JP7247074B2 - LASER PEENING APPARATUS, METHOD AND PROGRAM - Google Patents

Description

An embodiment of the present invention relates to a laser peening technique for improving performance by irradiating a surface of an object to be treated with a laser beam.

The surface of the material tends to be a starting point for fatigue fracture, stress corrosion cracking, and the like. Therefore, by applying compressive residual stress to the vicinity of the surface of the material to suppress crack initiation and propagation, it is possible to improve fatigue fracture resistance and stress corrosion cracking resistance of the material.

Laser peening is a technique that imparts compressive residual stress to the surface of the object to be processed. A plasma is generated and expanded by irradiating the object with a pulsed laser. Due to the mechanical reaction of this expansion, the vicinity of the surface of the construction target is compressed, and stress remains. In laser peening, the magnitude of residual stress and the depth to which it is applied can be controlled by adjusting the working conditions such as the energy of the laser beam and the irradiation area.

Japanese Patent No. 5375476

It is not easy to obtain the desired residual stress by laser peening. First, the appropriate working conditions for laser peening are know-how, and often have to be set based on experience. Furthermore, depending on (the shape of) the object to be worked on and the surrounding environment, the energy of the laser beam irradiated to the working part and the irradiation area may become unstable. In this case, the desired residual stress may not be obtained by construction.

Confirmation that the desired residual stress is imparted to the construction part and that the construction quality is ensured is made by measuring the residual stress after construction, for example, by an X-ray stress measurement method or a perforation method combined with sequential polishing. However, there are cases where it is difficult to measure residual stress after construction, such as in actual products and narrow spaces.

The embodiments of the present invention have been made in consideration of such circumstances, and it is an object of the present invention to provide a laser peening technique capable of confirming quality assurance without actually measuring residual stress after construction.

In the laser peening apparatus according to the embodiment, an image acquisition unit that acquires a photographed image of an irradiation mark formed on an irradiation surface when peening a target to be processed by irradiating a pulse laser, and a photographed image of the irradiation mark from the photographed image. a measurement unit for measuring shape data, wherein the captured image is captured from an oblique direction with respect to the irradiation axis of the pulsed laser, or is formed by the pulsed laser that is intermittently irradiated. a first calculator that calculates a first deviation between the shape data of the plurality of irradiation marks and a first reference value; and a first determination unit that determines whether the first deviation is less than a first threshold. Alternatively, a database representing the relationship between the shape data of the irradiation mark and the residual stress imparted to the construction object, and the residual stress is estimated based on the shape data of the irradiation mark measured from the photographed image and the database. and an estimating unit .

According to the embodiment of the present invention, a laser peening technique is provided that enables confirmation of quality assurance without actually measuring residual stress after construction.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the laser peening apparatus which concerns on 1st Embodiment of this invention. The block diagram of the modification of the laser peening apparatus which concerns on 1st Embodiment. (A) A photographed image of an irradiation mark by an optical camera, (B) A photographed image of the same irradiation mark by a laser scanning camera. The enlarged view of the longitudinal section of a laser spot. (A) and (B) are graphs showing irradiation mark depths with respect to laser spot positions. 4 is a flow chart of a laser peening method and a laser peening program according to the first embodiment; The partial block diagram of the laser peening apparatus which concerns on 2nd Embodiment. FIG. 10 is a graph showing the relationship between the irradiation mark depth D and the laser intensity Φ when laser peening is performed on an alloy 600 object. 4 is a graph showing the relationship between impact pressure P and laser intensity Φ when laser peening is performed on a SUS316L object. (A) and (B) Graphs showing residual stress versus laser spot position. Flowcharts of a laser peening construction method and a laser peening construction program according to a second embodiment.

(First embodiment)
An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a laser peening apparatus 10A according to the first embodiment of the present invention. As shown in FIG. 1, the laser peening apparatus 10A (10) comprises a laser irradiation section 20, a monitoring section 30A (30), a driving section 23, a laser scanning section 18, a camera 11 and a display section 12. Among them, the laser irradiation unit 20 includes a laser oscillator 21 and a condensing optical system 22 .

