Method for smelting and returning high-silicon molten steel by converter
阅读说明：本技术 一种转炉冶炼回炉高硅钢水的方法 (Method for smelting and returning high-silicon molten steel by converter ) 是由 尚德义 陈晨 王富亮 马宁 赵自鑫 于 2021-09-14 设计创作，主要内容包括：本发明涉及一种转炉冶炼回炉高硅钢水的方法,转炉中兑入回炉高硅钢水,再兑入铁水至预定装入量,使转炉中的钢水硅含量≤1.0％；转炉采用双渣冶炼的方法,加入的造渣料包括活性石灰、白云石、轻烧白云石、烧结矿；吹炼时氧累达到83％-85％时使用副枪测量TSC,按TSC测量数据吹炼至钢水目标成分和目标温度后提枪,出钢。本发明实现转炉冶炼回炉高硅钢水的稳定控制。降低钢厂经济损失,减少炼钢生产事故率。提高了炼钢生产作业率。(The invention relates to a method for smelting recycled high-silicon molten steel in a converter, which comprises the steps of adding recycled high-silicon molten steel into the converter, and adding the molten steel to a preset loading amount to ensure that the silicon content of the molten steel in the converter is less than or equal to 1.0 percent; the converter adopts a double-slag smelting method, and the added slagging material comprises active lime, dolomite, light-burned dolomite and sinter; and (3) measuring TSC by using a sublance when oxygen accumulation reaches 83-85% during blowing, carrying out blowing according to TSC measurement data until the target components and the target temperature of molten steel are reached, and then carrying out gun lifting and tapping. The invention realizes the stable control of the converter smelting returning high-silicon steel water. The economic loss of a steel mill is reduced, and the accident rate of steel-making production is reduced. The operation rate of steel-making production is improved.)
1. A method for smelting and returning high-silicon molten steel by a converter comprises the following process routes: the method comprises the following steps of (1) remelting high-silicon steel water → a converter → an argon station → refining → a casting machine, and is characterized by comprising the following specific steps:
1) loading control
Adding the returning high-silicon molten steel into the converter, and then adding the molten steel to a preset loading amount to ensure that the silicon content of the molten steel in the converter is less than or equal to 1.0 percent;
2) slagging control
The converter adopts a double-slag smelting method, and the added slagging material comprises active lime, dolomite, light-burned dolomite and sinter; the total amount of the added sinter is [ (molten iron temperature-1300) + (molten steel silicon content/n-0.3) × 200+180 ]/20; unit: t; n is the molten steel adding frequency;
a. controlling slag charge before slag discharge: adding amount of active lime: 15 plus or minus 0.5 kg/t; the addition amount of dolomite and light-burned dolomite: 15 plus or minus 0.5 kg/t; the total amount of the added sinter is 1 plus or minus 0.5 t;
b. controlling slag charge after slag discharge: adding amount of active lime: 25 plus or minus 0.5 kg/t; the addition amount of dolomite and light-burned dolomite: 5 plus or minus 0.5 kg/t; the addition amount of the sintering ore is the total addition amount of the sintering ore, namely the amount of the sintering ore added before slag discharge;
3) gun position control
a. Opening a blowing gun: 2600mm-2700mm, open oxygen blast pressure: 0.9MPa to 1.05MPa, and the oxygen blowing flow rate is 53700 +/-50 Nm3H; blowing for 1min +/-30 s until the position of the gun is lowered to 2400 +/-10 mm, blowing for 2min +/-30 s until the position of the gun is lowered to 2200 +/-10 mm, blowing for 3min +/-30 s, lifting the position of the gun to 2600 +/-10 mm, blowing for 4min +/-30 s until the position of the gun is raised to 3000 +/-10 mm, and then waiting for 5min +/-30 s to lift the gun and discharge slag;
b. blowing again after slag discharging, and opening a blowing gun position: 2600 + -10 mm, oxygen flow 48000 + -50 Nm3H, after the fire is successfully struck, the position of the gun is lifted to 2800 +/-10 mm, and the oxygen blowing flow is adjusted to 53700 +/-50 Nm3/h；
4) Endpoint control
And measuring TSC by using a sublance when the oxygen is accumulated to 83-85%, blowing to a molten steel target component and a target temperature according to TSC measurement data, then lifting the sublance, and tapping.
