120 t RH-LF生产低碳钢QD08的工艺实践

Process Practice of Low Carbon Steel QD08 Production by 120 t RH-LF

介绍了芜湖新兴铸管有限责任公司炼钢厂采用RH-LF精炼法生产低碳钢QD08的工艺实践。通过对转炉出站钢水初始条件,RH真空脱碳原理和过程控制,后续LF冶炼3个方面的分析研究,结果表明,初始钢水控制条件为[C] 0.04%～0.10%,[0]>300×10^(-6),转炉终点出钢温度T≥1 650℃。随真空处理时间延长,真空度降低,真空室内P_(CO)减少,碳氧浓度积呈降低的趋势,真空室内因发生碳氧反应进行脱碳,RH真空脱碳满足热力学条件;脱碳速率的变化规律为先增大后减小,脱碳速率有一定的规律;RH真空处理后的钢水需在LF完成脱硫、升温、合金化等操作,并且需保证终渣量20～23 kg/t,终渣(FeO)+(MnO)<1.2%,碱度R≥3.5等工艺条件。

This paper introduces the practice of producing low carbon steel QD08 by using RH-LF refining method at Wuhu Xinxing Pipe Co Ltd. We analyzed and studied the initial conditions of converter outbound molten steel, RH vacuum decarburization principle and process control, LF smelting from three aspects. The results show that the initial molten steel control conditions are [ C] 0. 04%~0. 010%, [0] >300 x 10-6, and the converter end temperature T≥1650 ℃. With the increase of the vacuum treatment time, the vacuum degree decreased, the PCO in the vacuum chamber decreased, the concentration of carbon and oxygen decreased, and the decarburization was carried out in the vacuum chamber. The vacuum decarburization was determined by RH vacuum decarburization. The decarburization rate changed increase first and then decrease,the decarburization rate has some regularity. After the RH vacuum treatment, the molten steel needs to be operated in the LF, such as desulfurization, heating and alloying, and the amount of slag is 20 ~ 23 kg/t, final slag( FeO) +(MnO) <1.2%, R≥3.5.