Method for rapidly measuring and finely classifying full-form crystal grains of steel material

Abstract

The invention discloses a method for rapidly measuring and finely classifying full-form crystal grains of a steel material. The method comprises the following steps: performing the operations of filtering, denoising, gray level correcting and binary segmentation treatment on an original image in sequence, and reducing a target crystal grain binary image; setting a scale for the reduced image, performing area calibration on target crystal grains respectively, and respectively extracting form characteristic parameters of each target crystal grain, wherein the form characteristic parameters include the area, the circumference, the grain size, the length-width ratio, the circularity degree, the form coefficient and the transgranular polar angle; distinguishing equiaxial crystal grains from non-equiaxial crystal grains according to a primary threshold of the circularity degree and a primary threshold of the form coefficient; distinguishing circular-like and polygon crystal grains from the equiaxial crystal grains according to a secondary threshold of the circularity degree and a secondary threshold of the form coefficient; and identifying strip-like and strip crystal grains and thick needle and small needle shaped crystal grains from the non-equiaxial crystal grains according to the length-width ratio and primary and secondary thresholds of the transgranular polar angle. The method is high in measurement precision, and the efficient and precise method is provided for rapid and fine microanalysis on the full-form crystal grains of the steel material.

Description

technical field [0001] The invention relates to the field of metallographic analysis of full-form grains in the microstructure of iron and steel materials, in particular to a rapid measurement and fine classification method for full-form grains of steel materials. Background technique [0002] With the rapid development of iron and steel material technology, the research and development of various steel materials has gradually been established on the basis of the quantitative relationship between composition, structure and performance, which means that for steel materials, the microstructure can be controlled through preparation and various subsequent processes to obtain the desired performance. Quantitative metallographic analysis is an important method to study the relationship between the composition, structure, process and performance of metal materials. Through quantitative analysis of the metallographic structure of various steel materials, a quantitative relationship ...

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Problems solved by technology

The main disadvantage of the above two methods is that only the grain size can be measured and only the average particle size can be obtained, which means that the particle size cannot be classified, let alone the characterization and classification of the grain shape, and the particle size classification The work needs to be realized by additional manual mode at a later stage

In addition, neither of these two methods can solve the common problems of missing grain boundaries and intragranular holes in metallographic images. The missing grain boundaries and intragranular holes must be connected, restored and filled by manual mode before the grain measurement can be carried out. Therefore, the manual mode will inevitably lead to problems such as low accuracy of measurement results and too long time-consuming, making the accurate measurement and classification of material grains become the bottleneck of new material research and development.

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