Method for measuring trace oil storage quantity on surface of steel plate

Abstract

The invention discloses a steel plate surface trace oil storage amount measurement method, which uses a three-dimensional measurement function of a laser scanning confocal microscope to carry out three-dimensional scanning measurement on the steel plate surface trace oil storage amount, and obtains a micro oil storage amount three-dimensional image formed by a data array. The method comprises the following steps: 1, scanning the surface appearance of a to-be-measured steel plate by using a confocal microscope, and measuring the appearance once by penetrating through the surface of the oil film scanning steel plate; 2, performing low-sensitivity top surface scanning on the steel plate to be measured by adopting a confocal microscope, measuring a position where signal change occurs, and measuring secondary morphology of the top surface; 3, overlay analysis is conducted on the primary / secondary morphology data, the oil film coverage volume is obtained, in the first step, a confocal microscope penetrates through the oil film to scan the surface of the steel plate, discontinuous tomography imaging is conducted in the Z-axis direction of the to-be-measured steel plate, and sequence scanning is conducted in the axis direction at the interval of 5 micrometers.

Description

Technical Field

[0001] The invention belongs to the technical field of oil quantity measurement, and in particular relates to a method for measuring the amount of trace oil stored on the surface of a steel plate. Background Art

[0002] The application of steel plates in advanced manufacturing industries such as the automotive industry is quite demanding, requiring a smooth surface with good stamping lubrication and no rust. For the determination of oil content on the surface of cold-rolled, galvanized and other steel plates used in the automotive industry, the two main methods used are chemical weight loss analysis, which can be accurately quantified, and optical measurement using an oil film thickness gauge, which can roughly measure the thickness. Among them, the chemical weight loss analysis method has a slow detection speed, a complex procedure, and a large workload, and it is difficult to meet the requirements of rapid on-site analysis in the steel and automotive industries.

[0003] The measurement based on optical principle usually includes three types of oil film thickness gauges, namely laser fluorescence method, infrared spectral absorption method and infrared spectral interferometry method. Usually, a special infrared laser source is used to perform non-contact measurement of the oil film thickness on the strip surface. After the infrared light passes through the oil film, part of it is absorbed and part of it is reflected back. The thickness of the oil film is measured by the change in infrared intensity, i.e. absorbance. However, this method of measuring the oil film thickness ignores the influence of the uneven microscopic morphology of the steel plate surface. It is suitable for situations where the amount of oil is large (higher than the wave crest). In addition, due to vibration, tilt and other reasons, the actual measurement often results in large fluctuations in the measurement data and different thicknesses in multiple locations. It cannot be applied to measurements with less oil.

[0004] In view of the above factors, a method for measuring the amount of trace oil on the surface of a steel plate is provided to achieve quantifiable and easy-to-operate measurement of the amount of residual oil in the trace oil film on the surface of the steel plate. Summary of the invention

[0005] The purpose of the present invention is to provide a method for measuring the amount of trace oil on the surface of a steel plate to solve the problems raised in the above-mentioned background technology.

[0006] The object of the present invention is achieved through the following technical scheme: a method for measuring the amount of micro-oil on the surface of a steel plate, using the three-dimensional measurement function of a laser scanning confocal microscope to perform three-dimensional scanning measurement on the amount of micro-oil on the surface of the steel plate, and obtaining a three-dimensional image of the micro-oil composed of a data array, comprising the following steps;

[0007] In the first step, a confocal microscope is used to scan the surface morphology of the steel plate to be tested, and the surface of the steel plate is scanned through the oil film to measure the morphology once;

[0008] In the second step, a confocal microscope is used to scan the top surface of the steel plate under test with low sensitivity, and the position where the signal change occurs is measured, and the secondary morphology of the top surface is measured;

[0009] The third step is to perform superposition analysis on the above primary / secondary morphological data to obtain the oil film coverage volume.

[0010] Furthermore, in the first step, the confocal microscope penetrates the oil film to scan the surface of the steel plate to perform discontinuous tomographic scanning imaging along the Z-axis direction of the steel plate to be tested, and performs sequential scanning in the axial direction at intervals of 5 um.

[0011] Furthermore, in the second step, a low-sensitivity top surface scan of the steel plate to be tested is performed using a cofocal microscope, discontinuous tomographic imaging is performed along the Z-axis direction of the steel plate to be tested, and sequential scanning is performed in the axial direction at intervals of 5 um.

[0012] Furthermore, the laser scanning confocal microscope is used to perform discontinuous tomographic imaging at 5 um intervals, and the steel plate to be tested has a scanning range of 360 mm x 200 um in the X and Y directions to obtain a two-dimensional image;

[0013] The obtained two-dimensional series of images were pre-processed by filtering and noise reduction to improve the image continuity and visual effect, and reconstructed using the 3D reconstruction function of the laser scanning confocal microscope.

[0014] Furthermore, during the confocal microscope scanning measurement process, a scanning height range covering the entire oil film morphology is determined, and data is collected point by point and layer by layer by the confocal microscope scanning laser. The data of each layer is obtained, and envelope fitting is performed on all the data to obtain a three-dimensional data set of the oil film morphology, that is, the three-dimensional coordinates of each point within the measurement area.

