连铸结晶器表面防护涂层失效行为的研究进展

Research progress in failure behavior of protective coatings on surface of continuous casting mould

连铸结晶器承担着高温钢液高速振动拉坯过程中的冷却、导热、抗磨损、铸坯表面高精度成型等重要任务,是连铸生产线最关键的核心器件。本文结合结晶器表面防护涂层在国内钢厂的工程应用实践,综述了结晶器铜板表面电镀合金层和热喷涂涂层的优缺点、发展趋势以及实际工况服役后结晶器表面不同部位的主要失效形式和形成机制,为优化设计不同区域涂层成分与相应性能提供依据。同时详细介绍了项目组开展的热喷涂/真空扩散复合技术在国内主要钢厂的服役效果和应用优势。最后指出热喷涂技术将逐步取代电镀技术,成为结晶器表面防护的核心技术,并且高熵及中熵合金涂层具有巨大的应用潜力。

The continuous casting mould is the most crucial core component of the continuous casting production line,which undertakes the important tasks of cooling,heat conduction,abrasion resistance and high-precision forming of the billet surface during the high-speed vibration drawing process of the molten steel.Based on the engineering application practice of mould surface protective coatings in domestic steel plants,the advantages,disadvantages and developing trends of electroplated alloy coatings and thermal spray coatings on the surface of mould copper plate were summarized,as well as the main failure forms and formation mechanisms at different locations of mould surface after service under actual working conditions,providing the basis for optimizing the design of coating compositions and corresponding performance in different areas.Moreover,the service results and application advantages of the thermal spraying/vacuum diffusion composite technology developed by the project team in major domestic steel plants were introduced in detail.Finally,it was pointed out that thermal spraying technology will gradually replace electroplating technology and become the core technology of mold surface protection,and high entropy and medium entropy alloy coating has great application potential.