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The majority of highly stressed steel components are manufactured through hot forming due to the increase in strength and toughness resulting from the formed fine-grained microstructure. Additionally, the alloying element manganese promotes high strength and hardness. Sulfur is added in order to ensure an improved machinability in the post-machining steps. However, at high temperatures present during hot forming, manganese and sulfur tend to form non-metallic inclusions consisting of manganese sulphide (MnS). These inclusions act as mechanical weak points in the steel matrix and can lead to an early failure of components. In order to accurately model the hot forming process and predict the final properties of the component, the behaviour of the steel matrix as well as the MnS-inclusions is required. In this paper, the focus lies in the characterisation of the flow behaviour of two commonly used steel alloys containing varying contents of manganese and sulfur, 1.7139 (16MnCrS5) and 1.1303 (38MnVS6). Cylindric upsetting tests are conducted at different strain rates as well as temperatures typical for hot forming to determine the resulting flow curves which are then modelled with the Hensel-Spittel approach. These are used for the numerical simulation of the experiments based on the finite element method for validation. For this, a mesh study is conducted first, and the resulting force-displacement curves are compared to the experimental data.
Keywords: Manganese steel, manganese sulphide, flow curves, finite element method© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.