Examination of the adhesion of the scale formed on hot-rolled steel with different silicon content using a tensile test

In the hot-rolling process, steel was subjected to high temperatures which results in the formation of an oxide layer called scale. The oxide scale can be affected to the surface characteristic of the hot-rolled steel product. The scale must be completely removed from the surface of the steel before further processing. This research aimed to examine the adhesion behavior of scale on hot-rolled steel with different silicon contents (0.01, 0.12, 0.18, and 0.29 wt%) using a tensile testing machine with an observation setup. The results showed that the scale thickness decreased with increasing silicon content in the range of 9 mu m to 12 mu m. The scales were composed of hematite and magnetite. The results of the tensile test showed that the strain initiating the first spallation and the mechanical adhesion energy tend to increase with increasing silicon content. However, it decreased by 0.29 wt% Si hot-rolled steel. This result indicates that scale was difficult to remove after the hot rolling process for higher Si-containing steel.