A kind of production method of low phosphorus steel

A production method and technology for low-phosphorus steel, applied in the field of iron and steel smelting, can solve the problems of large furnace lining erosion, insignificant dephosphorization effect, affecting the life of the converter, etc. Effect of TFe Content

Active Publication Date: 2018-05-25
PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

As can be seen from the above-mentioned patents, both methods use sodium compounds as dephosphorization agents. Although this can achieve a certain dephosphorization effect, the dephosphorization effect is not obvious, and the addition of sodium compounds to the converter is less erosive to the furnace lining. Large, affecting the life of the converter

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] After the 200t vanadium extracting converter has mixed iron, the temperature of the molten iron is measured at 1305°C. After the temperature measurement is completed, the oxygen-reducing lance is used for blowing, and the oxygen flow rate is controlled at 1.5Nm throughout the process. 3 / t.min, the intensity of bottom blowing nitrogen is 0.3Nm 3 / t.min control; add steelmaking converter final slag 10kg / tFe at the beginning of blowing, and control the gun position at 30mm above the reference gun position 2 minutes before blowing; add oxide scale after blowing 1min, and the amount of oxide scale is 25kg / tFe Carry out control; after 2 minutes of blowing, the lance position is controlled according to the reference lance position; 2 minutes before the end of blowing, the oxygen lance position is controlled to be 30mm above the reference lance position; semi-steel and vanadium slag are produced after blowing.

[0025] The vanadium content in molten iron is 0.330%, and the pho...

Embodiment 2

[0029] After the 120t vanadium extracting converter has mixed iron, the temperature of the molten iron is measured at 1280°C. After the temperature measurement is completed, the oxygen-reducing lance is used for blowing, and the oxygen flow rate is controlled at 3.0Nm throughout the process. 3 / t.min, the intensity of bottom blowing nitrogen is 0.2Nm 3 / t.min control; add steelmaking converter final slag 7kg / tFe at the beginning of blowing, and control the gun position 20mm above the reference gun position 2 minutes before blowing; add oxide scale after blowing 2min, and the amount of oxide scale is 20kg / tFe Control, and at the same time the gun position is controlled according to the reference gun position; the oxygen lance gun position is controlled to 40mm above the reference gun position 2 minutes before the end of the blowing; semi-steel and vanadium slag are produced after the blowing is completed.

[0030] The vanadium content in molten iron is 0.302%, and the phosphoru...

Embodiment 3

[0034] After the 200t vanadium extracting converter has mixed iron, the temperature of the molten iron is measured at 1250°C. After the temperature measurement is completed, the oxygen-reducing lance is used for blowing, and the oxygen flow rate is controlled at 2Nm throughout the process.3 / t.min, the intensity of bottom blowing nitrogen is 0.4Nm 3 / t.min control; add steelmaking converter final slag 5kg / tFe at the beginning of blowing, blowing 1.5min gun position is controlled by 10mm above the reference gun position; blowing 1.5min after adding iron oxide scale, the amount of oxide scale is 15kg / t. tFe is used for control; after 2 minutes of blowing, the gun position is controlled according to the reference gun position; 2 minutes before the end of blowing, the position of the oxygen lance is controlled to be 50 mm above the reference gun position; after blowing, semi-steel and vanadium slag are produced.

[0035] The vanadium content in molten iron is 0.386%, and the phosph...

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PUM

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Abstract

The invention belongs to the field of steel smelting, and particularly relates to a production method of low-phosphorous steel in order to solve the problem that the efficiency of vanadium extraction and dephosphorization from molten iron is low by using the conventional method and to reduce the content of TFe in vanadium slag. The production method of the low-phosphorous steel comprises the following steps: A, after iron is added to a vanadium extraction converter, an oxygen reducing lance carries out converting, the flow of oxygen is controlled at 1.5-3.0Nm<3> / t.min throughout, and the strength of bottom blowing nitrogen is 0.2-0.4N<3> / t.min; B, the converting begins, final slag of a steel-making converter is added, 2min before the converting, a lance position is controlled at 10-30mm above a reference lance position, 1-2min after the converting, scale or other high-iron oxides are added, 2min after the converting, the lance position is controlled according to the reference lance position, and 2min before the converting is finished, the lance position is controlled at 30-50mm above the reference lance position; C, after the converting is finished, semisteel and vanadium slag are discharged; and D, the semisteel is added to a steelmaking furnace, the alkalinity of pre-slag is controlled at 2.0-3.0, the alkalinity of secondary slag is controlled at 3.0-4.5, and the tapping temperature is controlled according to the requirement of the steel type.

Description

technical field [0001] The invention belongs to the field of iron and steel smelting, and in particular relates to a production method of low-phosphorus steel. Background technique [0002] Phosphorus is a harmful element in most steel grades. In recent years, with the rapid development of science and technology, low-temperature steel, marine steel, hydrogen-induced cracking-resistant steel and steel for some thick plates must not only have extremely low sulfur content, but also require the phosphorus content in steel to be less than 0.01% or 0.005%. Since the 1980s, various treatment methods have been developed for the pre-dephosphorization of molten iron. The dephosphorization pretreatment of molten iron is carried out in the converter, and both methods have been applied in industry. Dephosphorization of ladles or torpedo tanks mainly has problems such as large temperature drop, severe splashing during oxygen blowing to compensate for temperature drop, and long processi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C33/04C21C7/072
CPCC21C7/072C22C33/04Y02P10/20
Inventor 陈炼谢兵戈文荪曾建华王建卓钧王二军付新瑞黄正华黄东平
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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