2. The method for smelting the recycled high-silicon steel water in the converter according to claim 1, wherein in the step 1), according to the silicon content of the recycled high-silicon steel water, the amount of the recycled high-silicon steel molten steel added into the converter is as follows:
the silicon content of the returned high-silicon steel water is less than or equal to 2 percent, and 1/2 furnace-returned high-silicon steel water is added into the converter;
the silicon content of the recycled high-silicon steel water is less than 3 percent and more than 2 percent, and the recycled high-silicon steel water of which the ratio is less than or equal to 1/3 is added into the converter;
the silicon content of the returned high-silicon steel water is more than or equal to 3 percent, and the returned high-silicon steel water which is less than or equal to 1/4 percent is added into the converter.
3. The method for smelting and returning the high silicon steel water to the converter according to claim 1, wherein in the step 2) a, the slag is added in two batches after being blown for 30 s.
Technical Field
The invention relates to the technical field of ferrous metallurgy, in particular to a method for smelting and returning high-silicon molten steel by a converter.
Background
When the high-silicon steel water is produced, a continuous casting machine is in failure, the high-silicon steel water has an accident of no castability caused by the fact that the components are not equal before casting, in order to avoid larger economic loss, the high-silicon steel water needs to be returned to a furnace and added into the converter again, the conventional raw materials for smelting the converter are molten iron and waste steel, and the content of silicon in the molten iron is generally about 0.3-0.6%. The silicon content of the common remelting molten steel is about 0.02 to 0.5 percent. However, the high silicon steel has high silicon content, which can generally reach 1.5-3.5%, so it is extremely difficult to smelt in a converter.
The high-silicon steel water with ultra-high silicon content can obviously increase the consumption of slag materials, easily cause splashing, have extremely low metal yield, and simultaneously, the excessive SiO2 in the slag can also aggravate the erosion to a furnace lining, influence the melting speed of active lime and obviously prolong the converting time.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for smelting and returning high-silicon steel water by a converter, and the aims of normal smelting of the converter, no splashing, qualified temperature and qualified components are achieved.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for smelting and returning high-silicon molten steel by a converter comprises the following process routes: the method comprises the following steps of (1) remelting high-silicon steel water → a converter → an argon station → refining → a casting machine, and specifically comprises the following steps:
1) loading control
Adding the returned high-silicon molten steel into the converter, and then adding the molten steel to a preset loading amount to ensure that the silicon content of the molten steel in the converter is less than or equal to 1.0 percent, wherein the adding amount of the converter is as follows according to the silicon content of the returned high-silicon molten steel:
the silicon content of the returned high-silicon steel water is less than or equal to 2 percent, and 1/2 furnace-returned high-silicon steel water is added into the converter;
the silicon content of the recycled high-silicon steel water is less than 3 percent and more than 2 percent, and the recycled high-silicon steel water of which the ratio is less than or equal to 1/3 is added into the converter;
the silicon content of the returned high-silicon steel water is more than or equal to 3 percent, and the returned high-silicon steel water which is less than or equal to 1/4 percent is added into the converter;
2) slagging control
The converter adopts a double-slag smelting method, and the added slagging material comprises active lime, dolomite, light-burned dolomite and sinter; the total amount of the added sinter is [ (molten iron temperature-1300) + (molten steel silicon content/n-0.3) × 200+180 ]/20; unit: t; n is the molten steel adding frequency;
a. controlling slag charge before slag discharge: adding amount of active lime: 15 plus or minus 0.5 kg/t; the addition amount of dolomite and light-burned dolomite: 15 plus or minus 0.5 kg/t; adding amount of sinter: the total amount of the added sinter is 1 plus or minus 0.5 t; blowing for 30s, and adding the mixture in two batches;
b. controlling slag charge after slag discharge: adding amount of active lime: 25 plus or minus 0.5 kg/t; the addition amount of dolomite and light-burned dolomite: 5 plus or minus 0.5 kg/t; the addition amount of the sintering ore is the total addition amount of the sintering ore, namely the amount of the sintering ore added before slag discharge;
3) gun position control
a. Opening a blowing gun: 2600mm-2700mm, open oxygen blast pressure: 0.9MPa to 1.05MPa, and the oxygen blowing flow rate is 53700 +/-50 Nm3H; blowing for 1min +/-30 s until the position of the gun is lowered to 2400 +/-10 mm, blowing for 2min +/-30 s until the position of the gun is lowered to 2200 +/-10 mm, blowing for 3min +/-30 s, lifting the position of the gun to 2600 +/-10 mm, blowing for 4min +/-30 s until the position of the gun is raised to 3000 +/-10 mm, and then waiting for 5min +/-30 s to lift the gun and discharge slag;
b. blowing again after slag discharging, and opening a blowing gun position: 2600 + -10 mm, oxygen flow 48000 + -50 Nm3H, after the fire is successfully struck, the position of the gun is lifted to 2800 +/-10 mm, and the oxygen blowing flow is adjusted to 53700 +/-50 Nm3/h；
4) Endpoint control
And measuring TSC by using a sublance when the oxygen is accumulated to 83-85%, blowing to a molten steel target component and a target temperature according to TSC measurement data, then lifting the sublance, and tapping.
