level estimation processing. Below, Figures 6 and 7
The fatigue level estimation process in the fatigue level estimation system shown in FIG. 5 will be explained with reference to FIG. The fatigue level estimation process shown in FIG. 7 basically has the same configuration as the fatigue level estimation process shown in FIG. 4, but the types of data acquired in the data acquisition step (S110) have increased. A point that includes steps (S151) to (S154) for estimating a second fatigue degree for surface-originated damage, and a rolling point that is larger of the first fatigue degree and the second fatigue degree. This process differs from the fatigue level estimation process shown in FIG. 4 in that it includes a step (S155) for determining the fatigue level of the component. This will be explained in detail below.

In the data acquisition step (S110), the data preparation unit 21 obtains first data regarding the microstructure in the fatigue portion of the rolling component 90 described in FIG. In addition to the above data, third data regarding the surface shape of the fatigue portion of the rolling component 90 is prepared. The third data is, for example, data on a measured shape of the surface of the rolling component 90 measured by the surface shape measuring device 13. The surface shape data is input to the data preparation section 21 via the input section 17. Further, the second data includes triaxial residual stress data on the surface of the fatigue portion of the rolling component 90 and residual stress depth distribution data based on X-rays.

Next, step (S120) is performed similarly to the fatigue level estimation process shown in FIG. Depending on the determination result of step (S120), steps (S131) to (S134) or step (S141) are performed, similar to the fatigue level estimation process shown in FIG. 4. As a result, a first fatigue degree for internally initiated damage is obtained.

On the other hand, in order to obtain a second degree of fatigue regarding surface-originated damage, a step (S151) of calculating the contact stress of the real contact portion is performed. In step (S151), the contact stress estimation unit 51 calculates the contact stress of the real contact portion based on the second data and the third data. Data such as the rotational speed of the rolling component 90, operating temperature, type of lubricating oil, and weight may be used to calculate the contact stress. Here, when determining the stress of the actual contact portion from surface shape data (for example, surface roughness data), the value of the contact load is required. For the contact load, an estimated load obtained from depth analysis of X-ray stress measurement may be used, or if the working load of the rolling component 90 can be estimated in advance, the value of the working load may be used.

Next, a step (S152) of estimating the repeated stress on the rolling surface is performed. In step (S152), the contact stress estimating unit 51 estimates the contact stress that repeatedly acts on the fatigued part of the rolling component 90 based on the contact stress of the real contact part calculated in the above step (S151).

Next, a step (S153) of estimating the 10% life from the SN diagram is performed. In this step (S153), the life estimating unit 53 estimates the 10% life (L ₁₀ ) using the relationship between the contact stress and the life determined in advance, a so-called SN diagram. The SN diagram is stored in the storage unit 61.

Next, a step (S154) of estimating the degree of surface fatigue (second degree of fatigue) is performed. In this step (S154), the second fatigue degree estimating unit 54 calculates a second fatigue degree (N/L ₁₀ ) of the rolling component 90 from the number of rotations N of the rolling component 90 and the 10% life (L ₁₀ ). Calculate. Note that the usage time of the rolling component 90 may be used instead of the number of rotations N.

Next, a step (S155) is performed in which the larger value of the first fatigue degree and the second fatigue degree is determined as the fatigue degree of the rolling component. In step (S155), the fatigue degree determination unit 55 determines the first fatigue degree regarding internal origin type damage obtained in step (S134) or step (S141) and the first fatigue degree regarding internal origin type damage obtained in step (S154). Among the second fatigue degrees related to damage, the larger value is determined as the fatigue degree of the rolling component 90.

Next, similar to the fatigue level estimation process shown in FIG. 4, a diagnostic step (S161) is performed. In this step (S161), the diagnosis unit 70 determines whether the fatigue level value determined as described above exceeds a predetermined reference value. When the determined fatigue level value exceeds the reference value, a signal indicating that the fatigue level value exceeds the reference value is transmitted from the diagnostic unit 70 to the control unit 60. The control unit 60 that has received the signal displays, for example, on the display unit 18 a message indicating that the rolling component 90 needs to be replaced. If the determined fatigue level value does not exceed the reference value, a signal indicating that the fatigue level value does not exceed the reference value is transmitted from the diagnostic unit 70 to the control unit 60. The control unit 60 that has received the signal displays, for example, on the display unit 18 a message indicating that the rolling component 90 does not need to be replaced.

<Effect>
In the method for estimating the fatigue level of a rolling component, the step of obtaining (step (S110)) may include a step of measuring the fatigue portion of the rolling component 90 to obtain third data regarding the surface shape. The above method for estimating fatigue level of rolling parts includes a step (step ( S151) to (S154) may be provided.The step of estimating the second degree of fatigue is based on the second data and the third data, and the contact stress that is repeatedly acting on the fatigue portion of the rolling component 90 is estimated. (step (S152)), a step (step (S153)) of estimating the life from contact stress based on the predetermined relationship between contact stress and life (SN diagram), and The method may include a step (step (S154)) of estimating a second fatigue degree of the rolling component 90 from the number of rotations and the life of the component 90. The rolling component 90 may have a step (step (S155)) of determining the larger value of the degree and the second degree of fatigue as the degree of fatigue of the rolling component 90.

In this case, the degree of fatigue of the rolling component 90 can be estimated more accurately by considering both the first degree of fatigue regarding internally originating damage and the second degree of fatigue regarding surface originating damage.

The rolling component fatigue level estimation method may further include the step of notifying whether or not the rolling component 90 needs to be replaced or notifying when to replace the rolling component 90 based on the fatigue level. In this case, maintenance of the rolling component 90 can be appropriately performed based on the accurately estimated fatigue level.

In the fatigue degree estimation program, the step of obtaining (step (S110)) may include a step of measuring the fatigue portion of the rolling component 90 to obtain third data regarding the surface shape. The fatigue degree estimation program includes a step (step (S151)) of estimating a second fatigue degree regarding surface-originated damage of the rolling component 90 based on the data obtained in the acquiring step (step (S110)). ) to (S154)) may be executed. The step of estimating the second degree of fatigue includes a step (step (S152)) of estimating the contact stress repeatedly acting on the fatigue portion of the rolling component 90 based on the second data and the third data, and a step (step (S152)) determined in advance. A step (step (S153)) of estimating the lifespan from the contact stress based on the relationship between the contact stress and the lifespan determined, and a second fatigue degree of the rolling part 90 from the number of rotations and the lifespan of the rolling part 90. It may also include a step of estimating (step (S154)). Further, the fatigue degree estimation program may cause the computer to execute a step (step (S155)) of determining the larger value of the first fatigue degree and the second fatigue degree as the fatigue degree of the rolling component. good.

