CN110824003A - Ultrasonic partition focusing detection method - Google Patents

Abstract

The invention belongs to the field of non-destructive testing, and relates to an ultrasonic subregion focusing detection method. The invention proposes a method for detecting the internal defects of metal materials by using a focusing probe, which overcomes the shortcomings of low detection sensitivity of ordinary flat probes, greatly improves the sensitivity of ultrasonic detection, and realizes ultrasonic nondestructive detection of small defects in the metal.

Description

A kind of ultrasonic zone focusing detection method

technical field

The invention relates to an ultrasonic subregion focusing detection method, which belongs to the field of non-destructive testing.

Background technique

During ultrasonic testing, due to the diffusion of the ultrasonic sound beam, the sound pressure at the farther away from the sound source is lower, resulting in a decrease in the echo of defects buried deeper and deeper, and the ultrasonic detection ability is weakened.

SUMMARY OF THE INVENTION

The present invention has designed a kind of ultrasonic subregion focusing detection method in view of the above-mentioned problems, and the purpose of the present invention is to realize through the following technical solutions:

The steps of the method are:

A method for ultrasonic subarea focused detection, comprising the steps of:

1.1 Place and partition the samples;

1.2 Connect the scanning equipment and select the ultrasonic probe;

1.3 Measure the effective sound beam width of the ultrasonic probe;

1.4 Set detection parameters;

1.5 Perform the scanning of the zones, set the starting point and end point of the scanning in the ultrasonic flaw detector, and start the scanning of the zones until the scanning of the zones is completed;

1.6 Repeat steps 1.2-1.5 until the detection of all partitions of the sample is completed.

In step 1.1, the requirement for the sample is that the surface roughness Ra of the sample is better than 0.8 μm, the sample is immersed in water, and the distance between the highest point of the sample and the water surface is greater than a quarter of the sample thickness h.

In step 1.1, the partitioning method of the sample partition is as follows: partition the sample according to different depths, record the machining allowance of the sample as a, a is a constant, and i _n is the depth increment of the nth partition; the depth of the first partition is a to a+i ₁ , the second partition from a+i ₁ to a+ _{i 2} , ..., the _mth partition from a+im _-1 to a+im , until a+im is greater than the sample thickness h, this The starting point of the last partition is a+im _-1 and the ending point is h.

The process of connecting equipment and ultrasonic probe selection in step 1.2 is as follows: the transmitting/receiving interface of the ultrasonic flaw detector is connected to the ultrasonic probe through a coaxial cable, and the ultrasonic probe is installed on a scanning frame or manipulator capable of The scanning frame or manipulator controls the ultrasonic probe to make it perpendicular to the surface of the sample, and keeps the distance Wp between the end face of the ultrasonic probe and the sample surface as g. If the sample surface is a curved surface, the ultrasonic probe is controlled by the scanning frame or the manipulator so that its axis is aligned with the sample. The surface normals are coincident, and keep Wp as g, g= _f -2(2a+im _-1 +im), f is the focal length of the ultrasonic probe, g is greater than a quarter of h and greater than 50mm, if the conditions, use an ultrasonic probe with a larger focal length.

In step 1.2, a standard test block with a cylindrical flat-bottom hole with a buried depth of a+i _m-1 is selected, so that the axis of the ultrasonic probe coincides with the axis of the standard test block and the distance between the end face of the ultrasonic probe and the upper end face of the standard test block is g, and adjust the ultrasonic flaw detector. The sensitivity of the flat-bottom hole makes the reflected echo reach 80% of the full screen, the sensitivity at this time is G _m-1 , select a standard test block with a buried depth of a+ _{im, repeat the above process, and get the sensitivity G m ,} |G _m -G _m-1 | should be less than Δ, if this condition is not met, re-select the ultrasonic probe.

