Study And Application On The Key Techniques Of The Qantitative Metallographical Automatic Analysis System

Metal material occupies dominant position continuously in the material industry. Among the various methods of metal material analysis, metallographic analysis, because of its being direct-viewing, has always been a feasible and effective way of research and testing, which is widely applied in the field of Material Science and Engineering. Metallographic analysis is an important way for research of metal material. It has been depending on inspecting the image under microscope since long ago. It has subjectivity as it relies on the analyst's knowledge and experience.With the development of computer technology, many items of metallographic analysis can be accomplished by computer. Uses of computer technology will greatly decrease subjectivity, as well as the requirements for the technical staff's experience. Therefore, development of metallographic automation is the main tendency of metallographic analysis. Currently only a small fraction of metallographic testing can be done by computer automatically. The main research direction of this thesis is to further the improvement of automation and intelligence in metallographic analysis with computer application.This thesis discusses the primary principle and methods of testing in metallographic analysis, including analysis and rating of crystal degree, nonmetal inclusion, eutectic carbide, and automatic testing of depth of penetration layer, after introducing some basic concepts and principles.The method of automatic grading in grain size measurement is put forward based on the definition of grain size in the Chinese Standards. The method of using image processing techniques of dimension calibration, image binarization, noise elimination, intergranular extraction to count the crystals and then rank them is introduced. The difficulty of automatic crystal counting due to one identical intergranular shared by two adjacent grains is solved through turning one intergranular into two single-image-element intergranulars. The second-phases and impurities are removed through limiting the length of Freeman chain during crystals counting.On the basis of statistics, the transformation realization from qualitative description to quantitative description of inclusion rating in Chinese standard is put forward. Automatic classification and rating is completed with computer rating model of inclusion after the inclusion rating parameters are extracted with digital image processing.The method of establishing mathematics model of eutectic carbide rating with fuzzy mathematics is also provided.Wavelet shapes of carburize and nitriding is researched, and automatic testing of depth of penetration layer is resolved, based on the theory of wavelet multi-resolution.Finally, the structure and functional module of the software OpenPark is introduced, which has reference for the development of related software of image processing.