Times of boost and diffusion stages in a vacuum furnace were empirically determined by an experimental heat treatment cycle carried out with similar loads. One advantage that vacuum furnaces provide is good repeatability of the process parameters, yielding predictable case hardening results. In this work, an algorithm is developed mathematically to determine the theoretical time of diffusion in a vacuum furnace (after the boost period) to obtain a final 0.8 percent C at the surface of carburized samples. Three batches of gas carburized samples, with different levels of surface carbon and case depths, were subjected to increasing diffusion temperatures in a vacuum furnace.
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