High-temperature internal oxidation behavior of surface cracks in low alloy steel bloom

The oxidation behavior and mechanism near the crack of bloom was investigated by prefabricated crack and oxidation at high temperature (1000 – 1200 °C). The interface oxide layer composed of Fe2SiO4 and FeCr2O4 can prevent the steel matrix from being oxidized. However, the melting point of Fe2SiO4 is approximately 1170 °C, so the interface oxide layer is in a metastable state with the progress of high-temperature oxidation. At this time, the thickness of the internal oxidation spot layer in the steel matrix increases rapidly. As a result, internal oxidation mechanism of surface cracks at high temperature is clarified.