Extreme removal of fine inclusions from 304 stainless steel via high-temperature supergravity fields

The extreme removal of SiO2 and MnO inclusions in 304 stainless steel in supergravity fields was investigated using the self-developed high-temperature supergravity equipment. The influence of gravity coefficient and separation time on the removal efficiency of inclusions was studied. After supergravity treatment, inclusions migrated to the top of the sample, forming large aggregates, while the lower part of the sample was significantly purified, appearing much cleaner than the raw material. At the gravity coefficient of 500 and separation time of 600 s, the total oxygen content at the bottom of the sample (position E) decreased from 240 ppm to 28 ppm, achieving a total oxygen removal rate of 88.33%. The volume fraction and number density of inclusions exhibited a gradient distribution along the supergravity direction, with values of 8.5% and 106 mm-2 at the top of the sample (position A) and only 0.06% and 22 mm-2 at the bottom.