In this case, the degree of fatigue of the rolling component 90 can be estimated more accurately by considering both the first degree of fatigue regarding internally originating damage and the second degree of fatigue regarding surface originating damage.

The fatigue level estimation program may further cause the computer to execute a step (step S161) of notifying whether or not the rolling component 90 requires replacement or notifying the replacement time of the rolling component 90 based on the fatigue level. good. In this case, information used for maintenance of the rolling component 90 can be notified based on the accurately estimated fatigue level.

The rolling component fatigue level estimating device 14 may include a contact stress estimating section 51, a life estimating section 53, a second fatigue level estimating section 54, and a fatigue level determining section 55. The contact stress estimating unit 51 estimates the contact stress repeatedly acting on the fatigue portion of the rolling component 90 based on the second data and third data regarding the surface shape obtained by measuring the fatigue portion of the rolling component 90. Estimate. The life estimating unit 53 estimates the life from the contact stress based on the relationship (SN diagram) between the predetermined contact stress and the life with respect to an arbitrary probability of failure. The second fatigue degree estimation unit 54 estimates the second fatigue degree of the rolling component 90 from the number of rotations and the life of the rolling component 90. The fatigue level determination unit 55 determines the larger value of the first fatigue level and the second fatigue level as the fatigue level of the rolling component 90.

In this case, the degree of fatigue of the rolling component 90 can be estimated more accurately by considering both the first degree of fatigue regarding internally originating damage and the second degree of fatigue regarding surface originating damage.

(Embodiment 3)
<Steps for estimating fatigue level>
FIG. 8 is a flowchart showing the procedure of fatigue level estimation processing. Note that the fatigue level estimation system including the fatigue level estimation device according to the third embodiment, which performs the fatigue level estimation process shown in FIG. 8, is basically the same as the fatigue level estimation system according to the second embodiment. It has the following configuration. Hereinafter, the fatigue level estimation process in the fatigue level estimation system according to the present embodiment will be explained with reference to FIG.

The fatigue degree estimation process shown in FIG. 8 basically has the same configuration as the fatigue degree estimation process shown in FIG. 7, but when it is determined that a tissue change has occurred in step (S120) This process is different from the fatigue level estimation process shown in FIG. That is, in the fatigue degree estimation process shown in FIG. 8, if it is determined in the above step (S120) that a tissue change has occurred, a contact stress estimation step (S171) is performed. In this step (S171), the load estimating unit 32 (see FIG. 6) calculates the depth distribution of the variation in diffraction intensity with respect to the central angle of the annular diffracted X-ray in the fatigue part of the rolling component 90 included in the second data. The contact stress at the fatigue portion of the rolling component 90 is estimated based on the measurement data. For example, the load estimating unit 32 calculates the variation in diffraction intensity based on measured data of depth distribution, which is the distribution data in the depth direction of the variation in diffraction intensity with respect to the center angle of the annular diffraction X-ray, as described later. The first depth at which the value is maximum may be determined. The load estimating unit 32 may use the first depth to estimate the minor axis radius of a contact ellipse that is a contact portion with another member in the fatigue portion.

The above-mentioned depth distribution measurement data may be obtained in step (S110) by measuring the entire annular diffracted X-ray using a two-dimensional detector, or by measuring one part of the annular diffracted X-ray. It may also be obtained by measuring the entire ring-shaped diffracted X-ray by scanning a detector that detects the area. Further, in the above step (S110), the X-rays may be irradiated with the surface of the fatigued portion of the rolling component 90 in a direction perpendicular to the surface or in a direction inclined with respect to the surface.

Next, a load estimation step (S172) is performed. In this step (S172), the load estimating unit 32 estimates the depth distribution of the variation in diffraction intensity with respect to the center angle of the annular diffraction X-ray in the fatigue portion of the rolling component 90. Estimate the load at the fatigue part. In the above steps (S171) and (S172), the load estimating unit 32 uses a different estimation method from the estimation method in steps (S131) and (S132) in FIG. Estimate contact stress and load using methods appropriate to the situation. Note that details will be explained in Examples described later.

Next, a 10% lifespan (L ₁₀ ) estimation step (S173) is performed. In this step (S173), the life calculation unit 33 calculates the 10% life (L ₁₀ ) based on the load and the usage conditions of the rolling component 90. The process in step (S173) is basically the same as the process in step (S133).

Next, a step (S174) of calculating an internal fatigue level (first fatigue level) is performed. In the step (S174), the first fatigue degree calculation unit 34 calculates the first fatigue degree (N/L ₁₀ ) of the rolling component 90 from the number of rotations N of the rolling component 90 and the 10% life (L ₁₀ ). Calculate. Note that the usage time of the rolling component 90 may be used instead of the number of rotations N.

In the fatigue level estimation process shown in FIG. 8, either steps (S131) to (S134) or the above-mentioned steps (S171) to (S174) are performed depending on the determination result in step (S120). As a result, a first fatigue degree for internally originating damage is obtained.

Similarly to the fatigue degree estimation process shown in FIG. 7, the fatigue degree of the rolling component 90 can be estimated by performing steps (S151) to (S155) and step (S161) shown in FIG. and diagnosis based on the degree of fatigue.