[0015] Furthermore, the confocal microscope scans in an XYZ mode to obtain confocal images, and during scanning, layer cutting is performed along the Z axis to obtain images in the XY plane, the layer cutting interval is 5um, and scanning is performed at a resolution of 1024x1024 and a speed of 100Hz. All XY plane images are reconstructed to obtain images of trace oil deposits on the steel plate surface and a three-dimensional image of their distribution.

[0016] Furthermore, the confocal microscope uses a laser with a wavelength of 488nm to scan and obtain layer-by-layer two-dimensional grayscale images, with the interval between images in the z-axis direction being a selected step length. After preprocessing the tomographic image with image smoothing and image enhancement, the image is stored in an image stack and sorted in a scanning order. Computer image processing is used to form a maximum brightness image and a three-dimensional height-encoded image, and the height-encoded image contains three-dimensional height information of the surface morphology.

[0017] Furthermore, computer image processing is used to form a maximum brightness image and a three-dimensional height-encoded image to perform superposition analysis on the primary / secondary morphological data to obtain the oil film coverage volume.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention can achieve quantifiable and easy-to-operate measurement of the residual oil amount of the trace oil film on the surface of the steel plate, calculate the accurate surface oil amount, and solve the problem that the traditional measurement method is complicated or inaccurate.

[0020] The present invention utilizes a laser confocal scanning microscope to perform layered scanning measurement on the measured oil film, and performs subsequent processing on the measured data, thereby providing an effective means for direct and precise measurement and characterization of the microstructure of the oil film, and can effectively improve the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of three-dimensional scanning of the laser confocal microscope of the present invention;

[0022] Figure 2 It is a three-dimensional schematic diagram of scanning the surface morphology of the steel plate to be tested according to the present invention;

[0023] Figure 3 It is a two-dimensional schematic diagram of scanning the surface morphology of the steel plate to be tested according to the present invention;

[0024] Figure 4 It is a three-dimensional schematic diagram of the oil film morphology scanning on the surface of the steel plate to be tested according to the present invention;

[0025] Figure 5 It is a two-dimensional schematic diagram of scanning the oil film morphology on the surface of the steel plate to be tested according to the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention. Specific embodiment one:

[0030] like Figure 1-5 As shown, a method for measuring the amount of micro-oil on the surface of a steel plate uses the three-dimensional measurement function of a laser scanning confocal microscope to perform three-dimensional scanning measurement on the amount of micro-oil on the surface of the steel plate, and obtains a three-dimensional image of the micro-oil composed of a data array, including the following steps;

[0031] In the first step, a confocal microscope is used to scan the surface morphology of the steel plate to be tested, and the surface of the steel plate is scanned through the oil film to measure the morphology once;

[0032] In the first step, the confocal microscope penetrates the oil film to scan the surface of the steel plate to perform discontinuous tomographic imaging along the Z-axis direction of the steel plate to be tested, and performs sequential scanning in the axial direction at intervals of 5um.

[0033] The laser scanning confocal microscope is used to perform discontinuous tomographic imaging at 5 um intervals, and the steel plate to be tested has a scanning range of 360 mm x 200 um in the X and Y directions to obtain a two-dimensional image;

[0034] Among them, the sizes of X and Y are the length and width of the tomographic image, and Z is the longitudinal scanning range.

[0035] The obtained two-dimensional series of images were pre-processed by filtering and noise reduction to improve the image continuity and visual effect, and reconstructed using the 3D reconstruction function of the laser scanning confocal microscope.

[0036] A confocal microscope with a wavelength of 488nm laser is used to scan the steel plate to obtain layer-by-layer two-dimensional grayscale images. The interval between images in the z-axis direction is a selected step length. After preprocessing the tomographic image with image smoothing and image enhancement, the image is stored in an image stack and sorted in the scanning order. Computer image processing is used to form a maximum brightness image and a three-dimensional height-encoded image. The height-encoded image contains three-dimensional height information of the surface morphology. Specific embodiment 2:

[0038] Different from the first specific embodiment, Figure 1-5 As shown;

[0039] In the second step, a confocal microscope is used to scan the top surface of the steel plate under test with low sensitivity, and the position where the signal change occurs is measured, and the secondary morphology of the top surface is measured;

[0040] In the second step, a low-sensitivity top surface scan of the steel plate to be tested is performed using a co-focusing microscope, discontinuous tomographic imaging is performed along the Z-axis direction of the steel plate to be tested, and sequential scanning is performed in the axial direction at intervals of 5 μm.

[0041] The laser scanning confocal microscope is used to perform discontinuous tomographic imaging at 5 um intervals, and the steel plate to be tested has a scanning range of 360 mm x 200 um in the X and Y directions to obtain a two-dimensional image;

[0042] The obtained two-dimensional series of images were pre-processed by filtering and noise reduction to improve the image continuity and visual effect, and reconstructed using the 3D reconstruction function of the laser scanning confocal microscope.

