Abrasive flow machining of specimens of cast billets from austenomartensitic steel with high-viscosity media

The paper presents the results of research on abrasive flow machining of removable specimens of cast billets made of austenomartensitic steel placed in a simulator of a closed curvilinear channel. The change in the roughness and micro-hardness of the surface of the samples was evaluated. There are two stages of machining. At the first stage of machining, most of the casting skin is removed. At the second stage, the casting skin is removed completely and the base metal layer is removed. It was established that the main mechanism for removing material from the surface of a cast billet is microcutting at the level of elementary real areas of contact of individual grain micro-protrusions. According to the results of the experiments, it is recommended to use abrasive flow machining with highly viscous medium to improve the roughness and increase the micro-hardness of the inner surfaces of the closed channels of cast billets.