A method for measuring the equiaxed crystallinity distribution along the width of a cast billet

Abstract

This invention discloses a method for measuring the width distribution of equiaxed crystal ratio in cast billets, belonging to the field of automation and image processing technology in iron and steel metallurgy. The method includes: obtaining an image of an equiaxed crystal sample; extracting the contour of the equiaxed crystal region of the equiaxed crystal sample; obtaining the pixel height and pixel width of the equiaxed crystal sample image; determining the number of equiaxed crystal region segments; dividing the equiaxed crystal sample into segments along the pixel width direction of the cast billet; determining the number of equiaxed crystal region contours of the equiaxed crystal sample; if only one equiaxed crystal region contour exists, executing the single equiaxed crystal region equiaxed crystal ratio distribution processing flow; otherwise, proceeding to the multi-equiaxed crystal region equiaxed crystal ratio distribution processing flow. This invention automatically completes equiaxed crystal region contour recognition, equiaxed crystal ratio calculation, equiaxed crystal region quantity detection, and the distribution of equiaxed crystal ratio in each region of the equiaxed crystal sample along the width direction of the cast billet, ultimately achieving the measurement and display of the equiaxed crystal ratio of the cast billet along the width direction.

Description

Technical Field

[0001] This invention belongs to the field of automation and image processing technology in iron and steel metallurgy, and more specifically, relates to a method for measuring the equiaxed crystal ratio distribution along the width of a cast billet. Background Technology

[0002] The solidification of a cast billet is a highly complex process involving the transformation from a liquid to a solid phase. It encompasses a series of intricate factors, including high temperature, convection diffusion, solute diffusion, and phase transformation, making direct observation and control of the solidification process difficult in practice. Currently, technicians primarily rely on metallographic experiments to detect the solidification microstructure of the billet and analyze the impact of different continuous casting process parameters on the equiaxed crystal ratio at the billet center, thereby optimizing the continuous casting process parameters.

[0003] There are two main methods for measuring equiaxed crystals: the thickness method and the area method. The thickness method measures the thickness of the equiaxed crystal region along the thickness direction of the equiaxed crystal sample. The percentage ratio of the equiaxed crystal thickness to the total thickness of the sample is the equiaxed crystal ratio. The area method calculates the area of ​​the equiaxed crystal region and the area of ​​the grain region, and the percentage ratio of the two areas is the equiaxed crystal ratio.

[0004] The existing method for delineating equiaxed crystal regions mainly relies on manual observation of grain distribution on the end face of equiaxed crystal samples. Grain boundaries are straightened, and equiaxed crystal regions are manually marked. The thickness method is generally used to calculate the equiaxed crystal ratio of the cast billet. However, this method still has the following problems:

[0005] 1. The equiaxed crystal region of the billet is manually divided, which has a large error. In addition, the thickness of the equiaxed crystal region is manually measured with a tape measure, which has low measurement accuracy, low efficiency and poor consistency of results.

[0006] 2. Manually measuring the thickness of the equiaxed crystal region in the 1 / 4, 1 / 2, and 3 / 4 width directions of the billet to calculate the equiaxed crystal ratio of the billet cannot accurately reflect the comprehensive performance of the equiaxed crystals in the billet;

[0007] 3. The distribution of equiaxed crystals in the billet is irregular, with multiple equiaxed crystal regions. Existing methods for measuring equiaxed crystals cannot accurately measure the equiaxed crystal ratio of the billet, nor can they detect the distribution characteristics of the equiaxed crystal ratio along the width direction of the billet. There is a lack of effective methods for multi-dimensional evaluation of the equiaxed crystal performance of the billet. Summary of the Invention

[0008] To address the aforementioned problems with existing manual measurements of equiaxed crystals in cast billets, and to improve the accuracy of equiaxed crystal detection, this paper introduces an evaluation method for the distribution of equiaxed crystals along the width of the cast billet. This method provides a measurement method for the width distribution of equiaxed crystal ratio in cast billets. Based on existing methods for detecting the area of ​​equiaxed crystal ratio in cast billets, this paper introduces image processing technology for equiaxed crystals in cast billets to automatically complete the contour recognition of equiaxed crystal regions, calculation of equiaxed crystal ratio, detection of the number of equiaxed crystal regions, and the distribution of equiaxed crystal ratio in each region of the equiaxed crystal sample along the width of the cast billet. Ultimately, this method achieves the measurement and display of the width-direction equiaxed crystal ratio of the cast billet.

