钛微合金化抗低温冲击H型钢Q345E的开发

山钢股份莱芜分公司炼钢厂原采用铌镍硼微合金化生产抗低温冲击H型钢Q345E,但产品冲击性能波动大、合格率低、效益差。为此,对原生产工艺进行优化调整,采用低碳钛微合金化,使用钝化镁粒脱硫,铝锰铁、铝粒脱氧,连铸保护浇注,调整轧钢工艺并加强各工序控制,开发的产品-20℃冲击功120~160 J/cm2,-45℃冲击功70~100 J/cm2,产品成材合格率85%以上,吨钢降低成本300元以上。

Development of Low-temperature Shock Resisting H-beam Q345E Steel Microalloying by Tianium

The Steelmaking Plant of Laiwu Branch Company of Shandong Iron and Steel Co., Ltd. formerly adopted Nb, Ni and B microalloying to produce low-temperature shock resisting H-beam Q345E steel, but the impact property of the products had large fluctuation, low percent of pass and poor benefits. Therefore, producers optimized and adjusted the production processes, adopted low-carbon and Ti microalloying, used passivated magnesium particles desulfurization, used aluminum ferromanganese and aluminum particles deoxidation and protective casting, adjusted rolling process and strengthened the control for each procedure. The absorbed-in fracture energy of developed product at-20℃is between 120 and 160 J/cm2 and at-45℃is between 70 and 100 J/cm2. The qualified rate of finished products is 85%above. The cost reduced by 300 Yuan RMB per ton.