Study on the Removal of Oxide Scale Formed on 300 M Steel Special-Shaped Hot Forging Surfaces during Heating at Elevated Temperature by a High-Pressure Water Descaling Process.

Numerical simulations and experiments were utilized to study the removal of oxide scale formed on 300 M steel special-shaped hot forging surfaces during heating at elevated temperature by a high-pressure water descaling process. Specifically, the experimental setup of the special-shaped hot forging was designed and manufactured according to the descaling parameters and simulation results obtained from the hot rolling process. The force states of three typical hot forging surfaces impinged by high-pressure water jets were analyzed. Moreover, the mechanism of the high-pressure water descaling process was proposed based on the research results. The numerical simulations and experimental results revealed that the velocity distribution of the high-pressure water jets is relatively different in various areas of the special-shaped hot forging surfaces. Therefore, the descaling performance is synergistically influenced by the velocity of the high-pressure water jet and the shape of the special-shaped hot forging. Given a certain spray pressure, the value of impact force Fi plays a significant role in the descaling of the typical hot forging. The larger the value of Fi on the typical hot forging surface, the easier it is to remove the oxide scale, and vice versa. Accordingly, the difficulty of removing the oxide scale formed on the 300 M steel special-shaped hot forging surfaces during heating at elevated temperature by a high-pressure water descaling process is in the following order: plane surface < convex surface < concave surface. Additionally, only the inner-layer FeO of the oxide scale remained after the high-pressure water descaling process due to the appearance of FeO-FeSiO eutectic in the FeO layer.