<Effect>
A rolling component fatigue level estimation method according to the present disclosure includes a step (step (S110)) of acquiring data for estimating the rolling component fatigue level from rolling components to which repeated loads due to rotation are applied. . The acquiring step (step (S110)) includes the step of acquiring first data regarding the microstructure of the rolling component, and the acquisition of X-ray analysis values regarding the rolling component by irradiating X-rays to fatigued parts of the rolling component. obtaining second data that is measurement data of. The method for estimating the degree of fatigue of rolling parts further includes a step of determining whether or not a structural change has occurred in a fatigued part of the rolling part based on the data obtained in the step of acquiring (step (S110)). Based on the determination result in the determining step (step (S120)) and the data obtained in the acquiring step (step (S110)), The step of estimating the first fatigue level (steps (S131) to (S134) and steps (S171) to (S174)) is provided. The second data includes distribution data in the depth direction of X-ray analysis values regarding the rolling component. In the step of estimating the first degree of fatigue, if it is determined that no structural change has occurred in the step of determining (step (S120)), the load acting on the rolling component is estimated based on the second data. (steps (S131, S132)), a step (step (S133)) of calculating the life of the rolling parts based on the load and the operating conditions of the rolling parts, and a step (step (S133)) of calculating the life of the rolling parts based on the number of rotations and the life of the rolling parts. A step of calculating a first fatigue degree is performed. If it is determined that a tissue change has occurred in the step of determining (step (S120)), the step of estimating the load acting on the rolling component based on the distribution data in the depth direction (step (S171) , S172)), a step (step (S173)) of calculating the lifespan based on the load and the usage conditions of the rolling parts, and calculating a first fatigue degree of the rolling parts from the number of rotations and the lifespan of the rolling parts. The step (step (S174)) is performed.

In this way, the above-described method for estimating the fatigue level of rolling parts, similar to the method for estimating the fatigue level in Embodiment 1 of the present invention, determines whether rolling fatigue has progressed to the third stage or not. Therefore, it is possible to use different methods for estimating the degree of fatigue that correspond to each state. Therefore, the degree of fatigue of rolling parts can be estimated with high accuracy.

In the above method for estimating the fatigue level of rolling parts, the distribution data in the depth direction is data indicating the variation in the diffraction intensity with respect to the center angle of annular diffracted X-rays diffracted at the fatigued part of the rolling part. This is the distribution data. In this case, the above distribution data in the depth direction has a certain relationship with the load that was acting on the rolling parts when the fatigue at the fatigue part entered the third stage, so the distribution data The above load can be estimated based on. As a result, even when fatigue has progressed to the third stage, the first fatigue degree can be calculated based on the load.

Hereinafter, the effects of the above-mentioned method for estimating the degree of fatigue of rolling parts will be explained in more detail. As already mentioned, when fatigue reaches the third stage, a structural change occurs in the fatigued part of the rolling component. In areas where this structural change has occurred, the crystals are oriented in a specific direction. Therefore, variations in diffraction intensity (hereinafter referred to as variations in diffraction intensity) with respect to the central angle of the annular diffracted X-rays increase. The variation in diffraction intensity has a distribution in the depth direction of the rolling contact portion. The inventors have found that the depth at which the peak value of the above-mentioned distribution of variations in diffraction intensity occurs has a corresponding relationship with the minor axis radius of the contact ellipse. Based on this knowledge, contact stress and load can be estimated from the distribution of variations in diffraction intensity, similar to the method of estimating contact stress from residual stress distribution in Non-Patent Document 1. Thereafter, the 10% life can be determined based on the estimated load and bearing usage conditions (for example, rotational speed, usage temperature, lubricating oil type, lubricating oil contamination level). Further, the degree of fatigue can be determined from the ratio of the number of rotations or usage time of the bearing to the above 10% life.

The fatigue degree estimation program according to the present disclosure is a fatigue degree estimation program for rolling parts that is executed in the CPU 15 of the fatigue degree estimation device 14 in the second embodiment of the present invention, and is a program for estimating the fatigue degree of rolling parts that is executed by the CPU 15 of the fatigue degree estimation device 14 according to the second embodiment of the present invention. A step (step (S110)) of acquiring data for estimating the degree of fatigue from the added rolling parts is executed. The acquiring step (step (S110)) includes the step of acquiring first data regarding the microstructure of the rolling component, and the acquisition of X-ray analysis values regarding the rolling component by irradiating X-rays to fatigued parts of the rolling component. and obtaining second data that is measurement data. The fatigue level estimation program includes a step (step S110) of determining whether or not a structural change has occurred in a fatigued portion of the rolling component 90 based on the data obtained in the step of acquiring (step (S110)). (S120)), the determination result in the determining step (step (S120)), and the data obtained in the acquiring step (step (S110)), 1. Estimating the degree of fatigue. The second data includes distribution data of X-ray analysis values regarding the rolling component 90 in the depth direction. In the step of estimating the first degree of fatigue, if it is determined that no structural change has occurred in the step of determining (step (S120)), the load acting on the rolling component is estimated based on the second data. a step (step (S131, S132)) of calculating the life of the rolling component based on the load and the usage conditions of the rolling component (step (S133)); and a step of calculating the life of the rolling component based on the number of rotations and the life of the rolling component 90. A step (step (S134)) of calculating a first fatigue level of 90 is performed. In the step of estimating the first degree of fatigue, if it is determined that a structural change has occurred in the step of determining (step (S120)), the first degree of fatigue is estimated based on the distribution data in the depth direction. A step (step (S171, S172)) of estimating the load that has been applied to the rolling component 90, a step (step (S173)) of calculating the life based on the load and the usage conditions of the rolling component 90, and a step (step (S173)) of estimating the number of rotations of the rolling component A step (step (S174)) of calculating the first fatigue degree of the rolling component 90 from the life span is performed. In this case, the same effects as the fatigue level estimation program in Embodiment 2 of the present invention can be obtained.

The fatigue level estimating device 14 according to the present disclosure includes a determining unit 31, a load estimating unit 32, a life calculating unit 33, and a first fatigue level calculating unit 34. The determining unit 31 is first data regarding the microstructure of the rolling component 90 and measurement data of X-ray analysis values regarding the rolling component 90 obtained by irradiating the fatigue portion of the rolling component 90 with X-rays. Based on at least one of the second data, it is determined whether or not a structural change has occurred in the fatigued portion of the rolling component 90. The load estimation unit 32 estimates the load acting on the rolling component 90 based on the second data. The lifespan calculation unit 33 calculates the lifespan based on the load and the usage conditions of the rolling component 90. The first fatigue degree calculation unit 34 calculates the first fatigue degree of the rolling component 90 from the number of rotations and the life of the rolling component 90. The second data includes distribution data of X-ray analysis values regarding the rolling component 90 in the depth direction. The load estimating unit 32 estimates the load acting on the rolling component 90 based on the second data when the determining unit 31 determines that no tissue change has occurred. The load estimating unit 32 estimates the load acting on the rolling component 90 based on the distribution data in the depth direction when the determining unit 31 determines that a tissue change has occurred. In this case, the same effect as the fatigue level estimation device 14 in the second embodiment of the present invention can be obtained.