[0009] To achieve the above objectives, the present invention provides a method for measuring the equiaxed grain ratio distribution along the width of a cast billet, comprising:

[0010] Obtain an image of the equiaxed crystal sample, extract the contour of the equiaxed crystal region from the image, and obtain the pixel height h of the equiaxed crystal sample image. P and pixel width w P ;

[0011] Determine the number of equiaxed crystal regions n s The image of the equiaxed crystal sample is divided into individual segmented images (imgs) along the pixel width direction of the cast billet. i The width is w s =w P / n s The pixel region is [(i-1)*w s :i*w s ,:],i=1,2,…,n s ;

[0012] Determine the number of equiaxed crystal region contours in the image of the equiaxed crystal sample. If only one equiaxed crystal region contour exists, then the number is determined based on the pixel height h. P Pixel width w P and w s Calculate each segmented image (imgs) using the area method. i The equiaxed crystallinity and the overall equiaxed crystallinity of the equiaxed crystal sample;

[0013] If there are multiple equiaxed crystal region contours, the coordinates of the minimum bounding rectangle of each equiaxed crystal region contour are obtained. The equiaxed crystal sample image is segmented along the height direction based on the coordinates of the horizontal slitting line. The equiaxed crystal sample segmented from the horizontal slitting line in the height direction is then averaged along the pixel width direction of the billet to obtain the equiaxed crystal ratio of the equiaxed crystal region and the overall equiaxed crystal ratio of the equiaxed crystal sample in each segmented image.

[0014] In some alternative implementations, if only one equiaxed crystal region contour exists, then the pixel height h is used as the basis for the determination. P Pixel width w P and w sCalculate each segmented image (imgs) using the area method. i The equiaxed crystallinity and the overall equiaxed crystallinity of the equiaxed crystal sample include:

[0015] Extracting single-block segmented images (imgs) i Equiaxial crystal region contour, based on pixel height h P Pixel width w P and w s Calculate each segmented image (imgs) using the area method. i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st ;

[0016] Draw each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st Distribution curve along the width of the billet.

[0017] In some optional implementations, if multiple equiaxed crystal region contours exist, the coordinates of the minimum bounding rectangle of each equiaxed crystal region contour are obtained. The equiaxed crystal sample image is then segmented along the height direction based on the horizontal slicing line coordinates. The equiaxed crystal sample segmented from the horizontal slicing line along the horizontal slicing line is then averaged along the pixel width direction of the cast billet to obtain the equiaxed crystal ratio of the equiaxed crystal region and the overall equiaxed crystal ratio of the equiaxed crystal sample for each segmented image, including:

[0018] Obtain the coordinates of the minimum bounding rectangle of the contour of each equiaxed crystal region [x] j :x j +w j ,y j :y j +h j ] Calculate the coordinates of the horizontal tangent line he j ;

[0019] From the horizontal tangent line coordinates he j At this point, the image of the equiaxed crystal sample is divided into n sections along the height direction. e One image, a single-block segmented image (imgh) j The pixel region is [:,he j-1 :he j ], j = 1, 2, ..., n e ;

[0020] The equiaxed crystal sample imgh after being cut at the horizontal slitting line in the height direction j Divide the billet into n equal parts along the pixel width direction. s One image, a single-block segmented image (imgd) j iThe pixel region is [(i-1)*w s :i*w s ,he j-1 :he j ];