A laser oscillator 21 oscillates a pulse laser 16 for laser peening. The wavelength and pulse width of this pulse laser 16 can be selected as appropriate. For example, a Nd:YAG laser can be used to generate a pulse laser with a wavelength of 1064 nm or 532 nm and a pulse width of several nanoseconds to several tens of nanoseconds. Irradiation conditions such as the output intensity of the pulse laser 16 oscillated by the laser oscillator 21 are adjusted by the drive unit 23 .

The condensing optical system 22 irradiates the pulse laser 16 oscillated by the laser oscillator 21 to the object 17 to be worked in a spot shape. The condensing optical system 22 includes mirrors 25 and 26 that reflect the pulse laser 16 output from the laser oscillator 21 in the direction of 45°, a converging lens 27 that converges the pulse laser 16, and the converging lens 27 on the object 17 to be worked. and a lens displacement unit 28 that changes the size of the laser spot 19 by relatively displacing it. The size (irradiation area) of the laser spot 19 is changed by adjusting the distance between the converging lens 27 and the object 17 to be processed by the lens displacement section 28 .

The laser scanning unit 18 is a drive mechanism that relatively moves the laser irradiation unit 20 and the construction target 17 in a direction intersecting the irradiation axis 13 . The relative movement between the laser irradiating unit 20 and the object 17 to be worked may be the case where the object 17 to be worked is fixed and the object 17 to be worked is moved, or the object 17 to be worked is moved while the laser irradiating unit 20 is fixed. The shot interval when the laser spot 19 scans (scans) the object 17 to be worked is determined from the frequency and scanning speed of the laser oscillator 21 .

The camera 11 captures a captured image 41 of the irradiation mark 14 formed by irradiating the pulse laser 16 . In FIG. 1 , the camera 11 captures a captured image 41 from an oblique direction with respect to the irradiation axis 13 of the pulse laser 16 . Note that the arrangement of the camera 11 is not particularly limited, and as shown in FIG. good too. In addition, when the construction target 17 exists in a narrow space or the like and it is difficult for the operator to directly observe it, the camera 11 is provided with a small mirror, a fiberscope, or the like, and the irradiation mark 14 can be photographed through these.

The monitoring unit 30A has an image acquiring unit 31 that acquires a photographed image 41 (FIG. 3) of the irradiation mark 14 (FIG. 4) formed on the irradiated surface 15 when the object 17 to be worked is peened by irradiating the pulse laser 16. , and a measuring unit 32 for measuring the shape data 38 of the irradiation mark 14 from the photographed image 41 . The captured image 41 and the shape data 38 of the irradiation mark 14 can be displayed on the display unit 12 .

FIG. 3A is an image of an irradiation mark taken by the optical camera 11, and FIG. 3B is an image of the same irradiation mark taken by the laser scanning camera 11. FIG. For this camera 11, for example, a CCD camera, a laser, or a 3D scanner utilizing optical interference can be used. For photographing the shape of the irradiation marks 14, it is preferable to photograph light in a wavelength band that does not include the wavelength of the pulse laser 16. FIG. For this purpose, the camera 11 can be equipped with a filter that blocks light at the wavelength of the pulsed laser 16 .

FIG. 4 is an enlarged view of a longitudinal section of the laser spot 19. FIG. A pulsed laser 16 having a pulse width of about 5 to 10 nsec is condensed into a spot 19 having a diameter 2a of about 1 mm and irradiated onto an irradiation surface 15 of a work object 17 . Then, the surface of this construction target 17 absorbs energy and generates plasma. When this plasma is surrounded by a liquid (not shown) transparent to the pulse laser 16 , such as water, the expansion of the plasma is hindered and the internal pressure reaches several GPa, and the object 17 is impacted. Add. At that time, a strong shock wave is generated, which plastically deforms the work object 17 while propagating inside, and compressive residual stress is applied.

Furthermore, irradiation traces 14 are formed on the laser-ablated portions of the irradiation surface 15 of the object 17 after the metal atoms become plasma and evaporate. The measurement unit 32 performs image processing on the captured image ( FIG. 3 ) and measures the depth D of the irradiation mark 14 and the size (radius a or area) of the opening as shape data 38 .

