关键词: 转炉炼钢, 少渣冶炼, 脱磷, Q355钢

Abstract: The slag-making material addition system of Q355 steel was optimized， from the traditional "three-batch feeding" mode to the "eight-batch feeding" mode， and 100 kg steel slag modifier was added in the first and third batches respectively. At the same time， the oxygen blowing system of Q355 was changed from the traditional "constant flow， high-low-low lance position" control to "variable pressure， high-low-high-low lance position" control. Base above， a converter economical smelting process suitable for the actual production of Q355 steel was developed. The practice results show that compared with the original smelting process， the total oxygen supply time of the improved process is shortened by 1 min， the hit rate of phosphorus at the end point of smelting is 100%， the average value of phosphorus removal rate at the end point is increased by 4.24%， and the average value of lgL_p is increased by 0.35. Compared with the consumption of slagging materials in the original process， the average consumption of steel lime per ton in the improved process is 34.01 kg， a decrease of 8.73 kg， and the average consumption of total slag material per ton of steel is 43.95 kg， a decrease of 9.13 kg. In addition， the average iron and steel material consumption of the improved process is 1078.02 kg/ton steel， which is 0.60 kg/ton steel less than that of the original process. The economic smelting of Q355 steel converter is realized， the consumption of slagging material and steel material is reduced， and the production cost of Q355 steel smelting is effectively reduced.

Key words: Converter Steelmaking, Economic Smelting, Dephosphorization, Q355 Steel