[0021] Extracting single-block segmented image imgd j i Contours of equiaxed crystal regions, calculate the imgd of each sliced ​​image. j i Equiaxed crystallite region equiaxed crystallite ratio pd j i ;

[0022] Calculate the image (imgh) for each equiaxed crystal region. j Equiaxial crystallinity pdh j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The overall equiaxed crystal ratio p of the equiaxed crystal sample dt ;

[0023] Draw each segmented image imgd j i Equiaxed crystallite region equiaxed crystallite ratio pd j i The equiaxed crystal ratio pdh of each equiaxed crystal region j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The total equiaxed crystal ratio p of the equiaxed crystal sample dt Distribution curve along the width of the billet.

[0024] In some alternative implementations, the calculation of each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st ,include:

[0025] Get each segmented image (imgs) i equiaxed crystal region contour pixel area a i ;

[0026] Each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i for:

[0027]

[0028] The overall equiaxed crystal ratio p of the equiaxed crystal specimen st for:

[0029]

[0030] In some alternative implementations, the drawing of each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st The distribution curve along the width of the cast billet includes:

[0031] Image fragments (imgs) i Right width coordinate i*w s The horizontal axis variable represents each segmented image (imgs). i Equiaxed crystal ratio ps in equiaxed crystal region i Output variables for the ordinate and display each ps. i Percentage values, plot each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i Distribution curve along the width of the cast billet;

[0032] Image fragments (imgs) i Right width coordinate i*w s The x-axis variable represents the overall equiaxed crystal ratio p of the equiaxed crystal samples. st As the output variable for the ordinate, draw a horizontal line and display p. st Percentage values ​​are used to visually display each segmented image (imgs). i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st The differences.

[0033] In some alternative implementations, the calculation of the horizontal tangent line coordinates he j ,include:

[0034] Horizontal tangent line coordinates he j for:

[0035]

[0036] In some alternative implementations, the calculation of each sliced ​​image imgd j i Equiaxed crystallite region equiaxed crystallite ratio pd j i ,include:

[0037] Get each sliced ​​image imgd j i Equiaxed crystal region contour pixel area adj i ;

[0038] Each segmented image (imgd) j i Equiaxed crystallite region equiaxed crystallite ratio pd j i for:

[0039]

[0040] In some alternative implementations, the calculation of each equiaxed crystal region image (imgh) j Equiaxial crystallinity pdh j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The overall equiaxed crystal ratio p of the equiaxed crystal sample dt ,include:

[0041] Image of each equiaxed crystal region (imgh) j Equiaxial crystallinity pdh j for:

[0042]

[0043] Pixel region [(i-1)*w s :i*w s ,0:h p Equiaxed crystal ratio pdt in the equiaxed crystal region i for:

[0044]

[0045] The overall equiaxed crystal ratio p of the equiaxed crystal specimen dt for:

[0046]

[0047] In some alternative implementations, the drawing of each segmented image imgd j i Equiaxed crystallite region equiaxed crystallite ratio pd j i The equiaxed crystal ratio pdh of each equiaxed crystal region j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The total equiaxed crystal ratio p of the equiaxed crystal sample dt The distribution curve along the width of the cast billet includes:

[0048] Using segmented image imgd j i Right width coordinate i*w s The x-axis variable is represented by the image ID (imgd). j i Equiaxed crystallite region equiaxed crystallite ratio pd j i Output variables for the ordinate and display each pd. j i Percentage values, plot each segmented image (imgd) j i Equiaxed crystallinity pd j i Distribution curve along the width of the cast billet;

[0049] Using segmented image imgd j i Right width coordinate i*w s The x-axis variable represents the equiaxed crystallinity pdh of each equiaxed crystal region. j As the output variable for the ordinate, draw a horizontal line to display pdh j Percentage value;