A method for estimating contact stress of a rolling component according to the present disclosure is to irradiate X-rays from the surface to the inside of a fatigued part of the rolling component 90, and to A step (step (S110)) of obtaining distribution data of the dispersion of diffraction intensity in the depth direction and estimating the contact stress that repeatedly acts on the fatigued part of the rolling component 90 based on the distribution data in the depth direction. (step (S171)). In this way, the distribution data in the depth direction has a certain relationship with the contact stress acting on the rolling parts when the fatigue in the fatigue part has entered the third stage. , the contact stress can be estimated based on the distribution data.

In the above contact stress estimating method, the step of estimating the contact stress (step (S171)) is to find the first depth at which the value of the dispersion of diffraction intensity is maximum based on the distribution data in the depth direction, and The method may include the steps of estimating the minor axis radius of the contact portion with another member in the fatigue portion using the same depth, and estimating the contact stress based on the minor axis radius.

In the above contact stress estimation method, in the step (step (S110)) of obtaining distribution data in the depth direction, a two-dimensional detector may be used to measure the entire annular diffracted X-ray. In the contact stress estimation method described above, in the step (step (S110)) of obtaining distribution data in the depth direction, a detector that detects a part of the annular diffraction X-rays is scanned, thereby detecting the annular diffraction X-rays. The whole may be measured.

In the above contact stress estimating method, in the step (step (S110)) of obtaining distribution data in the depth direction, X-rays may be irradiated from a direction perpendicular to the surface of the fatigued part of the rolling component 90. In the above contact stress estimating method, in the step (step (S110)) of obtaining distribution data in the depth direction, X-rays may be irradiated from an oblique direction to the surface of the fatigued part of the rolling component 90.

(Example 1)
Fatigue degree estimation according to the present disclosure was performed on the test piece after the life test using a line contact tester. The test conditions are shown in Table 1.

The results are explained below.
<Estimation of fatigue level when fatigue has not progressed to the third stage>
(1) Determining the peak position of residual stress If fatigue has not progressed to the third stage, estimate the contact stress and load from the measurement results of the depth distribution of residual stress. In the example below, the equivalent stress of the residual stress is used, but the load can also be estimated using the residual stress in the circumferential direction and the residual stress in the axial direction.

FIG. 9 is a graph showing the depth distribution of equivalent stress of residual stress. The horizontal axis in FIG. 9 indicates the depth from the surface of the sample, and the unit is μm. The vertical axis of the graph in FIG. 9 indicates the equivalent stress of the residual stress, and the unit is MPa. Note that the test time for the sample from which the data shown in FIG. 9 was obtained using the line contact tester was 148 minutes. As shown in FIG. 9, the residual stress distribution is approximated by a quadratic function. The position where the approximate curve shows a peak is defined as the peak position (depth showing the maximum value) of the equivalent stress Zσeq. In FIG. 9, the peak position Zσeq is 210 μm.

(2) Estimation of contact stress and load It is known that the position where the residual stress is maximum and the position Z ₄₅ where the maximum value of the maximum shear stress τmax occurring inside the rolling element almost coincides (Zσeq≒Z ₄₅ ). . In addition, in the case of line contact, there is a relationship between the minor axis radius b of the contact ellipse and _Z45 as expressed by the following equation (2). Note that in most bearings, the ratio of the long axis to the short axis of the contact ellipse is 10 or more, so there is no problem in using equation (2) regardless of the shape of the rolling elements.

When the two rolling elements in contact are two parallel cylinders, the following equation (3) exists between the short axis radius b and the load P.

Here, l indicates the contact length between the two cylindrical rolling elements 1 and 2. R ₁ and R ₂ indicate the radius of curvature of the rolling elements 1 and 2, respectively. υ ₁ and υ ₂ represent Poisson's ratios of rolling elements 1 and 2, respectively. E ₁ and E ₂ represent the Young's modulus of the rolling elements 1 and 2, respectively.

Here, if the rolling elements 1 and 2 are made of the same material, the above equation (3) can be transformed into the following equation (4).

From the above equations (2) and (4), the following equation (5) is derived.

Therefore, the contact stress P _max is given by the following equation (6).

When the specifications of the test piece shown in Table 2 below and the value of Z ₄₅ determined in the previous section are substituted into the above equation (5), a value of P=18.84 kN is obtained. Moreover, if the above formula (6) is used, a value of contact stress P _max =4.02 GPa can be obtained.

(3) Calculation of fatigue degree Here, it is assumed that contact stress and life have a relationship as shown in equation (7) below.

In past tests conducted by the inventor, data of L ₁₀ =2400 minutes was obtained in the case of a line contact test with P _max =4.2 GPa. Using this data and the relationship of equation (7) above, the estimated life L _10est. and the estimated fatigue degree t/L _10est. are determined. Note that here t indicates the test time. The results were L _10est. = 3452.5 minutes, t/L _10est. = 148/3452.5 = 0.0429.

<Estimation of fatigue level when fatigue progresses to stage 3>
The fatigue level is estimated from the X-ray stress measurement results using a database of the fatigue level obtained from the rolling fatigue life test conducted in advance and the X-ray stress measurement results of test pieces rolled to that fatigue level. . Here, data obtained from a line contact test with P _max =4.2 GPa is used. Note that the number of test pieces in this test was 22.

FIG. 10 is a graph showing the relationship between the variation in diffraction intensity obtained with circumferential incidence and the test time. The horizontal axis of FIG. 10 is the test time, and the unit is minutes. The vertical axis in FIG. 10 indicates variations in diffraction intensity. The measurement depth of the diffraction intensity was 600 μm from the surface of the test piece. The plot in FIG. 10 shows the measured values, and the solid line is the regression curve. Using the regression curve in FIG. 10, for example, when the value of the variation in diffraction intensity is 15,000, it can be estimated that the test time for that test piece is about 1,500 to 2,400 minutes. The broken line in FIG. 10 is the lower limit of the test time estimated from the measured values. By using this broken line, it is possible to estimate the degree of fatigue on the safe side, taking into account the dispersion of data.