Step 1.3 The process of measuring the effective sound beam width of the ultrasonic probe is as follows: select a series of cylindrical flat-bottom hole standard test blocks with a buried depth from dmin to dmax, where dmin is not greater than a+i _m-1 and dmax is not less than a+i _m , make the axis of the ultrasonic probe coincide with the axis of the standard test block with a buried depth of dmin and the distance between the end face of the ultrasonic probe and the upper end face of the standard test block is g, adjust the sensitivity of the ultrasonic flaw detector so that the reflected echo of the flat bottom hole reaches 80% of the full screen, The sensitivity at this time is Gmin. Move the ultrasonic probe along the aperture direction of the flat-bottomed hole until the reflected echo from the flat-bottomed hole reaches 40% of the full screen. At this time, the moving distance of the ultrasonic probe is Pmin, and the sound beam width of the ultrasonic probe is 2Pmin. Repeat The above steps are performed until the sound beam width 2Pmax of the ultrasonic probe corresponding to the standard test block with a buried depth of dmax is obtained, then among the measured values of the sound beam width of the standard test block with a series of cylindrical flat-bottomed holes between dmin and dmax, the minimum value is selected as the ultrasonic sound beam width 2Pmax. The effective beam width of the probe.

Step 1.4 The process of setting detection parameters is as follows:

Adjust sensitivity

Select a series of cylindrical flat-bottom hole standard test blocks with buried depths from dmin to dmax, where dmin is not greater than a+im _-1 and dmax is not less than a+ _im , open the distance amplitude compensation editing function of the ultrasonic flaw detector, Make the axis of the ultrasonic probe coincide with the axis of the standard test block with a buried depth of dmin, and the distance between the end face of the ultrasonic probe and the upper end face of the standard test block is g, and adjust the sensitivity of the ultrasonic flaw detector so that the reflected echo of the flat-bottom hole reaches 80% of the full screen. The sensitivity is Gmin, input the burial depth dmin and Gmin into the DAC list of the flaw detector, repeat the above steps, obtain all the sensitivity values of the standard test block with the buried depth from dmin to dmax, and calculate the buried depth of all the standard test blocks. Input its corresponding sensitivity value into the DAC list of the flaw detector, after saving, the ultrasonic flaw detector will form the DAC curve of the ultrasonic probe in this partition, open or call the curve, and then adjust the sensitivity of the ultrasonic flaw detector, increase or reduce sensitivity A;

Adjust the sampling gate

Adjust the sampling gate of the ultrasonic flaw detector so that the starting point is a+i _{m -1} -s1 and the end point is a+im +s2. If it is the first partition, the starting point of the sampling gate is the machining allowance a of the sample, and s1 is The distance between the starting depth of the partition and the starting point of the sampling gate, s2 is the distance between the end point of the sampling gate and the end depth of the partition, if it is the last partition, the ending point of the sampling gate is h-1mm or h-1.5mm, and the height of the sampling gate is not above 40% of full screen,

Set scan parameters

Set the scanning spacing in the ultrasonic flaw detector, and the scanning spacing is not greater than one-third of the effective sound beam width. Set the repetition frequency in the ultrasonic flaw detector. The repetition frequency should be as large as possible without the occurrence of phantom waves. , Set the scanning speed in the ultrasonic flaw detector, and the scanning speed should not be greater than the product of the repetition frequency and the scanning spacing.

The partition of step 1.1 is carried out in the following way:

Table 1: Partitioning methods

area code 1 2 3 4 5 6 7 Starting depth mm Machining allowance a 13 25 38 50 63 89 End depth mm 13 25 38 50 63 89 140

The partition of step 1.1 is carried out in the following way:

Table 2: Partitioning methods

The partition of step 1.1 is carried out in the following way:

Table 3: Partitioning methods

area code 1 2 3 4 Starting depth mm Machining allowance a 25 50 76 End depth mm 25 50 76 140

The advantages and beneficial effects of the present invention are:

The present invention develops an ultrasonic subregion focused detection method, which overcomes the problem of decreased defect detection sensitivity caused by ultrasonic sound beam diffusion in non-subregional detection, and realizes high-sensitivity ultrasonic inspection of samples.

Detailed ways

The working principle of the present invention is:

The focused ultrasound probe has the strongest ability to find defects in its focusing area. Using this feature, the present invention divides the sample into different regions, uses focusing probes of different specifications or adjusts the water distance of the probe to adjust the focusing depth, thereby making the sample buried in different depths. The defects are all in the focus area, which improves the detection ability of ultrasonic testing.

