A kind of argon blowing refining method for producing SPHC steel

Abstract

The invention provides a liquid steel purification method for steel plate heat commercial (SPHC) steel. A continuous casting tundish argon blowing upper nozzle pocket block is adopted, argon is blown in, liquid about to enter an upper nozzle is subjected to gas washing, upward floating and removing of inclusions are facilitated, a certain number of argon bubbles enter a submersed nozzle along the inner wall of the upper nozzle along with steel flow, stable and continuous annular gas flow is formed, and the problem of nodulation of the tundish nozzles is restrained. Meanwhile, an appropriate number of high-alkalinity tundish covering agents are added onto the tundish liquid face in the area over the argon blowing upper nozzle pocket block in each furnace, thus the inclusions are driven by the argon bubbles to float upward to the tundish liquid face to be absorbed in time and removed effectively by the high-alkalinity tundish covering agents, and the inclusion removing rate is increased. By applying the argon blowing refining method, the problem of eye sleeving of the continuous casting tundish nozzles is solved, the number of continuous furnace casting reaches 30 furnaces or above, thus the quantity of the metallographical inclusions in a rolled material is reduced by 40% or above on the year-on-year basis, and the quality defect caused by the inclusions in the steel is overcome.

Description

technical field [0001] The invention relates to an argon blowing refining method for producing SPHC steel grades, and belongs to the technical field of iron and steel metallurgy continuous casting tundish metallurgical technology. Background technique [0002] In order to reduce the production cost of SPHC, the existing technology adopts the slag washing material added with the steel flow during the tapping process of the converter, that is, the slag washing technology, and the LF refining furnace adopts the argon blowing straight up process, but the following problems exist in actual production: (1 ) The tapping temperature of the converter is required to be 1680-1700°C, and the lining of the converter is severely eroded, which cannot withstand continuous and mass production; The cost of continuous casting refractory materials is high; (3) The inclusions in molten steel are high, resulting in quality defects such as peeling of rolled products, and the quality of rolled prod...

AI Technical Summary

Problems solved by technology

[0002] In order to reduce the production cost of SPHC, the existing technology adopts the slag washing material added with the steel flow during the tapping process of the converter, that is, the slag washing technology, and the LF refining furnace adopts the argon blowing straight up process, but the following problems exist in actual production: (1 ) The tapping temperature of the converter is required to be 1680-1700°C, and the lining of the converter is severely eroded, which cannot withstand continuous and mass production; The cost of continuous casting refractory materials is high; (3) The inclusions in molten steel are high, resulting in quality defects such as peeling of rolled products, and the quality of rolled products is difficult to guarantee

The disadvantages of this patented technology: poor castability of molten steel, easy occurrence of over-holes in the nozzle of the continuous casting tundish, low number of continuous casting furnaces, and mass production cannot be carried out

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