Based on FIG. 10, when the fatigue degree t/ _L10 is estimated when the value of the variation in diffraction intensity is 15000, for example, t/L10=1500/2400 to 2400/2400=0.625 to 1.

Next, we will consider the case where retained austenite is used as an index of fatigue level. FIG. 11 is a graph showing the relationship between the reduction rate of retained austenite and test time. The horizontal axis in FIG. 11 indicates the test time, and the unit is minutes. The vertical axis in FIG. 11 shows the reduction rate of retained austenite, and the unit is %. In FIG. 11, data at a depth of 210 μm is shown with a diamond legend, and data at a depth of 600 μm is shown with a square legend. A regression line is shown for each data. Here, the reduction rate of retained austenite was defined as follows.

When using the reduction rate of retained austenite as an index of the degree of _fatigue , as can be seen from FIG. It can be seen that the slope of the diagram is larger when using the test method, and the sensitivity of the reduction rate of retained austenite to the test time is higher. This may be due to the following reasons. That is, when the fatigue enters the third stage, the amount of retained austenite near _Z45 is approximately 0%, and the amount of retained austenite at this depth does not change thereafter. On the other hand, in a region with a depth of 600 μm, the contact stress is smaller than in _Z45 described above, so that the tissue change progresses slowly. Therefore, as shown in FIG. 11, data in a region with a depth of 600 μm has higher sensitivity to the test time.

Using the regression line shown in FIG. 11, for example, when the reduction rate of retained austenite is 30%, it can be estimated that the test time of the test piece is about 1400 to 2400 minutes. Here, the broken line shown in FIG. 11 is the lower limit of the test time estimated from the measured values. By using this broken line, it is possible to estimate the degree of fatigue on the safe side, taking into account the dispersion of data.

Based on FIG. 11, if the fatigue degree t/ _L10 is estimated when the reduction rate of retained austenite is 30%, for example, t/L10=1400/2400 to 2400/2400=0.583 to 1.

As described above, it was found that it may be possible to more accurately evaluate the degree of fatigue by using the measurement values at the depth where fatigue progresses slowly, rather than the measurement values at Z ₄₅ where fatigue progresses quickly. . The same applies to other X-ray analysis values such as half width and residual stress.

(Example 2)
In connection with the fatigue level estimation method according to the third embodiment described above, the following experiment was conducted.

(1) Estimation of contact stress (Pmax) <Preparation of test piece>
X-ray analysis was performed on test pieces subjected to a life test using a line contact fatigue tester or a bearing life tester. Table 3 shows the test conditions for the life test using a line contact fatigue tester, and Table 4 shows the test conditions for the life test using a bearing life tester. Hereinafter, the former test piece will be referred to as a "first test piece", and the latter test piece will be referred to as a "second test piece".

For the X-ray measurement, μ-X360 (manufactured by Pulstech Industries Co., Ltd.), which is a two-dimensional detector type X-ray stress measuring device, was used. Table 5 shows the X-ray measurement conditions.

During X-ray measurement, the coordinate system was defined as shown in FIG. 12. Here, FIG. 12 is a schematic diagram for explaining a coordinate system during X-ray measurement. FIG. 12 shows a case where the outer periphery of the rolling component 90 as a sample is irradiated with X-rays while rotating the rolling component 90 as a sample in the direction shown by an arrow 81. By rotating the rolling component 90, X-rays are irradiated onto the fatigued portion 82 where fatigue has occurred on the outer periphery of the rolling component 90. In the following, the case where the X-ray irradiation direction (ψ, φ ₀ ) shown by the arrow α in FIG.
₀ ) is (30,0) is called circumferential incidence, and the case where the X-ray irradiation direction (ψ, φ ₀ ) is (30,90) is called axial incidence. Further, the diffracted X-rays are generated so as to constitute a conical surface β with the X-ray irradiation part as the apex, as shown in FIG. Here, FIG. 13 is a schematic diagram of diffraction X-rays. As shown in FIG. 13, the diffracted X-rays can be detected by an X-ray detector 12 including a planar detection section. Alternatively, the diffracted X-rays may be detected by scanning the detector 83 that detects a portion of the diffracted X-rays.

When using the X-ray detector 12 (two-dimensional detector) including the planar detection section shown in FIG. 13, annular diffracted X-rays as shown in FIG. 14 are obtained. This is called "circular diffraction X-ray". Here, FIG. 14 is a schematic diagram of the measured annular diffraction X-ray. Further, FIG. 15 is a schematic diagram for explaining variations in diffraction intensity. The horizontal axis of the graph on the left side of FIG. 15 indicates the central angle α of the diffracted X-rays shown in FIG. 14, and the vertical axis indicates the diffraction intensity of the diffracted X-rays. The vertical axis of the graph on the right side of FIG. 15 indicates the diffraction intensity of diffracted X-rays, and the horizontal axis indicates the number of data of the diffraction intensity. The graph on the right side of FIG. 15 shows the frequency distribution of diffraction intensity.

Referring to FIGS. 14 and 15, the parameter "dispersion of diffraction intensity" described later is defined as "standard deviation of diffraction intensity with respect to the central angle α of the annular diffracted X-ray (standard deviation S shown in the graph on the right side of FIG. 15). )”. Note that the above-described variation in diffraction intensity can also be determined using the detector 83, which is a zero-dimensional or one-dimensional detector shown in FIG. 13 and detects a part of the annular diffracted X-ray.

<Measurement results regarding the first test piece of the life test using a line contact fatigue testing machine>
The measurement results regarding the first test piece will be explained with reference to FIGS. 16 and 17. FIG. 16 is a graph showing the depth distribution of circumferential residual stress, which is the result of X-ray measurement of the first test piece. FIG. 17 is a graph showing the depth distribution of variations in diffraction intensity, which is the result of X-ray measurement of the first test piece. Note that for the first test piece from which the measurement results shown in FIGS. 16 and 17 were obtained, the test time of the life test using a line contact type fatigue tester was 1700 minutes. In addition, as a result of performing structural observation on the first test piece after X-ray measurement, it was confirmed that the first test piece had reached the third stage of fatigue.

