低碳原辅料对钢水增碳影响规律研究及其应用-钢铁冶金专业论文.docxVIP

万方数据 万方数据 摘 要 近来超低碳钢（含 C50ppm）取得了疾速发展，其成分特点是：超低碳含量、 微合金化、钢质纯净 。在冶炼和铸造工艺条件限制下，生产的超低碳钢诸多方面面 临严峻挑战。超低碳钢冶炼从 RH 精炼结束后到铸坯过程中所使用的一些含碳的原 辅料会向钢液中增碳对钢液碳含量造成一定的影响。超低碳钢的增碳问题是国内外 冶金工业亟待解决的问题。 本文通过某钢厂的 MA 系列汽车板的生产实践研究，分析从 RH 精炼结束至铸 坯的各种含碳原辅料对钢液增碳机理及影响规律，得出如下结论： （1）含碳钢包砖衬、中包涂料、中包覆盖剂、浸入式水口中的游离碳含量对钢 液增碳是有一定影响的。在不影响其他性能情况下，减少这些原辅料中的游离碳配 比，可以减少钢水增碳。 （2）每浇次的第一炉增碳最严重，这与首炉钢覆盖剂的大量消耗有关。 （3）换包开浇时即每炉钢的浇铸初期，中包液面波动和温度的波动导致覆盖剂 大量卷入引起中包钢水增碳。 （4）结晶器增碳的主要原因是保护渣富碳层。非稳态操作条件下，保护渣富碳 层卷入钢液中的弯月面处，导致铸坯表面增碳严重。 关键词：超低碳钢；增碳；覆盖剂；保护渣；富碳层 I Abstract Recently, ultra-low carbon steel (C50ppm) has achieved rapid development, its composition features are: low carbon content, microalloyed, purity. Its production process is complex and strict manufacturing technology. Due to the smelting and casting technology conditions, the production of ultra-low carbon steel faced severe challenges in many aspects. Some raw materials containing carbon are used from the end of RH to casting slab what may impact the carbon content of liquid steel. The carbonization of ultra- low carbon steel is one of the problem to be solved in metallurgical industry. In this paper, the carbonization of ultra-low carbon steel from the end of RH to casting slab by some low carbon raw materials was study through the production of MA series automobile plate in a steel mill. The following conclusions can be obtained： Free carbon in carbon-containing ladle brick, tundish coatings, tundish covering flux and submerged nozzle may cause liquid steel carbureting. In order to reduce the increase of carbon in liquid steel, free carbon in this raw materials should be cut down. The carbonization of the fist ladle in every cast is serious, because tundish covering is used too much for the fist ladle. Tundish covering is drawn into liquid by the liquid level fluctuation and temperature fluctuations at the beginning of each ladle. Rich carbon layer of mold powder is the main cause of carbonization in mold. Rich carbon layer may be drawn into meniscus of liquid st