Fe-Cr-Ni合金连铸坯皮下裂纹研究  

Investigation on Subsurface Cracks in Continuously Cast Fe-Cr-Ni Alloy Slab

作　　者：李元[1] LI Yuan(Baosteel Special Steel Co.,Ltd.,Shanghai 200940,China)

机构地区：[1]宝钢特钢有限公司,上海200940

出　　处：《上海金属》2019年第1期94-97,共4页Shanghai Metals

摘　　要：目前,Fe-Cr-Ni耐蚀合金连铸坯往往会产生皮下裂纹。为此,采用金相试验、电子探针分析和凝固过程的原位观察等方法,研究了150 mm厚×1 150 mm长的Fe-Cr-Ni合金连铸坯产生皮下裂纹的原因。试验结果表明,皮下裂纹大多发生在Fe-Cr-Ni合金连铸坯凝固前沿的晶界,该区域发现有大量的TiO_2、Al_2O_3等氧化物,这是Fe-Cr-Ni合金中Al和Ti元素与保护渣中的SiO_2反应的产物。此外,皮下裂纹内有钠和钾等元素,结晶器内化渣困难,弯月面处的保护渣易被卷入连铸坯皮下区域。Fe-Cr-Ni合金连铸坯的皮下裂纹主要是保护渣及其反应产物造成的。At present,subsurface cracks often occur in continuously cast slab of corrosionresistant Fe-Cr-Ni alloy.For this fact,the reason why the subsurface cracks formed in a continuously cast Fe-Cr-Ni alloy slab 150mm thick by 1150mm long was investigated with the use of metallographic examination,electron probe analysis,and in situ survey during the solidifying.The results showed that the subsurface cracks occurred largely in grain boundaries of the solidified Fe-Cr-Ni alloy slab front where a large amount of oxides such as TiO 2 and Al 2O 3 which stemmed from reaction of Al and Ti present in Fe-Cr-Ni alloy with SiO2 present in protecting slag were observed.Besides,elements such as sodium and potassium were present in the subsurface crack.The slagging was difficult to perform in the mould,and protecting slag lain in meniscus was easy to be drawn into the subsurface area.The subsurface cracks was mainly attributed to protecting slag and its reaction products.

关 键 词：皮下裂纹 FE-CR-NI合金 连铸坯 

分 类 号：TG249.7[金属学及工艺—铸造]