When the same irradiation mark 14 is irradiated with the pulse laser 16 a plurality of times, the measured irradiation mark depth is divided by the number of times of irradiation, and the irradiation mark depth D per one pulse irradiation is calculated. It is preferable to adopt Furthermore, regarding the size (radius a) of the opening of the irradiation mark 14, when laser irradiation is performed while covering a part of the irradiation mark 14, the shape of the irradiation mark 14 is approximated by a circle or an ellipse, and the size of the opening of the irradiation mark is determined. It is desirable to determine the depth (radius a). For the depth D of the irradiation mark and the size of the aperture, an average value or a median value obtained from a plurality of measured values may be used.

The photographed image 41 and the shape data 38 are sequentially stored in a storage unit (not shown) each time the pulse laser 16 intermittently scans and irradiates. The photographed image 41 and the shape data 38 stored in the data memory in this storage section are used for calculation in the calculation section 33 (33a, 33b) and the determination section 34 (34a, 34b), which will be described later.

The first calculator 33a calculates a first deviation 39a (39) between the shape data 38 of the plurality of irradiation marks 14 formed by the intermittently irradiated pulse laser 16 and the first reference value 36a (36). It is. Here, the first reference value 36a is a set value set in advance, shape data 38 of the irradiation mark 14 formed immediately after the start of laser peening, or shape data 38 of the irradiation mark 14 immediately before. Alternatively, it may be an average value or a median value obtained from a plurality of shape data 38 .

The first determination section 34a determines whether or not the first deviation 39a output from the first calculation section 33a is less than the first threshold value 37a. The threshold value 37 is a set value set in advance, and when the deviation 39 does not exceed the threshold value 37, it indicates that the laser peening is progressing normally. If the deviation 39 exceeds the threshold 37, it indicates that the laser peening process is abnormal or unstable. In this case, an operator is warned or an interlock is activated to stop the process. .

FIGS. 5A and 5B are graphs showing the irradiation mark depth D with respect to the position of the laser spot 19. FIG. This graph represents temporal changes in the depth D of the irradiation mark. This graph is displayed on the display unit 12 during or after laser peening. Here, FIG. 5A shows that laser peening is progressing normally when the reference value 36 is 0.5 μm. On the other hand, FIG. 5B shows that the laser peening progress is abnormal.

Note that the residual stress in the vicinity of the surface of the object 17 to be processed caused by laser peening has a correlation with the shape data 38 (in particular, the depth D) of the irradiation marks 14, as will be described later. Therefore, by tracing the photographed image 41 and the shape data 38 of the irradiation mark 14 under construction, it is possible to determine whether the laser peening construction is appropriate. By displaying the shape data 38 over time in a graph or the like, the operator can easily judge the soundness of construction.

The photographed images 41 of the irradiation marks 14 corresponding to the data of the respective irradiation mark depths D can be displayed in parallel on the display unit 12 . Thereby, the operator can evaluate the shape change of the irradiation mark 14 formed intermittently during or after the construction. In addition, it is preferable that the judgment is not performed until several pulses of the laser are irradiated after the start of laser peening. This is because the irradiation mark 14 immediately after the start of operation may have some instability.

When the operator confirms the shot image 41 of the photographed irradiation marks 14 in real time during construction, it is difficult for the operator to visually recognize all the irradiation marks 14 with the naked eye. However, if the shape of the irradiation mark 14 continues to change unstably due to inappropriate construction, the operator will notice the abnormality and recognize that the construction is inappropriate.

Here, as the shape data 38 of the irradiation mark 14, the irradiation mark depth D is used as the determination target, but the size of the opening (radius, area) or both may be used as the determination target. Either the absolute value of the deviation 39 is taken to determine the threshold value 37, or the threshold value 37 is determined by taking into account the plus or minus sign attached to the deviation 39, or the threshold value 37 has either an upper limit or a lower limit. Or setting both (range) is arbitrary.