Example 1

For the FGH96 powder superalloy sample with a thickness of 140mm, the sub-regional focusing detection steps are as follows:

The steps of the method are:

1.1 Sample requirements and placement

The surface roughness Ra of the sample is processed to be better than 0.8μm, the sample is immersed in water, and the distance between the highest point of the sample and the water surface is 200mm,

1.2 Sample Partitioning

Partition the samples according to the table below

Partitioning

Use steps 1.3-1.8 to detect each partition:

1.3 Connection equipment and probe selection

The transmit/receive interface of the ultrasonic flaw detector is connected to the ultrasonic probe through a coaxial cable. The ultrasonic probe is installed on a scanning frame or a manipulator capable of multi-axis coordinated motion. The scanning frame or the manipulator controls the probe to make it perpendicular to the surface of the sample Keep the distance Wp between the probe end face and the sample surface as g. If the sample surface is a curved surface, control the probe through the scanning frame or manipulator to make its axis coincide with the normal line of the sample surface, and keep the water distance at g, g=probe focal length f-2 (2a+i _m-1 +i _m ) and g is greater than 50mm, if g is not greater than 50mm, use a probe with a larger focal length,

Select a standard test block with a cylindrical flat bottom hole with a buried depth of a+i _m-1 , make the axis of the probe coincide with the axis of the standard test block and the distance between the probe end face and the upper end face of the standard test block is g, and adjust the sensitivity of the ultrasonic flaw detector to make the flat bottom hole The reflected echo reaches 80% of the full screen, and the sensitivity at this time is G _m-1 . Select a standard test block with a buried depth of a+ _im , and repeat the above process to obtain a sensitivity of G _m , |G _m -G _{m- 1} | Should be less than 2dB, if this condition is not met, re-select the probe,

1.4 Measuring the effective sound beam width of the probe

Select a series of standard test blocks with cylindrical flat-bottomed holes with a buried depth from dmin to dmax, where dmin is not greater than a+in _-1 and dmax is not less than a ₊ in, so that the probe axis and the buried depth are the standard test blocks of dmin. The axis of the block is coincident and the distance between the probe end face and the upper end face of the standard test block is g. Adjust the sensitivity of the ultrasonic flaw detector so that the reflected echo of the flat-bottom hole reaches 80% of the full screen. The sensitivity at this time is Gmin. Move the probe along the direction of the flat-bottom hole aperture. , until the reflected echo of the flat-bottomed hole reaches 40% of the full screen. At this time, the moving distance of the probe is Pmin, and the sound beam width of the probe is 2Pmin. Repeat the above steps until the sound beam width of the probe corresponding to the standard test block with a buried depth of dmax is obtained. 2Pmax, 2Pmin to 2Pmax and the minimum value of the sound beam width of all the measured probes between them as the effective sound beam width of the probe,

1.5 Adjust the sensitivity

Select a series of cylindrical flat-bottom hole standard test blocks with buried depths from dmin to dmax, where dmin is not greater than a+im _-1 , dmax is not less than a+ _im , and the distance amplitude compensation (DAC) of the ultrasonic flaw detector is turned on. Edit function, make the axis of the probe coincide with the axis of the standard test block with the buried depth of dmin, and the distance between the probe end face and the upper end face of the standard test block is g, and adjust the sensitivity of the ultrasonic flaw detector to make the reflected echo of the flat bottom hole reach 80% of the full screen. When the sensitivity is Gmin, enter the burial depth dmin and Gmin into the DAC list of the flaw detector, and repeat the above steps until the ultrasonic flaw detector sensitivity Gmax and burial depth dmax corresponding to the standard test block with burial depth dmax are input into the flaw detector. In the DAC list, after saving, the ultrasonic flaw detector will form the DAC curve of the probe under this partition, open or call the curve, and then adjust the sensitivity of the ultrasonic flaw detector, increase or decrease the sensitivity A,

1.6 Adjusting the sampling gate

Adjust the sampling gate of the ultrasonic flaw detector so that the starting point is a+i _{m -1} -2mm, and the end point is a+im +2mm. If it is the first area, the starting point of the sampling gate is the machining allowance a of the sample. In the last area, the end point of the sampling gate is 139mm, and the height of the sampling gate is 10% of the full screen.

