Using computer vision to analyse fracture strains of oxide scale layers on a macro level

Abstract

Abstract. Hot forging has established itself as an efficient process for the manufacture of highly stressed components. The high semi-finished product temperatures significantly increase the deformation capacity and enable the production of complex geometries. However, high semi-finished product temperatures of up to 1250 °C also lead to increased oxide scale formation. Therefore, oxide scale plays an important role in the context of hot forming processes. Due to the contrasting properties between steel substrates and oxide scale, the appearance of oxide scale affects numerous influencing factors, such as changed friction conditions or thermophysical properties. With increasing interest in numerical process prediction arises the demand to take into account the behaviour of oxide scale in finite-element simulations. In addition to the numerical mapping of the crack behaviour, the challenge in mapping the oxide scale is to determine suitable parameters for describing the failure behaviour. Therefore, this work focuses on a novel procedure to characterise the failure of oxide scale under process relevant conditions of hot forging.