A Comparative Study of the Oxidation Behavior of Hot-Rolled Steel established from Medium and Thin Slabs oxidized in 20% H2O-N2 at 600-900°C

Abstract

This study focuses on the oxidation behavior of oxide scale on hot-rolled steel from a Thailand steel industry. Hot-rolled steel established from the medium and thin slabs was studied. The oxidation behavior was conducted in a horizontal furnace with 20%H2O-N2 to simulate steel oxidation during the hot rolling line. The scale was formed at a temperature range of 600-900°C for 30, 60, and 90 min. The scale morphology can be seen via Scanning Electron Microscope (SEM-EDS). The oxide phase was investigated via X-Ray Diffraction (XRD). The results show that iron oxides such as hematite (Fe2O3) and magnetite (Fe3O4) were produced on the studied steel. The oxidation behavior of the studied steel was followed by a parabolic law. The mass gain increased with increasing temperatures. The steel established from a medium slab exhibited a lower oxidation rate than the steel established from a thin slab. The reason for this could be the high amount of oxide containing silicon at the steel-scale interface, which promoted the oxidation resistance of the steel established from the medium slab. The influence of different slab types and its alloying elements was studied to comprehend the oxidation behavior. As a result, the alloying element in the hot-rolled steel was controlled in the design process.