[0050] Using segmented image imgd j i Right width coordinate i*w s The x-coordinate variable represents the pixel region [(i-1)*w]. s :i*w s ,0:h p The total equiaxed crystallinity pdt i Output variables for the ordinate and display each pdt. i Percentage value, calculate the region [(i-1)*w s :i*w s ,0:h p [All segmented images in imgd] j i The sum of equiaxed crystallinity, i.e., the region [(i-1)*w s :i*w s ,0:h p The equiaxed crystallinity of all equiaxed crystal regions within the region is plotted in the region [(i-1)*w]. s :i*w s ,0:h p The total equiaxed crystallinity pdt i Distribution curve along the width of the cast billet;

[0051] Using segmented image imgd j i Right width coordinate i*w sThe x-axis variable represents the total equiaxed crystal ratio p of the equiaxed crystal sample. dt As the output variable for the ordinate, draw a horizontal line and display p. dt Percentage value.

[0052] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0053] 1. This invention can automatically extract the contour and quantity of equiaxed crystal regions in an equiaxed crystal sample, realize the horizontal division of different equiaxed crystal regions in the equiaxed crystal sample, and use the area method to realize the automatic calculation of the equiaxed crystal ratio of each equiaxed crystal region.

[0054] 2. This invention achieves the measurement of equiaxed crystal ratio along the pixel width direction of the cast billet by averaging the equiaxed crystal sample along the average width direction of the cast billet and combining the horizontal division of different equiaxed crystal regions of the equiaxed crystal sample.

[0055] 3. This invention plots the distribution curves of the equiaxed crystal ratio of each equiaxed crystal region and the equiaxed crystal ratio of the equiaxed crystal sample along the pixel width direction of the billet, which can conveniently and intuitively display the magnitude of the equiaxed crystal ratio at different positions of the billet, and realize the measurement and display of the equiaxed crystal ratio distribution performance of the billet. Attached Figure Description

[0056] Figure 1 This is a flowchart of the method for measuring the equiaxed grain ratio distribution along the width of a cast billet provided in an embodiment of the present invention;

[0057] Figure 2 These are classification images of equiaxed crystal samples from Embodiment 1 of the present invention;

[0058] Figure 3 This is a contour diagram of the equiaxed crystal region of Embodiment 1 of the present invention;

[0059] Figure 4 This is a segmentation diagram of the equiaxed crystal region outline along the pixel width direction of the cast billet in Embodiment 1 of the present invention;

[0060] Figure 5 This is a graph showing the equiaxed crystal ratio distribution of the equiaxed crystal sample in Example 1 of the present invention;

[0061] Figure 6 These are classification images of equiaxed crystal samples from Embodiment 2 of the present invention;

[0062] Figure 7 This is a contour diagram of the equiaxed crystal region in Embodiment 2 of the present invention;

[0063] Figure 8 This is a schematic diagram of the contour segmentation of the equiaxed crystal region in Embodiment 2 of the present invention;

[0064] Figure 9 This is a contour diagram of the equiaxed crystal region 2 after horizontal segmentation of the equiaxed crystal region contour in Embodiment 2 of the present invention;

[0065] Figure 10 This is a segmentation diagram of the contour of the equiaxed crystal region 2 along the pixel width direction of the casting in Embodiment 2 of the present invention;

[0066] Figure 11 This is a contour diagram of the equiaxed crystal region 1 after horizontal segmentation of the equiaxed crystal region contour in Embodiment 2 of the present invention;

[0067] Figure 12 This is a segmentation diagram of the contour of the equiaxed crystal region 1 along the pixel width direction of the cast billet in Embodiment 2 of the present invention;

[0068] Figure 13 This is a graph showing the equiaxed crystal ratio distribution of the equiaxed crystal sample in Example 2 of the present invention. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0070] The following is in conjunction with the appendix Figures 1-13 The present invention will be further illustrated by the following examples:

[0071] This disclosure provides a method for measuring the equiaxed crystal ratio distribution along the width of a cast billet. Figure 1 This is a flowchart illustrating a method for measuring the equiaxed grain ratio distribution along the width of a cast billet, as provided in the embodiment. The method includes the following steps:

[0072] In step 101, the image of the equiaxed crystal sample is read, the contour of the equiaxed crystal region of the equiaxed crystal sample is extracted, and the pixel height h of the equiaxed crystal sample image is obtained. P and pixel width w P ;

[0073] In step 102, the number of equiaxed crystal regions n is determined. s The image of the equiaxed crystal sample is divided into segments along the pixel width direction of the cast billet, and the individual segmented images are shown in images. i The width is w s =w P / n s The pixel region is [(i-1)*w s :i*w s ,:],i=1,2,…,n s ;

[0074] In step 103, the number of equiaxed crystal region contours in the equiaxed crystal sample image is determined. If there is only one equiaxed crystal region contour, step 104 is executed; otherwise, the process proceeds to step 204.

[0075] In step 104, extract the segmented images (imgs) of each block. i The contour of the equiaxed crystal region is obtained by automatically calculating the imgs of each segmented image, referring to formulas (1) and (2). i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st .

[0076] In step 105, each segmented image (imgs) is drawn. i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st Distribution curve along the width of the billet.

[0077] In step 204, the coordinates of the minimum bounding rectangle of the contour of each equiaxed crystal region are obtained [x]. j :x j +w j ,y j :y j +h j Referring to formula (3), the coordinates of the horizontal tangent line he are automatically calculated. j .

[0078] Where, x j w j y j h j Let x and x represent the pixel coordinates of the minimum bounding rectangle, respectively. j y j These are the pixel width and pixel height coordinates of the starting vertex (top left endpoint) of the smallest bounding rectangle; w j h j These are the minimum bounding rectangle's pixel width and pixel height, respectively.

[0079] In step 205, the horizontal tangent line coordinates he are... j At this point, the image of the equiaxed crystal sample is divided into n sections along the height direction. e One image, a single-block segmented image (imgh) j The pixel region is [:,he j-1 :he j ], j = 1, 2, ..., n e .

[0080] In step 206, the horizontally segmented equiaxed crystal sample image is displayed.j Divide the billet into n equal parts along the pixel width direction. s One image, a single-block segmented image (imgd) j i The pixel region is [(i-1)*w s :i*w s ,he j-1 :he j ].

[0081] In step 207, the segmented image imgd is extracted. j i The contour of the equiaxed crystal region is automatically calculated for each segmented image (imgd) according to formula (4). j i Equiaxed crystallite region equiaxed crystallite ratio pd j i .

[0082] In step 208, referring to formulas (5), (6), and (7), the image imgh of each equiaxed crystal region is calculated respectively. j Equiaxial crystallinity pdh j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The overall equiaxed crystal ratio p of the equiaxed crystal sample dt .

[0083] In step 209, each segmented image (imgd) is plotted. j i Equiaxed crystallite region equiaxed crystallite ratio pd j i Image of each equiaxed crystal region (imgh) j Equiaxial crystallinity pdh j Pixel region [(i-1)*w s :i*w s ,0:h p The total equiaxed crystallinity pdt i The overall equiaxed crystal ratio p of the equiaxed crystal sample dt Distribution curve along the width of the billet.

[0084] The following is combined with Figures 2-5 The following describes a specific embodiment 1 provided by the present invention:

[0085] like Figure 2 As shown, the classification image of the equiaxed crystal sample is read, and the contour of the equiaxed crystal region of the equiaxed crystal sample is extracted, as follows. Figure 3 As shown, the number n of equiaxed crystal regions in the equiaxed crystal sample is obtained. e=1, pixel height h of the equiaxed crystal sample image P =1877, pixel width w P =3105.

[0086] Determine the number of equiaxed crystal regions n s =20, the image of the equiaxed crystal sample is evenly divided along the pixel width direction of the cast billet, such as Figure 4 As shown, the single-block segmented image (imgs) i The width is w s =155, the pixel area is [(i-1)*155:i*155,:].