1.7 Set scan parameters

Set the scanning spacing in the ultrasonic flaw detector, and the scanning spacing is not greater than one-third of the effective sound beam width. Set the repetition frequency in the ultrasonic flaw detector. The repetition frequency should be as large as possible without the occurrence of phantom waves. , set the scanning speed in the ultrasonic flaw detector, the scanning speed is not greater than the product of the repetition frequency and the scanning spacing,

1.8 Scanning

Set the scanning start and end points in the ultrasonic flaw detector, start scanning until the scanning is completed,

1.9 Repeat steps 1.3-1.8 until the detection of all partitions is completed,

Example 2

For the FGH96 powder superalloy sample with a thickness of 35mm, the sub-regional focusing detection steps are as follows:

The steps of the method are:

1.1 Sample requirements and placement

The surface roughness Ra of the sample is processed to be better than 0.8μm, the sample is immersed in water, and the distance between the highest point of the sample and the water surface is 100mm,

1.2 Sample Partitioning

Partition the samples according to the table below

Partitioning 2

area code 1 2 3 4 5 6 Starting depth mm Machining allowance a 6 13 19 25 32 End depth mm 6 13 19 25 32 35

For each partition, use steps 1.3-1.8 to detect:

1.3 Connection equipment and probe selection

The transmit/receive interface of the ultrasonic flaw detector is connected to the ultrasonic probe through a coaxial cable. The ultrasonic probe is installed on a scanning frame or a manipulator capable of multi-axis coordinated motion. The scanning frame or the manipulator controls the probe to make it perpendicular to the surface of the sample Keep the distance Wp between the probe end face and the sample surface as g. If the sample surface is a curved surface, control the probe through the scanning frame or manipulator to make its axis coincide with the normal line of the sample surface, and keep the water distance at g, g=probe focal length f-2 (2a+i _m-1 +i _n ) and g is greater than 50mm, if g is not greater than 50mm, use a probe with a larger focal length,

Select a standard test block with a cylindrical flat bottom hole with a buried depth of a+i _m-1 , make the axis of the probe coincide with the axis of the standard test block and the distance between the probe end face and the upper end face of the standard test block is g, and adjust the sensitivity of the ultrasonic flaw detector to make the flat bottom hole The reflected echo reaches 80% of the full screen, and the sensitivity at this time is G _m-1 . Select a standard test block with a buried depth of a+ _im , and repeat the above process to obtain a sensitivity of G _m , |G _m -G _{m- 1} | Should be less than 1dB, if this condition is not met, re-select the probe,

1.4 Measuring the effective sound beam width of the probe

Select a series of standard test blocks with cylindrical flat-bottomed holes with buried depths from dmin to dmax, where dmin is not greater than a+im _-1 and dmax is not less than a+ _im , so that the probe axis and the buried depth are the standard test blocks of dmin. The axis of the block is coincident and the distance between the probe end face and the upper end face of the standard test block is g. Adjust the sensitivity of the ultrasonic flaw detector so that the reflected echo of the flat-bottom hole reaches 80% of the full screen. The sensitivity at this time is Gmin. Move the probe along the direction of the flat-bottom hole aperture. , until the reflected echo of the flat-bottomed hole reaches 40% of the full screen. At this time, the moving distance of the probe is Pmin, and the sound beam width of the probe is 2Pmin. Repeat the above steps until the sound beam width of the probe corresponding to the standard test block with a buried depth of dmax is obtained. 2Pmax, 2Pmin to 2Pmax and the minimum value of the sound beam width of all the measured probes between them as the effective sound beam width of the probe,

1.5 Adjust the sensitivity

Select a series of cylindrical flat-bottom hole standard test blocks with buried depths from dmin to dmax, where dmin is not greater than a+im _-1 and dmax is not less than a+ _im , open the distance amplitude compensation editing function of the ultrasonic flaw detector, Make the axis of the probe coincide with the axis of the standard test block with a buried depth of dmin, and the distance between the probe end face and the upper end face of the standard test block is g, adjust the sensitivity of the ultrasonic flaw detector so that the reflected echo of the flat-bottom hole reaches 80% of the full screen, and the sensitivity at this time is For Gmin, input the burial depth dmin and Gmin into the DAC list of the flaw detector, and repeat the above steps until the ultrasonic flaw detector sensitivity Gmax and burial depth dmax corresponding to the standard test block whose burial depth is dmax are input into the DAC list of the flaw detector , after saving, the ultrasonic flaw detector will form the DAC curve of the probe under this partition, open or call the curve, and then adjust the sensitivity of the ultrasonic flaw detector, increase or decrease the sensitivity A,

1.6 Adjusting the sampling gate

Adjust the sampling gate of the ultrasonic flaw detector so that the starting point is a+i _{m -1} -2mm, and the end point is a+im +2mm. If it is the first area, the starting point of the sampling gate is the machining allowance a of the sample. In the last area, the end point of the sampling gate is 34mm, and the height of the sampling gate is 20% of the full screen.

