The application of advanced oxide scale failure diagrams to curved surfaces during high-temperature processing: a case study of conveyance tube manufacturing

Conveyance tube manufacturing is an energy-intensive process which promotes rapid surface oxidation of curved surfaces. Previous works used computational, experimental, and theoretical techniques to assess oxidation of curved surfaces. Fast, flexible computational predictions of oxide thickness can provide the continuous data necessary to generate a spatiotemporal stress profile for application to the high-level Advanced Oxide Scale Failure Diagram (AOSFD) developed in this work. To demonstrate the application of the AOSFD to conveyance tube normalisation, the oxide states after induction vs. gas-barrel heating were compared. Induction heating technology is an example of a current technological development in high-temperature steel processing which offers improved operational control and suitability for decarbonised steel processing. Current frequency control during induction heating decreases the resultant strain magnitude in the oxide thereby eliminating the compressive failure modes observed during gas-barrel heating. Higher-than-typical temperatures result in an increased tensile strain component, increasing interfacial failure probability during induction heating. However, the advantages of induction heating technology, in terms of oxide failure management, can only be achieved with sufficient electromagnetic design controls. This conclusion agrees with purely temperature-based studies of oxide failure, but the AOSFD approach accommodates the mechanical and kinetic phenomena of the oxide by combining diffusion and fracture mechanics analyses into a single diagram which is quick and simple to apply to industrial contexts which demand oxidation control on curved surfaces