[0087] Extracting single-block segmented images (imgs) i The contour of the equiaxed crystal region is obtained by automatically calculating the imgs of each segmented image, referring to formulas (1) and (2). i Equiaxed crystal ratio ps in equiaxed crystal region i =[0.0,0.0,42.09%,76.58%,77.36%,77.24%,78.71%,76.98%,77.99%,78.26%,78.12%,78.31%,78.22%,80.21%,80.47%,79.11%,78.6%,78.24%,79.8%,78.3%], Overall equiaxed crystal ratio p of equiaxed crystal samples st =68.62%.

[0088] Draw each segmented image (imgs) i Equiaxed crystal ratio ps in equiaxed crystal region i The overall equiaxed crystal ratio p of the equiaxed crystal sample st Distribution curve along the width of the cast billet, such as Figure 5 As shown.

[0089] The following is combined with Figures 6-13 The following describes a specific embodiment 2 provided by the present invention:

[0090] Read the classification image of the equiaxed crystal sample, such as Figure 6 As shown, the contour of the equiaxed crystal region of the equiaxed crystal sample is extracted, as follows. Figure 7 As shown, the number n of equiaxed crystal regions in the equiaxed crystal sample is obtained. e =2, pixel height h of equiaxed crystal sample image P =1873, pixel width w P =3043.

[0091] Determine the number of equiaxed crystal regions n s =20, the image of the equiaxed crystal sample is evenly divided along the pixel width direction of the cast billet, and the single segmented image is shown in imgs. i The width is w s=152, the pixel area is [(i-1)*152:i*152,:].

[0092] Obtain the coordinates of the minimum bounding rectangle of equiaxed crystal region 1 [398:3040,878:1623] and the minimum bounding rectangle of equiaxed crystal region 2 [377:3038,256:717]. Refer to formula (3) to automatically calculate the coordinates of the horizontal tangent line he. j =798.

[0093] Refer to the cutting diagram Figure 8 The coordinates of the horizontally tangent line are he. j At position = 798, the image of the equiaxed crystal sample is divided into two images along the height direction. The image of the equiaxed crystal region 1 (imgh0) is shown in the following diagram. Figure 11 As shown, the image image of equiaxed crystal region 2 (imgh1 segmentation diagram) is as follows: Figure 9 As shown.

[0094] The equiaxed crystal region 1 image imgh0 and equiaxed crystal region 2 image imgh1, after being segmented from the horizontal slicing line along the height direction of the image, are averaged into 20 images along the pixel width direction of the cast billet, as follows: Figure 12 , Figure 10 As shown, the single-block segmented image imgd 0 i The pixel region is [(i-1)*152:i*152,1873:798], and the image is segmented into a single block, imgd. 1 i The pixel region is [(i-1)*152:i*152,0:798].

[0095] Extracting single-block segmented image imgd 0 i The contour of the equiaxed crystal region is automatically calculated for each segmented image (imgd) according to formula (4). 0 i Equiaxed crystallite region equiaxed crystallite ratio pd 0 i = [0.0,0.0,2.11%,13.05%,21.44%,27.14%,29.46%,30.07%,32.15%,32.38%,30.76%,32.78%,34.77%,34.67%,33.84%,35.63%,37.27%,36.04%,35.34%,34.16%], which is the equiaxed crystal ratio of the image segmented along the width direction of the equiaxed crystal region 1.

[0096] Extracting single-block segmented image imgd 1 i The contour of the equiaxed crystal region is automatically calculated for each segmented image (imgd) according to formula (4).1 i Equiaxed crystallite region equiaxed crystallite ratio pd 1 i = [0.0,0.0,2.69%,13.55%,16.7%,17.31%,15.73%,13.21%,13.88%,11.52%,13.06%,18.55%,19.19%,17.39%,16.68%,16.16%,18.34%,19.4%,16.03%,17.32%], which is the equiaxed crystal ratio of the image segmented along the width direction of the equiaxed crystal region 2.

[0097] Referring to formula (5), the equiaxed crystal ratio pdh0 of image imgh0 in equiaxed crystal region 1 is calculated to be 26.63%, and the equiaxed crystal ratio pdh1 of image imgh1 in equiaxed crystal region 2 is calculated to be 13.82%.

