Abstract: The bearing steel GCrl5 in EAF tapping is pre-deoxidized by specialty refining slag and Al to control the Al content 0. 03% ~0. 06% in liquid, and the ingredient of LF refining slag is (/% ) 53 ~ 58CaO, 6 ~ 16SiO₂, 15 ~30Al₂O₃, 3~10 MgO, (FeO + MnO). The inclusions in 320 mm x 480 mm casting bloom and hot-rolled Φ45 mm round bar are analyzed by using auto scanning electron microscope ASPEX. Results show that the oxide inclusions in casting bloom and round bar of bearing steel GCr15 are magnesia alumina spinel or calcium aluminate, and the amount of oxide inclusions at edge of bloom and round bar is more than that at center, and the larger than 10μm inclusions are globular calcium aluminate or calcium aluminate-magnesia alumina spinel compound inclusion ； the non-oxide inclusions in bloom and round bar are mainly MnS, TiN and cladding inclusions-magnesia alumina spinel covered by MnS, TiN or CaS, and calcium aluminate covered by CaS. It is obtained by using Factsage calculation that MnS and TiN precipitate during solidification process and large amounts precipitate respectively at solid fraction fs being more than 0. 9 and 0. 6； there is large amount CaS in liquid at steelmaking temperature 1 600℃, minor precipitates during liquid cooling process and tiny minority precipitates during solidification process.

摘要： 轴承钢GCr15 EAF出钢用专用精炼渣和Al预脱氧、钢中Al含量为0.03%0.06%,LF精炼渣为/%:53~58CaO,6~16SiO₂,15~30Al₂O₃,3~10MgO,≤1（FeO+MnO）。利用自动扫描电镜ASPEX分析了320mm×480 mm铸坯和Φ45 mm热轧圆钢的夹杂物。结果表明,GCr15轴承钢铸坯和圆钢中的氧化物夹杂为镁铝尖晶石或钙铝酸盐,铸坯和圆钢边部的氧化物夹杂数量要大于中心,大于10μm夹杂物为球状钙铝酸盐或钙铝酸盐与镁铝尖晶石复合氧化物夹杂;铸坯和圆钢中非氧化物类夹杂主要有MnS、TiN和包裹型夹杂物MnS、TiN和CaS包裹镁铝尖晶石以及CaS包裹钙铝酸盐。利用Factsage计算得出,MnS和TiN在凝固过程中析出,并分别在固相率fs为0.9和0.6之后大量形成。CaS在炼钢温度下（1 600℃）就大量存在,在钢液冷却过程中少量析出,极少量在之后的凝固过程中形成。

关键词: 100 t EAF-LF-VD-CC流程, GCr15轴承钢, 320 mm x480 mm铸坯, , Φ45 mm圆钢, 夹杂物, ASPEX