Abstract: According to the solubility product theory of second phase in austenite, Ostward ripening theory, grain size control theory and precipitation strengthening theory, the probability for formation of inclusions in austenite and the inclusion size control have been theoretically analyzed and calculated. The results show that the manganese sulfide inclusion can be controlled to precipitate in austenite with size less than 100 nm while it is difficult at present condition for the alumina inclusions to completely precipitate in solid iron. It is obtained by analysis on the probability of control to reheating austenite grain size and producing precipitate strengthening effect by inclusions in steel that the manganese sulfide precipitated in solid iron can effectively prohibit austenite grain growth in heating and provide somewhat of precipitation strengthening effect.

摘要： 根据奥氏体中第二相的固溶度积理论、Ostwald熟化理论、晶粒尺寸控制理论和沉淀强化理论， 对薄板坯连铸-连轧时钢中主要夹杂物在奥氏体中形成的可能性及其尺寸的控制进行了理论分析计算。结果 表明，硫化镐是有可能控制使之在奥氏体中以100nm以下尺寸沉淀析出；而氧化铝夹杂在目前条件下很难使 之完全在固态铁中析出。夹杂物在钢中控制再加热时奥氏体晶粒尺寸及产生沉淀强化效果的可能性的分析 表明，固态铁中析出的硫化锭可有效抑制均热态奥氏体晶粒粗化并产生微弱的沉淀强化效果。

关键词: 夹杂物, 尺寸控制, MnS, Al₂O₃ 奥氏体