Abstract

The technology of melting and ladle treatment of pipe steels K56, 09G2S, and KEI55 is analyzed to determine the factors affecting the metal quality and the formation and removal of oxide nonmetallic inclusions (NIs). To determine the causes of increasing the phosphorus content in the metal in an ladle–furnace unit (LFU), we develop a mathematical model to calculate the slag mass entering the metal on tapping from an electric arc furnace (EAF) and remaining on the steel ladle walls from the previous heat. This model is based on a system of material balance equations. Fractional gas analysis and scanning electron microscopy with electron-probe microanalysis are used to study the metal samples taken along the entire technological scheme of melting and ladle treatment of K56, 09G2S, and KEI55 pipe steels. The total content of oxygen and nitrogen in the selected metal samples, the characteristic types of oxide NIs, and their number are determined at each stage of ladle treatment and casting. The steel samples are shown to contain the most unfavorable for pipe steels undeformable NIs, namely, aluminates, aluminosilicates, and calcium aluminosilicates. The increase in the aluminum–magnesium spinel NI content in the metal samples is assumed to be due to the influence of deoxidizers and the inert gas flow rate on the destruction of the lining. The introduction of ferroniobium with an increase in the argon blowing intensity is found to decrease the nitrogen content in the metal due to the removal of formed titanium nitrides into a slag. The increase in the oxygen and nitrogen content in the samples taken from a continuous casting machine for the heats of 09G2S and KEI55 steels is assumed to indicate secondary oxidation of the metal on casting. A software package is developed using the C++ programming language and the Visual Studio environment in order to predict the number of various types of NIs having formed during ladle treatment depending on its conditions. The convergence of the calculated and experimental values is shown to be satisfactory.

中文翻译：

---

钢管钢包处理过程中非金属夹杂物的形成

摘要

分析了管钢K56、09G2S、KEI55的熔炼和钢包处理工艺，确定了影响金属质量和氧化物非金属夹杂物（NIs）形成和去除的因素。为了确定钢包 - 熔炉装置 (LFU) 中金属中磷含量增加的原因，我们开发了一个数学模型来计算从电弧炉 (EAF) 出钢时进入金属并留在钢上的渣质量钢包壁从以前的热量。该模型基于物料平衡方程系统。气体分馏分析和带电子探针微量分析的扫描电子显微镜被用来研究沿 K56、09G2S 和 KEI55 管钢熔炼和钢包处理的整个工艺方案采集的金属样品。在钢包处理和铸造的每个阶段确定所选金属样品中氧和氮的总含量、氧化物 NI 的特征类型及其数量。钢样品显示含有最不利于管钢不可变形的 NI，即铝酸盐、铝硅酸盐和铝硅酸钙。金属样品中铝镁尖晶石 NI 含量的增加被认为是由于脱氧剂和惰性气体流速对衬里破坏的影响。发现随着吹氩强度的增加，引入铌铁会降低金属中的氮含量，因为形成的氮化钛被去除到炉渣中。假设从连铸机中取出的样品中氧和氮含量的增加用于 09G2S 和 KEI55 钢的炉次，表明金属在铸造时发生了二次氧化。使用 C++ 编程语言和 Visual Studio 环境开发了一个软件包，以预测在钢包处理期间根据其条件形成的各种类型的 NI 的数量。计算值和实验值的收敛性令人满意。