为调控钢中硫化物的夹杂形态和分布, 提升产品品质, 以碲处理工艺代替钙处理工艺开发了高品质含碲非调质钢 38MnVS6, 但在生产过程中会产生水口结瘤现象. 为分析水口结瘤的形成原因, 采用 X 射线衍射分析(X-ray diffraction, XRD)、扫描电镜分析及热力学计算等, 解析了水口结瘤物的主要物相及与钢中夹杂物的关系, 探究了其与碲处理工艺的关联性. 研究结果表明, 水口结瘤物主要由 CaO$\cdot $2Al$_{2}$O$_{3}$ 和 MgO$\cdot $Al$_{2}$O$_{3}$ 组成, 不含碲相关的物相, 其与钢中的氧化物夹杂成分相近, 因此水口结瘤并不是由碲直接造成的. 在碲处理工艺替换钙处理工艺后, 钢中钙质量百分比浓度不足以将 Al$_{2}$O$_{3}$ 改质为低熔点 12CaO$\cdot $7Al$_{2}$O$_{3}$, 当前钢中 Al 和 Ca 主要生成的钙铝酸盐夹杂为 CaO$\cdot $2Al$_{2}$O$_{3}$. 此外, 钢中残余的少量 Mg 使 Al$_{2}$O$_{3}$ 转变为 MgO$\cdot $Al$_{2}$O$_{3}$, 对应的 Mg 质量百分比浓度为 0.25$\times $10$^{-6}\sim $1.46$\times $10$^{-6}$. 当钢液流经水口时, CaO$\cdot $2Al$_{2}$O$_{3}$ 与 MgO$\cdot $Al$_{2}$O$_{3}$ 在水口内壁相互烧结黏附, 不断聚集增厚, 最终形成水口结瘤.

To control the morphology and distribution of sulfide inclusions in steel and to improve the product quality, calcium treatment was replaced by tellurium treatment, yielding high-quality, non-quenched, and tempered tellurium-containing 38MnVS6 steel. However, the production process was hampered by nozzle clogging. In order to determine its cause, X-ray diffraction (XRD) analysis, scanning electron microscopy analysis, and thermodynamic calculations were carried out. The relationship between the main phases of the clogs and the inclusions in the steel was constructed, and the effect of tellurium treatment on nozzle clogging was explored. The results show that the clogs are mainly composed of CaO$\cdot $2Al$_{2}$O$_{3}$ and MgO$\cdot $Al$_{2}$O$_{3}$ and do not contain any tellurium phases, which have a similar composition to oxide inclusions. Therefore, nozzle clogging is not directly caused by tellurium. By treating the steel with tellurium instead of calcium, the calcium content in the steel is insufficiently high for transforming Al$_{2}$O$_{3}$ to low-melting-point 12CaO$\cdot $7Al$_{2}$O$_{3}$. The main calcium aluminate inclusion produced using the specified Al and Ca contents is CaO$\cdot $2Al$_{2}$O$_{3}$. In addition, owing to the small amount of residual Mg ($0.25\times10^{-6}\sim 1.46\times10^{-6}$) in the steel, Al$_{2}$O$_{3}$ is converted into MgO$\cdot $Al$_{2}$O$_{3}$. When the molten steel flows through the nozzle, CaO$\cdot $2Al$_{2}$O$_{3}$ and MgO$\cdot $Al$_{2}$O$_{3}$ sinter and adhere to each other on the inner wall of the nozzle. The inclusions continuously accumulate and gradually thicken, finally resulting in nozzle clogging.