高碳钢小方坯粘结漏钢形成原因分析与控制

Analysis and prevention of sticker breakout for high carbon steel billets

针对某厂高碳钢小方坯粘接漏钢发生率高的问题,通过观察高碳钢漏钢坯壳组织形貌,分析其在结晶器中运动规律,研究了粘结漏钢的形成机理。结合现场连铸生产过程参数和保护渣使用情况的调查,弄清了造成该钢种粘结漏钢的主要原因。凝固坯壳在二次弯月面附近发生粘结,在结晶器上下振动过程中粘结处坯壳发生拉断、重接和再拉断,漏钢破裂处随之逐渐下行,直至结晶器出口处发生漏钢。调查分析发现,保护渣润滑性能不良、结晶器液面波动大、过热度和拉速不合适是该钢厂高碳钢小方坯粘结漏钢的形成原因。采用可行的控制措施后,高碳钢小方坯粘结漏钢发生率从8.4%降低到1.5%。

In order to solve the problem that sticker breakout ratio of high carbon steel billets were high in certain plant, sticker breakout mechanism was studied by analyzing the microstructure evolution and the movement law of the shell in the mold. The main reason of sticker breakout was found out by investigating the continuous casting production parameters and the mould powder characteristics. The results showed that sticking originated at the secondary meniscus and then the sticking shell was torn, after that, with several re-solidification and tear with the mold＇s oscillating up and down, the breakout happened till the sticker shell came out of the mold. The causes to sticker breakout of high carbon steel billets had been analyzed, including mold powder, mold level fluctuation, superheat and casting speed. After adopting feasible control measures, the sticker breakout ratio of the high carbon billet decreased from 8.4 % to 1.5%.