An Empirical Model for Carbon Diffusion in Austenite Incorporating Alloying Element Effects

The diffusion of carbon in austenite is important to the design and implementation of many steel heat-treating processes. The present study proposes a simple and computationally efficient equation for the diffusion of carbon in austenite for iron-carbon alloys, as well as for steels alloyed with a variety of elements. The proposed empirical model provides a pragmatic engineering approach to this important diffusion process. The model is shown to better match the carbon diffusion profiles of several carburized steel alloys, as compared to other equations that have been reported in the literature. These other equations were primarily obtained from experiments on iron-carbon alloys, and it is not surprising that they are less accurate when compared to the proposed equation that takes the full range of alloy compositions into account.