板坯结晶器喂稀土对30CrMnMo钢夹杂物和低温韧性的影响

在300 mm×1950 mm板坯结晶器宽面中心两侧500 mm处向30CrMnMo钢(/%:0.31C,0.48Si,1.44Mn,0.011P,0.001S,1.20Cr,0.71Mo,0.040Als)喂入0.017%RE。分析结果表明,稀土收得率95%以上,在钢中分布均匀,改变了钢中夹杂物形态,大多数夹杂呈球状,与不加RE 30CrMnMo调质钢相比,含0.017%RE30CrMnMo钢60 mm板调质后-40℃冲击功(K_(V2))由50.9~56.6 J提高至77.6~81.6 J。