钙处理低合金高强钢连铸过程中塞棒侵蚀机理及其改进  

Mechanism and improvement of erosion of stopper rod during continuous casting process of high-strength low-alloy steel after calcium treatment

作　　者：周杨鹏 杨健 鲁欣武 刘万善[2] ZHOU Yangpeng;YANG Jian;LU Xinwu;LIU Wanshan(State Key Laboratory of Advanced Special Steel,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Ningbo Iron&Steel Co.,Ltd.,Ningbo 315000,China)

机构地区：[1]上海大学材料科学与工程学院省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]宁波钢铁有限公司,浙江宁波315000

出　　处：《炼钢》2021年第3期44-50,57,共8页Steelmaking

摘　　要：针对钙处理低合金高强钢浇铸过程中塞棒的异常侵蚀问题,通过对塞棒基质层和侵蚀层进行成分分析、物相分析以及元素分布观察,并进行热力学计算分析,探究了塞棒的侵蚀机理,并提出了相应的改进措施。结果表明,钢液中过量的钙与塞棒耐火材料中的Al_(2)O_(3)、SiO_(2)在塞棒界面反应生成CaO,进而与塞棒耐火材料中的Al_(2)O_(3)、SiO_(2)反应生成低熔点的硅酸盐、钙铝酸盐等化合物是造成塞棒侵蚀的原因之一。塞棒耐火材料中的C和SiO_(2)反应生成气态的SiO、CO,然后钢液中的钙元素与SiO,CO等气体反应生成的CaO,进而生成低熔点的硅酸盐、钙铝酸盐等化合物,也可以导致塞棒的侵蚀。在侵蚀层中存在低熔点的钙黄长石和镁黄长石类化合物也会导致塞棒的侵蚀。通过规范钙处理量、选用镁碳质棒头等措施,可以明显改善塞棒的异常侵蚀问题,中间包连浇炉数由4~8炉提高至10炉以上。In view of the abnormal corrosion of stopper rod in the continuous casting process of high-strength low-alloy steel treated with calcium, the corrosion mechanism of stopper rod was clarified by thermodynamic calculation and analyzing the compositions, phases, and element distributions of base layer and erosion layer of stopper rod. The corresponding improvement measures were put forward. The results show that one of the reasons for stopper rod corrosion is that excessive calcium in molten steel reacts with Al2O3 and SiO_(2) in stopper refractory to form CaO at the erosion layer, and then react with Al_(2)O_(3) and SiO_(2) in stopper refractory to form calcium silicate, calcium aluminate and other low melting point compounds at the stopper rod interface. C and SiO_(2) in stopper rod refractories react to form gaseous SiO and CO,and then Ca in molten steel reacts with SiO,CO to produce CaO,which can also form calcium silicate, calcium aluminate and other low melting point compounds, resulting in stopper rod erosion. The existence of anorthosite and magnesia feldspar with low melting point in the erosive layer can also lead to stopper rod erosion. The abnormal erosion of stopper can be obviously improved by optimizing Si-Ca addition amount and selecting MgO-C rod head, the number of tundish continuous casting heats increase from 4-8 heats to more than 10 heats.

关 键 词：低合金高强钢 塞棒侵蚀 钙处理 侵蚀机理 

分 类 号：TF777[冶金工程—钢铁冶金]