Further, an adjustment unit 35 is provided in the monitoring unit 30A, and the irradiation conditions of the pulse laser 16 can be adjusted by the driving unit 23 so that the deviation 39 becomes small. When the depth D of the irradiation mark is observed to be small, a command is given to the drive unit 23 so that the laser intensity (W/mm ² ) at the spot 19 is increased. Specifically, the laser oscillator 21 is adjusted to increase the energy of the pulse laser 16, the lens displacement unit 28 is displaced to further converge the laser spot 19, or the scanning speed of the laser scanning unit 18 is reduced to reduce the unit One possibility is to increase the number of laser spots 19 per area.

By providing the adjustment unit 35 in this way, even if the shape data 38 of the irradiation mark 14 changes during construction, the construction conditions of the driving unit 23 can be changed in real time. As a result, the shape data 38 of the irradiation mark 14 can always be kept at the reference value 36 during construction, and the quality of laser peening construction can be improved. If the shape of the irradiation mark 14 does not return to the reference value 36 even if the irradiation conditions are changed (for example, if the conditions are changed a predetermined number of times, or if the conditions cannot be changed due to hardware restrictions, etc.) case), the interlock may be activated to stop construction.

In addition, it is possible to automatically redo the construction for the construction portion in which the shape of the irradiation mark 14 is out of the standard. Alternatively, a permissible value may be set for the number of times the shape of the irradiation mark 14 deviates from the standard, and construction may be continued if the permissible value is not exceeded. As the allowable value, for example, the upper limit of the number of times the shape of the irradiation mark 14 continuously deviates from the standard, or the upper limit of the number of times the shape of the irradiation mark 14 deviates from the standard in the number of times of irradiation with a certain pulse laser, etc. can be used. can.

A laser peening method and a laser peening program according to the first embodiment will be described with reference to the flowchart of FIG. 6 (see FIGS. 1 and 2 as needed). First, at the start of laser peening, the initial irradiation conditions of the pulse laser 16 are determined (S11).

A photographed image 41 of the irradiation mark 14 formed on the irradiated surface 15 when the object 17 to be worked is peened by irradiating the pulse laser 16 is acquired (S12). The photographed image 41 may be photographed from a direction oblique to the irradiation axis 13 of the pulse laser 16 (FIG. 1), or may be photographed from a direction substantially coinciding with the irradiation axis 13 via the half mirror 26 (FIG. 2). can do.

The shape data 38 of the irradiation mark 14 is measured from the photographed image 41 (S13). The photographed image 41 and the shape data 38 of the irradiation marks 14 can be arbitrarily displayed on the display unit 12 . A first deviation 39a between the shape data 38 of the plurality of irradiation marks 14 formed by the pulse laser 16 intermittently irradiated and the first reference value 36a is calculated (S14). The first reference value 36a may be a predetermined set value, stored shape data 38 of the irradiation mark 14 formed in the past, or an average value or median value of a plurality of stored shape data 38. can do.

It is determined whether or not the first deviation 39a is less than the first threshold value 37a (S15). If it is determined to be less than (S15 Yes), the irradiation conditions of the pulse laser 16 are adjusted so that the first deviation 39a becomes smaller (S16), and the next laser spot 19 is irradiated with the pulse laser 16 (S17 No), the process returns to (S12) and this cycle is repeated. Then, when the peening construction to the construction target 17 is completed (S17 Yes), a series of the flow ends (END).

On the other hand, when it is determined that the first deviation 39a exceeds the first threshold value 37a (S15No), a warning is displayed to make the operator aware of it, and then the flow is continued (S18a, S16) or the interlock is activated. It is activated to forcibly terminate the peening operation (S18b, END).

Note that the step of adjusting the irradiation conditions of the pulse laser 16 (S16) is optional and may be omitted. In the above description of the flow, the shape data 38 was sequentially determined each time the irradiation mark 14 was formed by peening. Data 38 may be collectively determined.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 7 to 11. FIG. FIG. 7 is a partial configuration diagram of a laser peening apparatus 10C according to the second embodiment. Although partially omitted from the drawing, the laser peening apparatus 10C of the second embodiment has the same configuration as that of the first embodiment shown in FIG. , a driving unit (not shown), a laser scanning unit 18, a camera 11, and a display unit 12. FIG. In the following, in FIG. 7, parts having configurations or functions common to those in FIG. 1 are denoted by the same reference numerals, and redundant explanations are omitted.

