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Production of most of the conventional steels involves melting, casting, hot-making and heat treatment. The microstructure of several of the high quality steels for instance high speed steels, tool steels, high temperature steels, wear resistant steels and others consist of martensitic, bainitic, feritic or austenitic matrix and different types of carbides. Carbides are phases in a microstructure which are assembled by carbon atoms and elements that form carbides (Fe, W, Mo, Cr, V etc.). Carbides play an important role in mechanical properties of steel such as hardness, wear resistance and temperature resistance. There is variety of different carbide types in steels depends on the steel composition and the rate of cooling. Eutectic carbides, specially the largest one are usually not desirable and are removed during hot-working process. Small-secondary type of carbides occurred during further heat-treatment of the steel. Carbides are usually designated by general formula MC, M2C, M6C, M7C3, M23C6 and so on, where M represents Fe, W, Mo, Cr, V with trace of other elements. During the steel-production process the carbides change significantly in terms of their distribution, quantity and size as well as their crystallographic type, all of which has a major effect on the steel’s properties. Major rule for obtaining the high quality steel is to have carbides as small as possible and homogenously distributed. The size of carbide precipitates are usually in a range of 10 to 200 nm. It is very important to be able to determine and analyse the different carbides and specially the small one. For this reason EBSD analysis combined by EDS analysis was applied. It was found that combining both analytic tools gave some promising results also for identification of small carbides. |