摘要
为研究预应力高强钢PSB930铸坯出现的表面凹陷、裂纹等缺陷的形成原因。通过铸坯酸洗、化学成分、扫描电镜及能谱分析等方法,确认了PSB930铸坯的凹陷缺陷主要是结晶器内冷却不当形成的应力集中所致,表面裂纹缺陷主要是硫含量高形成的硫化物夹杂引起,并在冷却过程中受热应力和硫化物夹杂共同作用产生沿晶裂纹。通过优化精炼脱氧脱硫制度,调整连铸结晶器水量为115~120 m^(3)/h,二冷比水量为0.5 L/kg的配水比为31∶26∶20∶13∶10,控制中间包过热度在20~30℃、优化保护渣碱度至0.95、黏度至2.5 Pa·s等措施,铸坯表面凹陷及裂纹缺陷基本消除,保证了轧材的产品质量。
In order to study the cause of surface depression,crack and other defects of PSB930 billet.By means of pickling,chemical composition,scanning electron microscope and energy spectrum analysis,it is confirmed that the concave defects of PSB930 billet are mainly caused by the stress concentration formed by improper cooling in the mold,and the surface crack defects are mainly caused by sulfide inclusions formed by high S content,and the intergranular cracks produced by the combined action of thermal stress and sulfide inclusions during cooling.By optimizing the refining deoxidation and desulfurization system,adjusting the water volume of the continuous casting mold to 115-120 m^(3)/h,the specific water volume of the secondary cooling to 0.5 L/kg,the water distribution ratio to 31∶26∶20∶13∶10,controlling the superheat of the tundish to 20-30℃,optimizing the basicity of the mold powder to 0.95,and the viscosity to 2.5 Pa·s,the concavity and crack defects on the surface of the slab were basically eliminated,and the product quality of the rolled material was guaranteed.
作者
宋红伟
王东兴
任毅
王吾磊
杨伟勇
汪春梅
SONG Hong-wei;WANG Dong-xing;REN Yi;WANG Wu-lei;YANG Wei-yong;WANG Chun-mei(Institute of Research of Iron and Steel,Wuhu Xinxing Casting Pipe Co.,Ltd.,Wuhu 241002,Anhui,China)
出处
《连铸》
2023年第2期63-69,共7页
Continuous Casting
关键词
铸坯凹陷
脱氧
过热度
保护渣
分配比
billet depression
deoxidation
excessive heat
protecting slag
distribution ratio