1.7 Set scan parameters

Set the scanning spacing in the ultrasonic flaw detector, and the scanning spacing is not greater than one-third of the effective sound beam width. Set the repetition frequency in the ultrasonic flaw detector. The repetition frequency should be as large as possible without the occurrence of phantom waves. , set the scanning speed in the ultrasonic flaw detector, the scanning speed is not greater than the product of the repetition frequency and the scanning spacing,

1.8 Scanning

Set the scanning start and end points in the ultrasonic flaw detector, start scanning until the scanning is completed,

1.9 Repeat steps 1.3-1.8 until the detection of all partitions is completed,

Ultrasonic probe frequency can be selected from 5MHz, 10MHz, 15MHz, 20MHz, etc., probe chip diameter can be selected from 9.5mm, 11mm, 12.7mm, 19mm, 25mm, etc., probe focal length can be selected from 76mm, 89mm, 100mm, 150mm, 152mm, 200mm, 250mm, 330mm, 400mm.

Claims (10)

1. An ultrasonic subarea focusing detection method is characterized by comprising the following steps:

1.1 placing and partitioning the sample;

1.2 connecting scanning equipment and selecting an ultrasonic probe;

1.3, measuring the effective sound beam width of the ultrasonic probe;

1.4 setting detection parameters;

1.5, scanning in a subarea, setting a scanning starting point and a scanning end point in the ultrasonic flaw detector, and starting subarea scanning until subarea scanning is finished;

1.6 repeat steps 1.2-1.5 until detection of all the partitions of the sample is completed.

2. The method of claim 1, wherein in step 1.1, the sample is required to have a surface roughness Ra of better than 0.8 μm, and the sample is immersed in water with a distance between the highest point of the sample and the water surface of more than a quarter of the thickness h of the sample.

3. The ultrasonic zone-focusing detection method according to claim 2, characterized in that in step 1.1, the zone-dividing method of the sample zone is as follows: partitioning the sample according to different depths, recording the machining allowance of the sample as a, a as a constant and i_nDepth increment for nth partition; the depth of the first partition is a to a + i₁The second partition is from a + i₁To a + i₂… …, m-th partition from a + i_m-1To a + i_mUp to a + i_mGreater than the sample thickness h, at which point the starting point of the last partition is a + i_m-1The end point is h.

4. The ultrasound zonal focus detection method of claim 3, wherein the process of connecting equipment and ultrasound probe selection in step 1.2 is as follows: the transmitting/receiving interface of the ultrasonic flaw detector is connected with the ultrasonic probe through a coaxial cable, the ultrasonic probe is arranged on a scanning frame or a mechanical arm which can do multi-axis cooperative motion, the ultrasonic probe is controlled by the scanning frame or the mechanical arm to be vertical to the surface of the sample, the distance Wp between the end surface of the ultrasonic probe and the surface of the sample is kept to be g, if the surface of the sample is a curved surface, the ultrasonic probe is controlled by the scanning frame or the mechanical arm to enable the axis of the ultrasonic probe to coincide with the normal of the surface of the sample, and the distance Wp is kept to be g, wherein g is f-2(2a + i)_m-1+i_m) F is the focal length of the ultrasonic probe, g is more than one fourth of h and more than 50mm, and if the condition is not met, the ultrasonic probe with the larger focal length is adopted.

5. The ultrasonic zone-focusing detection method according to claim 4, characterized in that the buried depth a + i is selected in step 1.2_m-1The cylindrical flat-bottom hole standard test block ensures that the axis of the ultrasonic probe is coincided with the axis of the standard test block, the distance between the end surface of the ultrasonic probe and the upper end surface of the standard test block is G, the sensitivity of the ultrasonic flaw detector is adjusted to ensure that the reflection echo of the flat-bottom hole reaches 80 percent of the full screen, and the sensitivity at the moment is G_m-1The depth of burial is selected to be a + i_mRepeating the above process to obtain a standard test block with sensitivity G_m，|G_m-G_m-1If the condition is not met, | should be less than Δ, the ultrasound probe is reselected.

