Abstract: The effect of oxygen content T [O] on distribution, size and morphology of sulfide inclusions in 160 mm × 160 mm cast billet of Y1215 free cutting steel and the deformation status of sulfide inclusions in hot rolling to φ8.0 mm coil are studied. The results show that with the increase of oxygen content, the size and distribution of sulfide inclusions in cast billets have no obvious difference; but the complex inclusions increase including MnS as core covered or adhered by MnO-SiO₂ and MnO-SiO₂-Al₂O₃ as core adhered by MnS. In the φ8.0 mm rolled coil rod, rod as T [O]0.0074%, the sulfide deformation in the wire rod is obvious, part of the sulfide is broken because of serious tensile deformation, the length-width ratio of sulfide is 23.2, as T[O] 0.0145%, the sulfide deformation along the rolling direction is small mainly in the spindle shape with length-width ratio3.4.For Y1215 free cutting steel, in order to obtain spherical or spindle sulfide inclusions, the T [0] in smelting steel can be controlled between 0 0095% and 0 0145%

Key words: Free Cutting Steel Y1215, Oxygen Content, Sulphide

摘要： 研究了T[O]0.0074%～0.0145%对Y1215易切削钢(/%:0.05～0.06C,0.008～0.010Si, 1.26～1.27Mn, 0.049～0.051P,0.37～0.39S)160 mm×160 mm铸坯中硫化物夹杂的分布、尺寸、形貌的影响和轧制Φ8.0 mm热轧盘条中硫化物的变形情况。结果表明：随着氧含量增加，铸坯中硫化物夹杂的尺寸和分布无明显区别，但复合夹杂物数量明显增多，复合型的夹杂物有以MnS为核心包裹或附着MnO-SiO2和以MnO-SiO₂-Al₂O₃为核心附着MnS夹杂物。在轧制Φ8.0 mm的盘条中，T [O]为0.0074%时，盘条中硫化物变形明显，部分硫化物由于拉伸变形严重而碎断，硫化物的长宽比为23.2, T [O]为0.0145%时，盘条中硫化物沿轧制方向变形小，主要以纺锤形为主，硫化物的长宽比为3.4。为获得球形或纺锤形的硫化物，冶炼时Y1215钢中的T[O]可控制在0.0095%～0.0145%。

关键词: Y1215易切削钢, 氧含量, 硫化物