[0098] Referring to formula (6), the pixel region [(i-1)*152:i*152,0:h] p The total equiaxed crystallinity pdt i = [0.0,0.0,4.80%,26.60%,38.14%,44.45%,45.19%,43.28%,46.03%,43.90%,43.82%,51.33%,53.96%,52.06%,50.52%,51.79%,55.61%,55.44%,51.37%,51.48%], which is the sum of the equiaxed crystal ratios of the equiaxed crystal region 1 and equiaxed crystal region 2 in the image segmented along the width direction of the billet.

[0099] Calculate the overall equiaxed crystal ratio p of the equiaxed crystal sample according to formula (7). dt =40.45%, which is the sum of the equiaxed crystal ratio pdh0 of image imgh0 in equiaxed crystal region 1 and the equiaxed crystal ratio pdh1 of image imgh1 in equiaxed crystal region 2.

[0100] Draw each segmented image imgd j i Equiaxed crystal ratio (pd) in equiaxed crystal regions 0 i ,pd 1 i Image of each equiaxed crystal region (imgh) j The equiaxed crystal ratios (pdh0, pdh1), the total equiaxed crystal ratio pdt of the equiaxed crystal region 1 and equiaxed crystal region 2 segmented along the width of the billet i The overall equiaxed crystal ratio p of the equiaxed crystal sample dt Distribution curve along the width of the cast billet, such as Figure 13 As shown.

[0101] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0102] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for measuring the equiaxed grain ratio distribution along the width of a cast billet, characterized in that, including: Obtain an image of the equiaxed crystal sample, extract the contour of the equiaxed crystal region from the image, and obtain the pixel height of the equiaxed crystal sample image. h P and pixel width w P ; Determine the number of equiaxed crystal regions to be divided n s The image of the equiaxed crystal sample is divided into individual segmented images by dividing it into equal parts along the pixel width direction of the cast billet. imgs i The width is w s = w P / n s Pixel area is , i =1,2,…, n s ; Determine the number of equiaxed crystal region contours in the image of the equiaxed crystal sample. If only one equiaxed crystal region contour exists, extract the single-block segmented image. imgs i Equiaxial crystal region contour, based on pixel height h P Pixel width w P and w s Calculate each segmented image using the area method imgs i Equiaxed crystal ratio in equiaxed crystal region ps i The overall equiaxed crystal ratio of equiaxed crystal samples p st Draw each segmented image imgs i Equiaxed crystal ratio in equiaxed crystal region ps i The overall equiaxed crystal ratio of equiaxed crystal samples p st Distribution curve along the width of the cast billet; If multiple equiaxed crystal region contours exist, then obtain the coordinates of the minimum bounding rectangle of each equiaxed crystal region contour. x j : x j + w j , y j : y j + h j ] Calculate the coordinates of the horizontal tangent line he j , x j , y j These are the pixel width and pixel height coordinates of the starting vertex of the smallest bounding rectangle, respectively. w j , h j These are the minimum bounding rectangle's pixel width and pixel height; the coordinates of the horizontally tangent line. he j At this point, the image of the equiaxed crystal sample is divided along the height direction into... n e One image, a single-block segmented image imgh j The pixel region is [:, he j-1 : he j ], j =1,2,…, n e ; Equiaxed crystal specimens cut from the horizontal cleavage line along the height direction imgh j Divide the billet into pixels of equal width along the direction of the pixel width. n s One image, a single-block segmented image imgd j i The pixel area is Extracting single-block segmented images imgd j i Contour of equiaxed crystal regions, calculate each slicing image imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i ; Calculate the image of each equiaxed crystal region imgh j Equiaxial crystallinity pdh j Pixel area Internal total equiaxed crystallinity pdt i The overall equiaxed crystal ratio of equiaxed crystal samples p dt Draw each segmented image imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i Equiaxed crystallinity of each equiaxed crystal region pdh j Pixel area Internal total equiaxed crystallinity pdt i Total equiaxed crystal ratio of equiaxed crystal samples p dt Distribution curve along the width of the billet.