As shown in FIG. 7, the monitoring unit 30B of the laser peening apparatus includes an image acquisition unit 31 that acquires a photographed image 41 (FIG. 3) of the irradiation mark 14 (FIG. 4), and shape data of the irradiation mark 14 from the photographed image 41. 38, a database 42 representing the relationship between the shape data 38 of the irradiation mark 14 and the residual stress 46 imparted to the construction target 17, and the shape data 38 of the irradiation mark measured from the photographed image 41 and the database. and an estimation unit 45 for estimating the residual stress 46 based on 42 . The photographed image 41 of the irradiation mark 14 and the residual stress 46 can be displayed on the display unit 12 .

The second calculator 33b calculates a second deviation 39b (39) between the residual stress 46 estimated by the estimator 45 and the second reference value 36b (36). Here, the second reference value 36a is a preset value, the residual stress 46 of the irradiation marks 14 formed immediately after the start of laser peening, or the residual stress 46 of the irradiation marks 14 immediately before. Alternatively, it may be an average or median value obtained from a plurality of residual stresses 46 . The second determination section 34b determines whether or not the second deviation 39b output from the second calculation section 33b is less than the second threshold value 37b.

The database 42 clarifies the relationship between the shape data 38 of the irradiation mark 14 and the residual stress 46 applied to the object 17 made of various materials through experiments or simulations, and stores the relationship in a storage unit (not shown). . When the shape data 38 are input to the estimator 45, the corresponding residual stress 46 is uniquely estimated based on the database 42. FIG.

FIG. 8 is a graph showing the relationship between the irradiation mark depth D and the laser intensity Φ when laser peening is performed on the object 17 to which Alloy 600 is applied. Thus, it can be seen that there is a one-to-one relationship between the irradiation mark depth D and the laser intensity Φ. That is, the laser intensity Φ of the pulse laser 16 can be obtained from the irradiation mark depth D in the shape data 38 measured by the measuring unit 32 .

Furthermore, FIG. 9 is a graph showing the relationship between the impact pressure P and the laser intensity Φ when laser peening is performed on the object 17 of SUS316L. As shown in equation (1) in FIG. 9, the impact pressure P is proportional to the power of 1/2 of the laser intensity Φ, and the magnitude of the impact pressure P applied to the object 17 irradiated with one pulse of the pulse laser 16 is , has a one-to-one relationship with the laser intensity Φ. The constant A of Formula (1) is a material constant intrinsic|native to the construction object 17 here. That is, based on the laser intensity Φ obtained from the measured irradiation mark depth D, the impact pressure P applied to the object 17 to be worked can be obtained.

Formula (2) in FIG. 9 is a formula for deriving the pressure distribution σ(z) applied in the depth direction of the object 17 to be processed by laser peening. In general, when an impact is applied to a material surface as in laser peening, the pressure distribution σ(z) generated inside the object 17 to be processed depends on the magnitude of the impact pressure P, the material, and the spot, based on Hertz's theory of elastic contact. 19 and related to the size of Note that in equation (2), the size of the spot 19 is expressed as the radius a of the virtual circle.

In this way, based on the impact pressure P and the size of the spot 19 obtained from the measured irradiation mark depth D, the pressure in the depth direction z is applied to the object 17 irradiated with one pulse of the pulse laser 16. A distribution σ(z) is known. Based on this pressure distribution σ(z) in the depth direction, the compressive residual stress formed in the object 17 to be worked is estimated. Note that the compressive residual stress formed from the applied pressure distribution σ(z) is uniquely obtained for the material of the construction target 17 by numerical analysis, and is well known, so description thereof will be omitted.

When creating the database 42, the method of obtaining the residual stress 46 associated with the shape data 38 of the irradiation mark 14 is not limited to the method based on the above-described relational expression, and various methods are employed. For example, there is a method of forming irradiation traces 14 on the same material different from the object 17 and measuring the residual stress 46 by an X-ray stress measurement method combining sequential polishing or a perforation method.

10A and 10B are graphs showing the residual stress 46 with respect to the position of the laser spot 19. FIG. This graph represents temporal changes in the applied residual stress 46 . This graph is displayed on the display unit 12 during or after laser peening. Here, FIG. 10(A) shows that laser peening is progressing normally when the reference value 36 is -500 MPa. On the other hand, FIG. 10B shows that the laser peening progress is abnormal.

