A dephosphorization production process of h08a series steel grades

Abstract

The invention discloses an H08A-series steel dephosphorization production technology. The H08A-series steel dephosphorization production technology comprises the following steps of iron mixing and feeding, specifically, lime is added before iron mixing, oxidized scales or sintering and returning mines are added along with steel scraps for packing, and when blowing starts to be conducted after ironmixing is finished, the oxidized scales and part of auxiliary materials such as lightly-burnt dolomite are added; and slagging and dephosphorizing, specifically, lime is added in the oxygen lance blowing process, the alkalinity is controlled within the range of 1.5-1.7 in the earlier stage and controlled within the range of 2.5-2.8 in the later stage, and dephosphorizing is conducted by reasonably controlling the lance position and combining with double-slag operation. According to the technical scheme, the super-low phosphorus standard can be achieved, the lime consumption is within the controllable range in the smelting process, and the H08A-series steel dephosphorization production technology has the good effects that the blowing loss is reduced, the steel consumption is reduced, the first-hit yield of the end point of a converter is increased, and the life of a converter lining can be prolonged.

Description

technical field [0001] The invention relates to the technical field of iron and steel smelting, in particular to a dephosphorization production process for H08A series steel grades. Background technique [0002] Phosphorus is a harmful element that needs to be removed when refining most steel types. Generally, the phosphorus content is required to be less than 0.03%. When the phosphorus content is high, the plasticity and impact toughness of the steel will be reduced. At low temperatures, "cold and brittle" will appear Therefore, dephosphorization is one of the main tasks of converter steelmaking. In the prior art, the dephosphorization method of oxygen top-blown converter is generally used, and the single slag method or double slag method is used for slagging operation, and the dephosphorization efficiency can reach the efficiency 85% to 95%, due to the high basicity, high slag temperature and high FeO content of the final slag, it is helpful for the early lime melting to s...

AI Technical Summary

Problems solved by technology

[0002] Phosphorus is a harmful element that needs to be removed when refining most steel types. Generally, the phosphorus content is required to be less than 0.03%. When the phosphorus content is high, the plasticity and impact toughness of the steel will be reduced. At low temperatures, "cold and brittle" will appear Therefore, dephosphorization is one of the main tasks of converter steelmaking. In the prior art, the dephosphorization method of oxygen top-blown converter is generally used, and the single slag method or double slag method is used for slagging operation, and the dephosphorization efficiency can reach the efficiency 85% to 95%, due to the high basicity, high slag temperature and high FeO content of the final slag, it is helpful for the early lime melting to slag and dephosphorization. It has outstanding advantages and can meet the composition requirements of most steel types, but for Some steel grades with special composition requirements, especially low-carbon steel grades with a phosphorus and sulfur content below 0.005%, are difficult to complete with traditional operating techniques. Severe splashing, rise of the bottom of the furnace, etc., so an effective and feasible process is needed to replace the original process