含B齿条钢电渣重熔渣系设计  

Design of ESR slag for remelting B-containing rack steel

作　　者：张永娇 孔令种 臧喜民[1] 李世森 张滨雁 王同君 ZHANG Yongjiao;KONG Lingzhong;ZANG Ximin;LI Shisen;ZHANG Binyan;WANG Tongjun(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051

出　　处：《中国冶金》2023年第8期92-103,共12页China Metallurgy

基　　金：国家自然科学基金资助项目(52174317,52274337);辽宁省重大科技专项计划资助项目(2020JH1/1010001)。

摘　　要：齿条钢作为海上钻井平台用钢,其规格与质量对海洋平台的适用范围、寿命有着重要影响。为抑制齿条钢在电渣重熔(ESR)过程钢中B元素的氧化烧损,保证重熔过程的顺行与低成本,结合齿条钢的熔点与CaF_(2)-CaO-Al_(2)O_(3)相图,设计出熔化温度符合齿条钢冶炼要求的基础渣系,利用FactSage 8.2软件和相关经验公式,研究了MgO和B_(2)O_(3)对基础渣系的熔点、黏度、电导率等物理性能的影响。基于炉渣结构的共存理论建立质量作用浓度计算模型,考察了渣系中MgO和B_(2)O_(3)的含量和渣中溶解氧与平衡B元素含量的关系,从而得到适宜重熔含B齿条钢的电渣重熔渣系,并通过高温试验对渣系的黏度进行了测定。结果表明,适宜重熔齿条钢渣系的熔点范围为1 309~1 409℃,MgO会降低熔渣的电导率、提高黏度,但MgO对渣系的氧势以及B_(2)O_(3)的活度几乎没影响;随着渣系中B_(2)O_(3)含量的增加,各渣系的转折点温度越来越低,渣系中高熔点物相的析出量减少;性能最良好的重熔含B齿条钢用渣为57.08%CaF_(2)-20.83%CaO-22.09%Al_(2)O_(3)-4%MgO-5%B_(2)O_(3)。The specification and quality of rack steel used for offshore drilling platforms have an important impact on the scope and life of offshore platforms.In order to inhibit the oxidative burn loss of B element in steel in the process of electroslag remelting(ESR),and ensure the prograde of the remelting process and low cost,the basic slag with qualified melting temperature was designed by combining the melting point of rack steel and the CaF_(2)-CaO-Al_(2)O_(3) phase diagram.The effects of MgO and B_(2)O_(3) on the melting point,viscosity,and electrical conductivity of basic slag were studied using FactSage 8.2 software and relevant empirical formulas.The relationship between the content of MgO and B_(2)O_(3) and the dissolved oxygen and the equilibrium B element content was analyzed by the mass action concentrations based on the coexistence theory of slag structure.The suitable electroslag remelting slag for remelting B-containing rack steel was obtained,and the viscosity of the slag was determined by high temperature test.The results show that the melting point range of suitable slag for remelting rack steel is 1309-1409℃,and MgO can reduce the electrical conductivity of slag and improve the viscosity,but MgO has almost no effect on the oxygen potential and activity of B_(2)O_(3).With the increase of B_(2)O_(3) content in the slag,both the turning point temperature and the precipitation amount of the high melting point phase decreases.The slag used for remelting B-containing rack steel with the best performance is 57.08%CaF_(2)-20.83%CaO-22.09%Al_(2)O_(3)-4%MgO-5%B_(2)O_(3).

关 键 词：电渣重熔 齿条钢 B_(2)O_(3) 黏度 活度 电导率 

分 类 号：TF142[冶金工程—冶金物理化学]