氧气瓶钢冶炼过程氮含量控制

针对气瓶钢氮含量偏高,波动大,控制困难的问题,对炼钢工序全流程钢水中氮含量展开了调查.调查结果表明,转炉终点钢液氮含量偏高,增氮主要环节为转炉出钢过程和RH精炼结束到中包开浇.针对调查结果,提出了转炉低氮钢冶炼技术、出钢过程脱氧工艺优化及连铸保护浇注等技术措施,有效的降低了转炉终点氮含量,出钢增氮和浇注过程增氮也得到了有效的控制,使成品钢水中氮含量稳定控制在50×10-6以内,减小了氮对成品钢材性能的影响.

NITROGEN CONTROL OF THE SMELTING PROCESS FOR HIGH-PRESSURE GAS BOTTLE STEEL

Aiming at the problems of high nitrogen content of the high - pressure bottle steel with big fluctuation and hard to control, the investigation on nitrogen content of the whole steelmaking process was carried out. Results indicated that the nitrogen content of steel on convert end - point was higher and the nitrogen absorption was mainly happened during tapping and the procedure from refining finished to casting beginning. Then the measures of nitrogen control such as smelting technology for low - nitrogen steel, optimization of deoxidization during tapping, protective casting technology and so on were raised. After that the nitrogen content of steel on convert end - point was reduced effectively and the nitrogen absorption during tapping and continuous casting was effectively controlled, too. The nitrogen content of the finished steel was stably controlled in 50 × 10 ^-6 and the effect of nitrogen on steel properties could be reduced.