The horizontal axis in FIGS. 16 and 17 indicates the depth from the surface of the test piece, and the unit is mm. The vertical axis in FIG. 16 indicates the value of circumferential residual stress, and the unit is MPa. The vertical axis in FIG. 17 shows variations in diffraction intensity. From FIG. 16, it can be seen that the depth at which the circumferential residual stress reaches its maximum value is about 0.4 mm, which is a position deeper than _Z45 . Furthermore, from FIG. 17, the dispersion of the diffraction intensity obtained with normal incidence shows the maximum value near Z ₀ , and the dispersion of the diffraction intensity obtained with axial incidence shows the maximum value between Z ₀ and Z ₄₅ . There is. On the other hand, the variation in diffraction intensity obtained when the light is incident in the circumferential direction shows a small change compared to the data on the variation in the diffraction intensity obtained when the light is incident from the other two directions, and does not show a clear maximum value. In addition, when similar measurements were performed on 21 other first test pieces other than the exemplified test pieces, normal incidence and axial incidence were observed near Z ₀ , similar to the first test piece shown in FIG. A distribution with the maximum variation in diffraction intensity was obtained.

<Measurement results regarding the second test piece of the life test using a bearing life tester>
The measurement results regarding the second test piece will be explained with reference to FIGS. 18 and 19. FIG. 18 is a graph showing the depth distribution of circumferential residual stress, which is the result of X-ray measurement of the second test piece. FIG. 19 is a graph showing the depth distribution of variations in diffraction intensity, which is the result of X-ray measurement of the second test piece. Note that for the second test piece for which the measurement results shown in FIGS. 18 and 19 were obtained, the test time of the life test using a bearing life tester was 1196.3 hours. In addition, as a result of performing structural observation on the second test piece after X-ray measurement, it was confirmed that the second test piece had reached the third stage of fatigue.

The vertical and horizontal axes in FIGS. 18 and 19 are the same as the vertical and horizontal axes in FIGS. 16 and 17. From FIG. 18, it can be seen that the depth at which the circumferential residual stress reaches its maximum value is approximately 0.2 mm, which is a position deeper than _Z45 . From FIG. 19, it can be seen that the variation in diffraction intensity has a maximum value near Z ₀ in any incident direction. In addition, when similar measurements were performed on 20 second test pieces other than the exemplified test pieces, the variation in diffraction intensity was maximum near Z ₀ , similar to the second test piece shown in FIG. 19. distribution was obtained.

From the above results, it was found that the dispersion of diffraction intensity has a maximum distribution near _Z0 . As can be seen from FIGS. 17 and 19, the first test piece and the second test piece have similar trends. By utilizing this property, it is possible to estimate the contact stress (Pmax), which is the load on the bearing, even when fatigue has progressed to the third stage. Note that when a change is observed in the dispersion of diffraction intensity, it is determined that the fatigue in the sample has progressed to the third stage.

<Calculation of contact stress (Pmax)>
The calculation formula for calculating the contact stress (Pmax) is shown below. In the case of line contact, there is a relationship between the minor axis radius b of the contact ellipse and Z ₀ as shown in equation (9) below. Note that in most bearings, the ratio of the long axis to the short axis of the contact ellipse is 10 or more, so the following equation (9) can be used regardless of the shape of the rolling elements.

When the two rolling elements 1 and 2 in contact are two parallel cylinders, the following equation (10) exists between the short axis radius b and the load P. Note that the following equation (10) is the same as the equation (3) explained in Example 1.

If the rolling elements 1 and 2 are made of the same material, the above equation (10) can be transformed into the following equation (11).

From the above equations (9) and (11), the following equation (12) is derived.

Therefore, the contact stress P _max is given by the following equation (13).

On the other hand, as described in Example 1, there is a relationship between the minor axis radius b and the load P as expressed by the following equation (14).

From the above equations (11) and (14), the following equation (15) is derived.

Therefore, the contact stress P _max is given by the following equation (16).

As Z ₀ , the depth where the dispersion of diffraction intensity shows the maximum value is used, and as Z ₄₅ , the depth where the residual stress shows the maximum value is used. When fatigue is in the first or second stage, for example in step (S131) in FIGS. 7 and 8, the above equation (16) is used to estimate the contact stress Pmax. On the other hand, when the fatigue is in the third stage, for example in step (S171) in FIG. 8, the above equation (13) is used to estimate the contact stress Pmax. The estimation results of Pmax are shown below.

<Pmax estimation results of the first test piece>
FIG. 20 shows the results of estimating the contact stress Pmax using equation (13) from the measurement results of the first test piece after testing under the conditions shown in Table 6 below.

FIG. 20 is a graph showing the estimation results of the contact stress of the first test piece. The horizontal axis in FIG. 20 indicates the test time for each test piece, and the unit is minutes. The vertical axis of FIG. 20 is the estimated contact stress Pmax (
(estimated surface pressure), and the unit is GPa. The nominal value of the test surface pressure (contact stress) for the first test piece was 4.2 GPa, whereas the estimated average value of Pmax was 4.31 GPa as shown in Figure 20, with a standard deviation of 0. It was .12 GPa.

<Pmax estimation result of second test piece>
FIG. 21 shows the results of estimating the contact stress Pmax using equation (13) from the measurement results of the second test piece after testing under the conditions shown in Table 7 below.

FIG. 21 is a graph showing the estimation results of the contact stress of the second test piece. The horizontal axis in FIG. 21 indicates the test time for each test piece, and the unit is time. The vertical axis in FIG. 21 indicates the estimated contact stress Pmax (estimated surface pressure), and the unit is GPa. The nominal value of the test surface pressure (contact stress) for the second specimen was 3.2 GPa, whereas the average value of estimated P _max was 3.44 GPa, as shown in Figure 21, and the standard deviation was It was 0.27 GPa.

<Calculation of fatigue level>
The degree of fatigue is calculated based on the contact stress regarding the first test piece and the second test piece estimated in the previous section. It is assumed that contact stress and life have a relationship expressed by the following equation (17).

In past tests conducted by the inventor, data of L ₁₀ =2400 minutes was obtained in the case of a life test using a line contact fatigue testing machine with P _max =4.2 GPa. Furthermore, in the case of a life test using a bearing life tester with P _max =3.2 GPa, data of L ₁₀ =1622 hours was obtained. Using these data and the relationship of equation (17) above, the estimated life L _10est. and estimated fatigue degree t/L _10est. are determined for each sample. Note that here t indicates the test time. The results are shown in Tables 6 and 7. As described above, the degree of fatigue can be calculated using the contact stress Pmax estimated from the variation in diffraction intensity.

