고온 피어싱 공정 초기 산화층은 다층으로 형성되어 있으며, 약 312µm 두께의 전체적으로 균일한 산화층이 관찰되었다.
At the beginning of the high-temperature piercing process, the oxide layer was formed in multiple layers, and an overall uniform oxide layer with a thickness of about 312 µm was observed.