2. The method according to claim 1, characterized in that, The calculation of each segmented image imgs i Equiaxed crystal ratio in equiaxed crystal region ps i The overall equiaxed crystal ratio of equiaxed crystal samples p st ,include: Get each segmented image imgs i equiaxed crystal region contour pixel area a i ; Depend on Get each segmented image imgs i Equiaxed crystal ratio in equiaxed crystal region ps i ; Depend on Calculate the overall equiaxed crystal ratio of the equiaxed crystal sample p st .

3. The method according to claim 2, characterized in that, The drawing of each segmented image imgs i Equiaxed crystal ratio in equiaxed crystal region ps i The overall equiaxed crystal ratio of equiaxed crystal samples p st The distribution curve along the width of the cast billet includes: Image segmented by single block imgs i Right width coordinates The x-axis variable represents each segmented image. imgs i Equiaxed crystal ratio in equiaxed crystal region ps i Output variables for the y-axis and display each one. ps i Percentage values, plot each segmented image imgs i Equiaxed crystal ratio in equiaxed crystal region ps i Distribution curve along the width of the cast billet; Image segmented by single block imgs i Right width coordinates The x-axis variable represents the overall equiaxed crystallinity of the equiaxed crystal sample. p st Output the variable for the ordinate, draw a horizontal line, and display. p st Percentage value.

4. The method according to claim 1, characterized in that, Depend on Calculate the coordinates of the horizontal tangent line he j .

5. The method according to claim 4, characterized in that, The calculation of each sliced ​​image imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i ,include: Get each segmented image imgd j i equiaxed crystal region contour pixel area ad j i ; Depend on Calculate each sliced ​​image imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i .

6. The method according to claim 5, characterized in that, The calculation of each equiaxed crystal region image imgh j Equiaxial crystallinity pdh j Pixel area Internal total equiaxed crystallinity pdt i The overall equiaxed crystal ratio of equiaxed crystal samples p dt ,include: Depend on Calculate the image of each equiaxed crystal region imgh j Equiaxial crystallinity pdh j ; Depend on Calculate pixel region Equiaxed crystallinity in the inner equiaxed crystal region pdt i ; Depend on Calculate the overall equiaxed crystal ratio of the equiaxed crystal sample p dt .

7. The method according to claim 6, characterized in that, The drawing of each segmented image imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i Equiaxed crystallinity in each equiaxed crystal region pdh j Pixel area Internal total equiaxed crystallinity pdt i Total equiaxed crystal ratio of equiaxed crystal samples p dt Distribution curve along the width of the cast billet, including: To segment the image imgd j i Right width coordinates The x-axis variable represents each segmented image. imgd j i Equiaxed crystal ratio in equiaxed crystal region pd j i Output variables for the y-axis and display each one. pd j i Percentage values, plot each segmented image imgd j i Equiaxial crystallinity pd j i Distribution curve along the width of the cast billet; To segment the image imgd j i Right width coordinates The x-axis variable represents the equiaxed crystallinity of each equiaxed crystal region. pdh j Output the variable for the ordinate, draw a horizontal line, and display. pdh j Percentage value; To segment the image imgd j i Right width coordinates The x-axis variable represents the pixel region. Internal total equiaxed crystallinity pdt i Output variables for the y-axis and display each one. pdt i Percentage value, calculate the region All segmented images imgd j i The sum of equiaxed crystallinity, i.e., the region The equiaxed crystallinity of all equiaxed crystal regions within the plotted area. Internal total equiaxed crystallinity pdt i Distribution curve along the width of the cast billet; To segment the image imgd j i Right width coordinates The x-axis variable represents the total equiaxed crystal ratio of the equiaxed crystal sample. p dt Output the variable for the ordinate, draw a horizontal line, and display. p dt Percentage value.

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