Smelting process for producing ultra-low phosphorous steel by converter

Abstract

The invention discloses a smelting process for producing ultra-low phosphorous steel by a converter. In the process, molten iron subjected to primary desulfurization is subjected to a multiple slagging smelting process through the converter to produce the ultra-low phosphorous steel. The process comprises the following steps of: removing phosphorus from the molten iron subjected to primary desulfurization by adopting a deslagging and blowing method at the early stage and the later stage twice, adjusting slag by using silicon iron, pouring into a slag pot to make the slat pot full each time, and well controlling the process temperature: the target temperature at the early stage is between 1,350 and 1,400 DEG C, the highest temperature is less than or equal to 1,450 DEG C, the temperature measured when a sublance blows 80 percent of the steel is between 1,530 and 1,550 DEG C and the target terminal temperature is between 1,610 and 1,630 DEG C to obtain the ultra-low phosphorous steel with less than or equal to 0.005 mass percent of phosphorous. The molten iron subjected to primary desulfurization is subjected to multiple deslagging through the converter to produce the ultra-low phosphorous steel, and the process has the advantages of small physical heat loss of the molten iron, high yield, high efficiency, low alloy consumption, low cost and energy conservation.

Description

technical field [0001] The invention relates to a smelting process for ultra-low phosphorus steel, in particular to a smelting process for producing ultra-low phosphorus steel by a double-slag or multi-slag method in a converter. Background technique [0002] At present, relevant manufacturers at home and abroad are using three desiliconization (desiliconization, descaling, desulphurization) of molten iron + double converter (one converter dephosphorization, another converter decarburization) to produce ultra-low phosphorus steel. The disadvantage of this production process is: molten iron Low temperature, large physical heat loss of molten iron, high alloy consumption, long smelting cycle, large energy waste, low output and high production cost. Contents of the invention [0003] In order to overcome the problems existing in the prior art, the object of the present invention is to provide a smelting process for ultra-low phosphorus steel produced by a converter. The heat...

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Problems solved by technology

[0002] At present, relevant manufacturers at home and abroad are using three desiliconization (desiliconization, descaling, desulfurization) of molten iron + double converter (one converter dephosphorization, another converter decarburization) to produce ultra-low phosphorus steel. The disadvantage of this production process is: molten iron Low temperature, large physical heat loss of molten iron, high alloy consumption, long smelting cycle, large energy waste, low output, high production cost