The embodiments and examples disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

11 irradiation section, 12 X-ray detector, 12A detection section, 12B hole, 13 surface profile measuring device, 14 fatigue level estimation device, 16 memory, 17 input section, 18 display section, 21 data preparation section, 23 microstructure observation section , 31 judgment section, 32 load estimation section, 33 life calculation section, 34 first fatigue degree calculation section, 41 first fatigue degree estimation section, 51 contact stress estimation section, 53 life estimation section, 54 second fatigue degree estimation section, 55 Fatigue level determining section, 60 Control section, 61 Storage section, 70 Diagnosis section, 81 Arrow, 82 Fatigue section, 83 Detector, 90 Rolling parts.

Claims (22)

comprising the step of acquiring data for estimating the degree of fatigue of the rolling parts from the rolling parts to which repeated loads are applied due to rotation;
The obtaining step includes:
obtaining first data regarding the microstructure of the rolling component;
obtaining second data that is measurement data of X-ray analysis values regarding the rolling component by irradiating the fatigue portion of the rolling component with X-rays;
a step of determining whether or not a structural change has occurred in the fatigue portion of the rolling component based on the data obtained in the acquiring step;
estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result in the determining step and the data obtained in the acquiring step;
In the step of estimating the first fatigue level,
In the step of determining, if it is determined that the tissue change has not occurred, estimating the load acting on the rolling component based on the second data, and calculating the difference between the load and the rolling component. and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifetime,
In the determining step, when it is determined that the tissue change has occurred, the first fatigue degree is calculated from the second data based on the predetermined relationship between the second data and the first fatigue degree. A method for estimating fatigue level of rolling parts, the method comprising: estimating fatigue level of rolling parts. The second data includes data on the residual stress of six components in the fatigue part of the rolling part, data on the amount of retained austenite in the fatigue part of the rolling part, and data on the amount of residual austenite in the fatigue part of the rolling part. Data showing the variation in diffraction intensity with respect to the central angle of the annular diffraction The method for estimating fatigue level of rolling parts according to claim 1, comprising at least one data selected from the group consisting of difference data. comprising the step of acquiring data for estimating the degree of fatigue of the rolling parts from the rolling parts to which repeated loads are applied due to rotation;
The obtaining step includes:
obtaining first data regarding the microstructure of the rolling component;
obtaining second data that is measurement data of X-ray analysis values regarding the rolling component by irradiating the fatigue portion of the rolling component with X-rays;
a step of determining whether or not a structural change has occurred in the fatigue portion of the rolling component based on the data obtained in the acquiring step;
estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result in the determining step and the data obtained in the acquiring step;
The second data includes distribution data in the depth direction of the X-ray analysis values regarding the rolling component,
In the step of estimating the first fatigue level,
In the step of determining, if it is determined that the tissue change has not occurred, estimating the load acting on the rolling component based on the second data, and calculating the difference between the load and the rolling component. and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifetime,
In the determining step, when it is determined that the tissue change has occurred, a step of estimating the load acting on the rolling component based on the distribution data in the depth direction; A rolling component comprising: calculating a lifespan based on usage conditions of the rolling component; and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifespan. A method for estimating the fatigue level of parts. The distribution data in the depth direction is distribution data in the depth direction of data indicating variations in diffraction intensity with respect to the center angle of annular diffracted X-rays diffracted at the fatigue portion of the rolling component. The method for estimating the fatigue level of rolling parts according to item 3. The usage conditions of the rolling parts include the rotational speed of the rolling parts, the temperature when the rolling parts are used, oil type information of lubricating oil supplied when the rolling parts are used, and the rolling parts. The method for estimating the degree of fatigue of a rolling component according to any one of claims 1 to 4, comprising information on the degree of contamination of the lubricating oil supplied during use. The rolling component according to any one of claims 1 to 5, further comprising the step of notifying whether or not the rolling component requires replacement or notifying a replacement time based on the first fatigue degree. Fatigue level estimation method. The obtaining step includes measuring the fatigue portion of the rolling component to obtain third data regarding the surface shape,
a step of estimating a second degree of fatigue regarding surface-originated damage of the rolling component based on the data obtained in the obtaining step;
The step of estimating the second fatigue level includes:
estimating contact stress repeatedly acting on the fatigue portion of the rolling component based on the second data and the third data;
estimating the life from the contact stress based on a predetermined relationship between the contact stress and the life;
estimating the second degree of fatigue of the rolling component from the number of rotations and the life of the rolling component, further comprising:
The rolling element according to any one of claims 1 to 5, comprising the step of determining the larger of the first fatigue degree and the second fatigue degree as the fatigue degree of the rolling component. A method for estimating the fatigue level of parts. 8. The method for estimating the degree of fatigue of a rolling component according to claim 7, further comprising the step of notifying whether or not the rolling component needs to be replaced or notifying the time to replace the rolling component based on the degree of fatigue. A fatigue degree estimation program for rolling parts,
to the computer,
executing a step of acquiring data for estimating the degree of fatigue from rolling parts subjected to repeated loads due to rotation;
The obtaining step includes:
obtaining first data regarding the microstructure of the rolling component;
obtaining second data that is measurement data of X-ray analysis values regarding the rolling component by irradiating the fatigue portion of the rolling component with X-rays;
to the computer;
a step of determining whether or not a structural change has occurred in the fatigue portion of the rolling component based on the data obtained in the acquiring step;
estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result in the determining step and the data obtained in the acquiring step;
In the step of estimating the first fatigue level,
In the step of determining, if it is determined that the tissue change has not occurred, estimating the load acting on the rolling component based on the second data, and calculating the difference between the load and the rolling component. and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifetime,
In the determining step, when it is determined that the tissue change has occurred, the first fatigue degree is calculated from the second data based on the predetermined relationship between the second data and the first fatigue degree. A program for estimating the degree of fatigue of rolling parts, in which the step of estimating the fatigue level of rolling parts is performed. A fatigue degree estimation program for rolling parts,
to the computer,
executing a step of acquiring data for estimating the degree of fatigue from rolling parts subjected to repeated loads due to rotation;
The obtaining step includes:
obtaining first data regarding the microstructure of the rolling component;