The melting-back high-silicon steel water comprises FJACT, FJACT-1, FJACT-2, 50AW470, 50AW800, 50AW1300, 50AW600, AW800R and DY 015-03K.
Compared with the prior art, the invention has the beneficial effects that:
the method realizes the smelting and returning of the converter to the high-silicon steel water through the loading control, slagging control, lance position control and end point control of the converter. The aim of normal smelting of the converter is achieved, and the stable control of the converter smelting return high-silicon steel water is realized. The economic loss of a steel mill is reduced, and the accident rate of steel-making production is reduced. The operation rate of steel-making production is improved.
Detailed Description
The invention is further illustrated by the following examples:
the following examples describe the invention in detail. These examples are merely illustrative of the best embodiments of the present invention and do not limit the scope of the invention.
Examples
The method for smelting and returning high-silicon molten steel by the converter comprises the following process routes: the method comprises the following steps of (1) remelting high-silicon steel water → a converter → an argon station → refining → a casting machine, smelting steel species SPHC, and loading the converter with 270 tons, wherein the method comprises the following steps:
1) a new D-grade steel ladle is used during tapping, and the turnover time is less than or equal to 100 min;
2) adding molten iron except the returning high-silicon steel water, wherein the temperature of the molten iron is 1284 ℃, and the silicon content is 0.32%;
3) the target tapping temperature of the converter is 1665 ℃, and the P of the finished product is required to be less than or equal to 0.020%;
4) the silicon content of the high silicon steel water is 2.9 percent, the amount of the high silicon steel water added into the converter for returning is 90 tons, and the amount of the iron water added is 180 tons;
5) after the high silicon steel water and the molten iron are added, oxygen is blown by a lower lance, and the lance position is opened: 2600mm-2700mm, open oxygen blast pressure: 0.9-1.05 Mpa, and oxygen blowing flow rate of 53700Nm3Adding 3000kg of active lime, 3000kg of dolomite and 500kg of light burned dolomite after successful ignition, lowering the gun position to 2400mm in blowing for 1min, adding 3000kg of sinter, lowering the gun position to 2200mm in blowing for 2min, simultaneously adding 1000kg of second batch of active lime and 500kg of light burned dolomite, lifting the gun position to 2600mm in blowing for 3min, lifting the gun position to 3000mm in blowing for 4min, adding 1000kg of sinter during the period, and waiting for 5min and 30s to lift the gun and discharge slag;
6) blowing again after slag discharging, and opening a blowing gun position: 2600mm, oxygen flow 48000Nm3H, after the fire is successfully struck, the gun position is lifted to 2800mm, and the oxygen blowing flow is adjusted to 53700Nm3Adding 7000kg of active lime, 1000kg of dolomite and 500kg of light-burned dolomite into the mixture, adding 13800kg of residual sinter, and calculating according to automation until oxygen accumulation reaches 9500Nm3Carrying out TSC test through a sublance, blowing to a terminal point through TSC measurement data, and lifting the sublance; tapping at the end point temperature of 1663 ℃, the oxygen value of 503ppm and the end point P of 0.0163 percent;
7) after the steel is discharged, refining, and putting the steel on a machine for casting if the refining treatment is qualified;
8) and (4) continuously adding the residual recycled high-silicon steel water into two different furnaces for 2 times, and repeating the steps 4) -7) for converting and casting.