Further, an adjustment unit 35 can be provided in the monitoring unit 30B to adjust the irradiation conditions of the pulse laser 16 so that the deviation 39 becomes small. When the residual stress 46 is observed to be small, the driver 23 is instructed to increase the laser intensity (W/mm ² ) at the spot 19 . By providing the adjustment unit 35 in this way, even if the residual stress 46 changes during construction, the construction conditions of the driving unit 23 can be changed in real time.

As a result, the residual stress 46 can always be kept at the reference value 36 during construction, and the quality of the laser peening construction can be improved. In addition, if the residual stress 46 does not return to the reference value 36 even if the construction conditions are changed (for example, if the conditions are changed a predetermined number of times, or if the conditions cannot be changed due to hardware restrictions, etc. ) may activate an interlock to stop construction.

A laser peening method and a laser peening program according to the second embodiment will be described with reference to the flowchart of FIG. 11 (see FIG. 7 as needed). First, at the start of laser peening, a database 42 representing the relationship between the shape data 38 of the irradiation mark 14 and the residual stress 46 imparted to the object 17 to be treated is generated (S21). Further, the initial conditions for the irradiation conditions of the pulse laser 16 are determined (S22).

A photographed image 41 of the irradiation mark 14 formed on the irradiation surface 15 when the object 17 to be processed is peened by irradiating the pulse laser 16 is acquired (S23). The photographed image 41 may be photographed from a direction oblique to the irradiation axis 13 of the pulse laser 16 (FIG. 1), or may be photographed from a direction substantially coinciding with the irradiation axis 13 via the half mirror 26 (FIG. 2). can do.

The shape data 38 of the irradiation mark 14 is measured from the photographed image 41 (S24). Then, the residual stress 46 is estimated based on the shape data 38 of the measured irradiation mark 14 and the database 42 (S25). The photographed image 41 of the irradiation mark 14 and the residual stress 46 can be arbitrarily displayed on the display unit 12 .

A second deviation 39b between the residual stress 46 of the plurality of irradiation marks 14 formed by the pulse laser 16 intermittently irradiated and the second reference value 36b is calculated (S26). The second reference value 36b may be a predetermined set value, the stored residual stress 46 of the irradiation mark 14 formed in the past, or the average value or median value of a plurality of stored residual stresses 46. can do.

It is determined whether or not the second deviation 39b is less than the second threshold value 37b (S27). If it is determined to be less than (S27 Yes), the irradiation conditions of the pulse laser 16 are adjusted so that the second deviation 39b becomes smaller (S28), and the next laser spot 19 is irradiated with the pulse laser 16 (S29 No), the process returns to (S23) and this cycle is repeated. Then, when the peening construction to the construction target 17 is completed (S29 Yes), a series of the flow ends (END).

On the other hand, if it is determined that the second deviation 39b exceeds the second threshold value 37b (S27No), display a warning to make the operator aware of it, and then continue the flow (S30a, S28) or interlock. It is activated to forcibly terminate the peening operation (S30b, END).

The step of adjusting the irradiation conditions of the pulse laser 16 (S28) is optional and may be omitted. Further, in the above description of the flow, the residual stress 46 was sequentially determined each time the irradiation mark 14 was formed in the peening process. You may make it determine the stress 46 collectively.

According to the laser peening apparatus of at least one embodiment described above, by measuring the shape data of the irradiation mark from the photographed image of the irradiation mark, it is possible to confirm the quality assurance without actually measuring the residual stress after the construction. becomes possible.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof. Also, the constituent elements of the laser peening apparatus can be realized by a computer processor and can be operated by a laser peening program.