obtaining second data that is measurement data of X-ray analysis values regarding the rolling component by irradiating the fatigue portion of the rolling component with X-rays;
to the computer;
a step of determining whether or not a structural change has occurred in the fatigue portion of the rolling component based on the data obtained in the acquiring step;
estimating a first degree of fatigue regarding internally originating damage of the rolling component based on the determination result in the determining step and the data obtained in the acquiring step;
The second data includes distribution data in the depth direction of the X-ray analysis values regarding the rolling component,
In the step of estimating the first fatigue level,
In the step of determining, if it is determined that the tissue change has not occurred, estimating the load acting on the rolling component based on the second data, and calculating the difference between the load and the rolling component. and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifetime,
In the determining step, when it is determined that the tissue change has occurred, a step of estimating the load acting on the rolling component based on the distribution data in the depth direction; A rolling component comprising: calculating a lifespan based on usage conditions of the rolling component; and calculating the first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifespan. Part fatigue estimation program. to the computer;
The rolling component according to claim 9 or 10, further comprising a step of notifying whether or not the rolling component needs to be replaced or notifying a replacement time of the rolling component based on the first fatigue degree. A fatigue level estimation program. The obtaining step includes measuring the fatigue portion of the rolling component to obtain third data regarding the surface shape,
to the computer;
performing a step of estimating a second fatigue degree regarding surface-originated damage of the rolling component based on the data obtained in the obtaining step;
The step of estimating the second fatigue level includes:
estimating contact stress repeatedly acting on the fatigue portion of the rolling component based on the second data and the third data;
estimating the life from the contact stress based on a predetermined relationship between the contact stress and the life;
estimating the second degree of fatigue of the rolling component from the number of rotations and the life of the rolling component, further comprising:
to the computer;
The degree of fatigue of a rolling component according to claim 9 or 10, wherein the step of determining a larger value of the first degree of fatigue and the second degree of fatigue as the degree of fatigue of the rolling component is executed. Estimation program. to the computer;
13. The rolling component fatigue level estimation program according to claim 12, further comprising the step of notifying whether or not the rolling component requires replacement or notifying the replacement timing of the rolling component based on the fatigue level. at least first data regarding the microstructure of the rolling component and second data that is measurement data of an X-ray analysis value regarding the rolling component obtained by irradiating a fatigued part of the rolling component with X-rays. a determination unit that determines whether or not a structural change has occurred in the fatigue portion of the rolling component based on either one;
a load estimating unit that estimates a load acting on the rolling component based on the second data when the determining unit determines that the tissue change has not occurred;
a lifespan calculation unit that calculates the lifespan based on the load and the usage conditions of the rolling component;
a first fatigue degree calculation unit that calculates a first fatigue degree of the rolling component from the number of rotations of the rolling component and the lifespan;
When the determination unit determines that the tissue change has occurred, the first fatigue degree is determined from the second data based on the relationship between the predetermined X-ray analysis value and the first fatigue degree. A fatigue degree estimating device for rolling parts, comprising: a first fatigue degree estimating section that estimates the fatigue degree of a rolling component. at least first data regarding the microstructure of the rolling component and second data that is measurement data of an X-ray analysis value regarding the rolling component obtained by irradiating a fatigued part of the rolling component with X-rays. a determination unit that determines whether or not a structural change has occurred in the fatigue portion of the rolling component based on either one;
a load estimation unit that estimates a load acting on the rolling component based on the second data;
a lifespan calculation unit that calculates the lifespan based on the load and the usage conditions of the rolling component;
a first fatigue degree calculation unit that calculates a first fatigue degree of the rolling component from the number of rotations and the life of the rolling component;
The second data includes distribution data in the depth direction of the X-ray analysis values regarding the rolling component,
The load estimating unit is
In the judgment unit, when it is judged that the tissue change has not occurred, estimating the load acting on the rolling component based on the second data,
Fatigue degree estimation of rolling parts, estimating the load acting on the rolling parts based on the distribution data in the depth direction when the judgment unit determines that the structural change has occurred. Device. Contact for estimating contact stress repeatedly acting on the fatigue portion of the rolling component based on the second data and third data regarding the surface shape obtained by measuring the fatigue portion of the rolling component. A stress estimator,
a life estimating unit that estimates the life from the contact stress based on a predetermined relationship between the contact stress and the life;
a second fatigue degree estimation unit that estimates a second fatigue degree of the rolling component from the number of rotations and the life of the rolling component;
The rolling component according to claim 14 or 15, further comprising a fatigue level determining unit that determines the larger of the first fatigue level and the second fatigue level as the fatigue level of the rolling component. Fatigue level estimation device. Obtaining distribution data in the depth direction of variations in diffraction intensity with respect to a central angle of annular diffracted X-rays diffracted at the fatigued part by irradiating X-rays from the surface to the inside of the fatigued part of the rolling component. and,
A method for estimating contact stress of a rolling component, comprising the step of estimating a contact stress that repeatedly acts on the fatigue portion of the rolling component based on the distribution data in the depth direction. The step of estimating the contact stress includes:
Based on the distribution data in the depth direction, a first depth at which the value of the dispersion of the diffraction intensity is maximum is determined, and using the first depth, the shortness of the contact part with another member in the fatigue part is determined. estimating the shaft radius;
The method for estimating contact stress of a rolling component according to claim 17, comprising the step of estimating contact stress based on the minor axis radius. The contact stress estimation method for a rolling component according to claim 17 or 18, wherein in the step of obtaining the distribution data in the depth direction, the entire annular diffraction X-ray is measured using a two-dimensional detector. . In the step of obtaining the distribution data in the depth direction, the entire annular diffracted X-ray is measured by scanning a detector that detects a part of the annular diffracted X-ray. 19. The method for estimating contact stress of rolling parts according to item 18. According to any one of claims 17 to 20, in the step of obtaining distribution data in the depth direction, the X-rays are irradiated from a direction perpendicular to the surface of the fatigue portion of the rolling component. The described contact stress estimation method for rolling parts. Any one of claims 17 to 20, wherein in the step of obtaining distribution data in the depth direction, the X-rays are irradiated from a direction oblique to the surface of the fatigue portion of the rolling component. Contact stress estimation method for rolling parts described in .

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