6. The ultrasonic zone-focusing detection method according to claim 4, wherein the step 1.3 of measuring the effective beam width of the ultrasonic probe comprises the following steps: selecting a series of cylindrical flat-bottom hole standard test blocks with the burial depth from dmin to dmax, wherein dmin is not more than a + i_m-1Dmax is not less than a + i_mThe axial line of the ultrasonic probe is made to coincide with the axial line of a standard test block with the burial depth dmin, the distance between the end face of the ultrasonic probe and the upper end face of the standard test block is g, the sensitivity of the ultrasonic flaw detector is adjusted to enable the reflection echo of the flat-bottom hole to reach 80% of the full screen, the sensitivity at the moment is Gmin, the ultrasonic probe is moved along the aperture direction of the flat-bottom hole until the reflection echo of the flat-bottom hole reaches 40% of the full screen, the moving distance of the ultrasonic probe is Pmin, the sound beam width of the ultrasonic probe is 2Pmin, the steps are repeated until the sound beam width 2Pmax of the ultrasonic probe corresponding to the standard test block with the burial depth dmax is obtained, and the minimum value is selected as the effective sound beam width of the ultrasonic probe in the sound beam width measured values of the series of the flat-bottom hole standard test.

7. The ultrasound zone-focusing detection method according to claim 6, wherein the step 1.4 sets the detection parameter process to:

adjusting sensitivity

Selecting a series of cylindrical flat-bottom hole standard test blocks with the burial depth from dmin to dmax, wherein dmin is not more than a + i_m-1Dmax is not less than a + i_mOpening the distance amplitude compensation editing function of the ultrasonic flaw detector to enable the axis of the ultrasonic probe to coincide with the axis of a standard test block with the burial depth dmin and enable the distance between the end face of the ultrasonic probe and the upper end face of the standard test block to be g, adjusting the sensitivity of the ultrasonic flaw detector to enable the reflection echo of a flat-bottom hole to reach 80% of the full screen, enabling the sensitivity to be Gmin at the moment, inputting the burial depths dmin and Gmin into a DAC list of the flaw detector, repeating the steps to obtain all sensitivity values of the standard test block with the burial depth from dmin to dmax, inputting the burial depths of all the standard test blocks and the corresponding sensitivity values into the DAC list of the flaw detector, forming a DAC curve of the ultrasonic probe under the subarea by the ultrasonic flaw detector after storage, opening or calling the curve, then adjusting the sensitivity of the ultrasonic flaw detector to increase or decrease the sensitivity A,

adjustable sampling door

Adjusting a sampling gate of the ultrasonic flaw detector to enable the starting point to be a + i_m-1S1, end point a + i_m+ s2, if the first partition is the sample machining allowance a, s1 is the distance between the starting depth of the partition and the starting point of the sampling gate, s2 is the distance between the ending point of the sampling gate and the ending depth of the partition, if the last partition is the sampling gate, the ending point of the sampling gate is h-1mm or h-1.5mm, the height of the sampling gate is not higher than 40% of the full screen,

setting scanning parameters

Setting a scanning interval in the ultrasonic flaw detector, wherein the scanning interval is not more than one third of the width of an effective sound beam, setting a repetition frequency in the ultrasonic flaw detector, the repetition frequency is selected to be as large as possible on the premise of not generating phantom waves, and setting a scanning speed in the ultrasonic flaw detector, wherein the scanning speed is not more than the product of the repetition frequency and the scanning interval.

8. The ultrasonic zone-focusing inspection method of claim 3, characterized in that the zone division of step 1.1 is performed in the following manner:

table 1: partition mode

Area code 1 2 3 4 5 6 7 Starting depth mm Allowance a for machining 13 25 38 50 63 89 End depth mm 13 25 38 50 63 89 140

9. The ultrasonic zone-focusing inspection method of claim 3, characterized in that the zone division of step 1.1 is performed in the following manner:

table 2: partition mode

Area code 1 2 3 4 5 6 Starting depth mm Allowance a for machining 6 13 19 25 32 End depth mm 6 13 19 25 32 38

10. The ultrasonic zone-focusing inspection method of claim 3, characterized in that the zone division of step 1.1 is performed in the following manner:

table 3: partition mode

Area code 1 2 3 4 Starting depth mm Allowance a for machining 25 50 76 End depth mm 25 50 76 140