Influence of Multi-Step Heating Methods on Properties of Al–Si Coating Boron Steel Sheet

Abstract

In this study, the influence of the multi-step heating methods, such as two-step heating methods and three-step heating methods, on the properties of Al–Si coating boron steel sheet were evaluated by using the Gleeble-3500 thermal simulator. The evolution of microstructure and 3D surface topography of the Al–Si coating were also investigated. The results showed that the heating rates of 50 °C/s, named rapid heating, at the stage of 20–500 °C did not significantly influence the microstructure and 3D surface topography of the Al–Si coating in the two-step heating methods. The results also indicated that the volume fractions of Fe3Al2Si3 intermetallic compound, FeAl intermetallic compound and a-Fe phase in the Al–Si coating reduced by rapid heating at the stage of 700–930 °C in the three-step heating methods. The roughness of 3D surface topography of the Al–Si coating increased by rapid heating at the stage of 700–930 °C. Rapid heating at the stage of 700–930 °C had little influence on the porosity of the Al–Si coating. The results provided a theoretical basis for the popularization and application of rapid heating in the Al–Si coating boron steel sheet.