DESCRIPTION OF SYMBOLS 10 (10A, 10B, 10C)... Laser peening apparatus, 11... Camera, 12... Display part, 13... Irradiation axis, 14... Irradiation mark, 15... Irradiation surface, 16... Pulse laser, 17... Construction object, 18... Laser scanning unit 19 Laser spot 20 Laser irradiation unit 21 Laser oscillator 22 Condensing optical system 23 Driving unit 25 Mirror 26 Half mirror 27 Converging lens 28 Lens displacement Unit 30 (30A, 30B) Monitoring unit 31 Image acquiring unit 32 Measuring unit 33 (33a, 33b) Calculating unit 33a First calculating unit 33b Second calculating unit 34 (34a) , 34b)... determination unit 34a... first determination unit 34b... second determination unit 35... adjustment unit 36 (36a, 36b)... reference value 36a... first reference value 36b... second reference value, 37 (37a, 37b)... Threshold, 37a... First threshold, 37b... Second threshold, 38... Shape data, 39 (39a, 39b)... Deviation, 39a... First deviation, 39b... Second deviation, 41... Shooting Image, 42... Database, 45... Estimation part, 46... Residual stress.

Claims (11)

an image acquisition unit that acquires a photographed image of an irradiation mark formed on an irradiation surface when a construction target is peened by irradiating a pulse laser;
a measurement unit that measures shape data of the irradiation mark from the captured image;
a first calculator that calculates a first deviation between the shape data of the plurality of irradiation marks formed by the pulsed laser intermittently irradiated and a first reference value;
and a first determination unit that determines whether the first deviation is less than a first threshold value . an image acquisition unit that acquires a photographed image of an irradiation mark formed on an irradiation surface when a construction target is peened by irradiating a pulse laser;
a measurement unit that measures shape data of the irradiation mark from the captured image;
a database representing the relationship between the shape data of the irradiation mark and the residual stress imparted to the object to be processed;
and an estimating unit for estimating residual stress based on shape data of the irradiation mark measured from the photographed image and the database . In the laser peening apparatus according to claim 2 ,
a second calculator that calculates a second deviation between the residual stress and a second reference value;
and a second determination unit that determines whether the second deviation is less than a second threshold value. In the laser peening apparatus according to claim 1 ,
A laser peening apparatus comprising an adjustment unit that adjusts irradiation conditions of the pulse laser so that the first deviation becomes small. In the laser peening apparatus according to claim 3 ,
A laser peening apparatus comprising an adjustment unit that adjusts irradiation conditions of the pulse laser so that the second deviation becomes small. In the laser peening apparatus according to any one of claims 1 to 5 ,
The laser peening apparatus, wherein the photographed image is photographed from an oblique direction with respect to the irradiation axis of the pulse laser. In the laser peening apparatus according to any one of claims 1 to 5 ,
The laser peening apparatus, wherein the photographed image is photographed from a direction substantially coinciding with the irradiation axis through a half mirror that reflects the pulse laser. a step of obtaining a photographed image of an irradiation mark formed on an irradiation surface when a pulse laser is irradiated to peen a construction target;
a step of measuring shape data of the irradiation mark from the photographed image;
calculating a first deviation between the shape data of the plurality of irradiation marks formed by the intermittently irradiated pulse laser and a first reference value;
and determining whether the first deviation is less than a first threshold . a step of obtaining a photographed image of an irradiation mark formed on an irradiation surface when a pulse laser is irradiated to peen a construction target;
a step of measuring shape data of the irradiation mark from the photographed image;
forming a database representing the relationship between the shape data of the irradiation mark and the residual stress imparted to the object to be processed;
and estimating residual stress based on shape data of the irradiation mark measured from the photographed image and the database . to the computer,
Acquiring a photographed image of irradiation marks formed on the irradiated surface when the object to be worked is peened by irradiating the pulse laser;
measuring the shape data of the irradiation mark from the photographed image;
calculating a first deviation between the shape data of the plurality of irradiation marks formed by the intermittently irradiated pulse laser and a first reference value;
A laser peening program for executing a step of determining whether the first deviation is less than a first threshold value . to the computer,
Acquiring a photographed image of irradiation marks formed on the irradiated surface when the object to be worked is peened by irradiating the pulse laser;
measuring the shape data of the irradiation mark from the photographed image;
forming a database representing the relationship between the shape data of the irradiation mark and the residual stress imparted to the object to be processed;
a step of estimating residual stress based on the shape data of the irradiation mark measured from the photographed image and the database; and a laser peening execution program to be executed.

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