[0043] Among them, the scanning height range covering the entire oil film morphology is determined during the confocal microscope scanning measurement process. The confocal microscope scanning laser scans point by point and layer by layer to collect data, obtains the data of each layer, performs envelope fitting on all the data, and obtains a three-dimensional data set of the oil film morphology, that is, the three-dimensional coordinates of each point within the measurement area.

[0044] The confocal microscope scans in an XYZ mode to obtain confocal images. During scanning, layer cutting is performed along the Z axis to obtain images in the XY plane. The layer cutting interval is 5um. The resolution of 1024x1024 and the speed of 100Hz are used for scanning. All XY plane images are reconstructed to obtain images of trace oil storage on the surface of the steel plate and a three-dimensional image of distribution.

[0045] The confocal microscope uses a laser with a wavelength of 488nm to scan and obtain two-dimensional grayscale images layer by layer, with the interval between images in the z-axis direction being a selected step length. After preprocessing the tomographic image with image smoothing and image enhancement, the image is stored in an image stack and sorted in a scanning order. A maximum brightness image and a three-dimensional height-encoded image are formed using computer image processing, and the height-encoded image contains three-dimensional height information of the surface morphology.

[0046] The third step is to perform superposition analysis on the above primary / secondary morphology data, and use computer image processing to form a maximum brightness image and a three-dimensional height-coded image to perform superposition analysis on the primary / secondary morphology data to obtain the oil film coverage volume.

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for measuring the amount of trace oil on the surface of a steel plate, characterized in that: Using the three-dimensional measurement function of a laser scanning confocal microscope to perform three-dimensional scanning measurement on the micro-oil amount on the surface of the steel plate, and obtaining a three-dimensional image of the micro-oil amount composed of a data array, including the following steps; In the first step, a confocal microscope is used to scan the surface morphology of the steel plate to be tested, and the surface of the steel plate is scanned through the oil film to measure the morphology once; In the second step, a confocal microscope is used to scan the top surface of the steel plate under test with low sensitivity, and the position where the signal change occurs is measured, and the secondary morphology of the top surface is measured; The third step is to perform superposition analysis on the above primary / secondary morphological data to obtain the oil film coverage volume.

2. The method for measuring the amount of oil stored on the surface of a steel plate according to claim 1, characterized in that: In the first step, the confocal microscope penetrates the oil film to scan the surface of the steel plate to perform discontinuous tomographic scanning imaging along the Z-axis direction of the steel plate to be tested, and performs sequential scanning in the axial direction at intervals of 5 um.

3. The method for measuring the amount of oil stored on the surface of a steel plate according to claim 2, characterized in that: In the second step, a low-sensitivity top surface scan of the steel plate to be tested is performed using a co-focusing microscope, discontinuous tomographic imaging is performed along the Z-axis direction of the steel plate to be tested, and sequential scanning is performed in the axial direction at intervals of 5 μm.

4. The method for measuring the amount of micro-oil on the surface of a steel plate according to claim 3, characterized in that: The laser scanning confocal microscope is used to perform discontinuous tomographic imaging at 5 um intervals, and the steel plate to be tested has a scanning range of 360 mm x 200 um in the X and Y directions to obtain a two-dimensional image; The obtained two-dimensional series of images were pre-processed by filtering and noise reduction to improve the image continuity and visual effect, and reconstructed using the 3D reconstruction function of the laser scanning confocal microscope.

5. The method for measuring the amount of micro-oil on the surface of a steel plate according to claim 4, characterized in that: During the confocal microscope scanning measurement process, a scanning height range covering the entire oil film morphology is determined, and data is collected point by point and layer by layer by scanning laser of the confocal microscope, and the data of each layer is obtained to perform envelope fitting on all the data to obtain a three-dimensional data set of the oil film morphology, that is, the three-dimensional coordinates of each point within the measurement area.

6. The method for measuring the amount of oil stored on the surface of a steel plate according to claim 5, characterized in that: The confocal microscope scans in an XYZ mode to obtain confocal images. During scanning, layer cutting is performed along the Z axis to obtain images in the XY plane. The layer cutting interval is 5um. The resolution of 1024x1024 and the speed of 100Hz are used for scanning. All XY plane images are reconstructed to obtain images of trace oil storage on the surface of the steel plate and a three-dimensional image of distribution.

7. The method for measuring the amount of oil stored on the surface of a steel plate according to claim 6, characterized in that: The confocal microscope uses a laser with a wavelength of 488nm to scan and obtain two-dimensional grayscale images layer by layer, with the interval between images in the z-axis direction being a selected step length. After preprocessing the tomographic image with image smoothing and image enhancement, the image is stored in an image stack and sorted in a scanning order. A maximum brightness image and a three-dimensional height-encoded image are formed using computer image processing, and the height-encoded image contains three-dimensional height information of the surface morphology.

8. The method for measuring the amount of micro-oil on the surface of a steel plate according to claim 7, characterized in that: The maximum brightness image and three-dimensional height-encoded image are formed by computer image processing, and the primary / secondary morphological data are superimposed and analyzed to obtain the oil film coverage volume.

Images