Decarburization represents one of the key challenges in the heat treatment of steels, as the reduction of carbon content in the surface layers leads to a deterioration of mechanical properties.
The aim of this thesis was to demonstrate a method for calculating the thickness of the decarburized layer on the surface that must be removed after heat treatment in order to eliminate the undesirable properties. Using geometric relationships, an equation was determine to calculate the depth of decarburization at the edge of the specimen, where the effect is greater. With the help of equations used to determine decarburization on a flat surface, it is therefore possible to calculate the actual amount of material that must be removed to eliminate decarburization at the specimen edges as well. These equations can simplify work in industrial practice, as analysis can be performed without the need for sample preparation and metallographic examination.
In the experimental part, samples of three different steels were annealed at selected temperatures and times. After annealing, the samples were metallographically prepared, and the decarburization on their surfaces was examined using a digital microscope. The depth of the decarburized layer was measured both on the flat surface and at the specimen edge, where the decarburization is greater. Three models with different radii of curvature were proposed. Comparison between the calculated and measured data showed which model better describes the actual shape of the decarburized layer. The goal of the thesis was achieved, as the equation that enables the calculation of the actual depth of the decarburized material that need to be removed, including edges, was determined.
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