阅读说明：本技术 一种钢水的rh深脱碳的方法 (RH deep decarburization method of molten steel ) 是由 李龙 王建 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种钢水的RH深脱碳的方法,包括以下步骤：a1)在RH真空处理设备上设置供应CO<Sub>2</Sub>-Ar混合气的吹氩管；a2)将RH真空处理设备插入装有钢水的钢水包,开启真空泵使得RH真空处理设备的真空抽至小于第一压力时,开始吹CO<Sub>2</Sub>-Ar混合气使得钢水循环；a3)真空泵使得RH真空处理设备的真空抽至小于第二压力时,开始停止供应CO<Sub>2</Sub>-Ar混合气且所述吹氩管开始供应第一气体使得钢水循环；a4)真空泵使得RH真空处理设备的真空抽至小于第三压力时,继续供应第一气体4-6min。本发明的钢水的RH深脱碳的方法在无氧枪喷入气体时可以实现终点碳含量13-17ppm或12-14ppm,冶炼时间缩短2-3min。(The invention discloses a method for RH deep decarburization of molten steel, which comprises the following steps: a1) CO supply is arranged on RH vacuum treatment equipment 2 -an argon blowing tube of Ar gas mixture; a2) inserting RH vacuum treatment equipment into a ladle filled with molten steel, starting a vacuum pump to ensure that the vacuum of the RH vacuum treatment equipment is pumped to be less than a first pressure, and starting blowing CO 2 -Ar gas mixture circulating molten steel; a3) the vacuum pump makes the RH vacuum processing equipment vacuumized to be less than the second pressure, and then the CO supply is stopped 2 -Ar mixed gas and the argon blowing tube starts supplying the first gas so that molten steel circulates; a4) and when the vacuum of the RH vacuum processing equipment is pumped to be lower than the third pressure by the vacuum pump, continuously supplying the first gas for 4-6 min. The RH deep decarburization method of the molten steel can realize the end point carbon content of 13-17ppm or 12-14ppm when the gas is sprayed by the oxygen-free gun, and the smelting time is shortened by 2-3 min.)

1. A method for RH deep decarburization of molten steel is characterized by comprising the following steps:

a1) CO supply is arranged on RH vacuum treatment equipment₂-an argon blowing tube of Ar gas mixture;

a2) inserting RH vacuum treatment equipment into a ladle filled with molten steel, starting a vacuum pump to ensure that the vacuum of the RH vacuum treatment equipment is pumped to be less than a first pressure, and starting blowing CO₂-Ar gas mixture circulating molten steel;

a3) the vacuum pump makes the RH vacuum processing equipment vacuumized to be less than the second pressure, and then the CO supply is stopped₂-Ar mixed gas and the argon blowing tube starts supplying the first gas so that molten steel circulates;

a4) and when the vacuum of the RH vacuum processing equipment is pumped to be lower than the third pressure by the vacuum pump, continuously supplying the first gas for 4-6 min.

2. The method for RH deep decarburization of molten steel of claim 1, wherein the first gas is Ar-H₂Mixed gas or Ar gas.

3. The method of RH deep decarburization of molten steel of claim 2, wherein Ar-H₂H in the mixed gas₂55 to 70 weight percent of Ar-H₂The air supply flow of the mixed gas is 0.7-1.2Nm³/h·t。

4. The method for RH deep decarburization of a molten steel as recited in claim 1, wherein the molten steel before being treated has a carbon content of 0.0035 wt.% to 0.045 wt.%, an oxygen content of 0.025 wt.% to 0.040 wt.%, and a temperature of 1650-1710 ℃.

5. The method for RH deep decarburization of molten steel of claim 1, wherein CO is introduced into the molten steel₂CO in-Ar gas mixture₂50-65 wt% of CO₂The flow rate of the-Ar mixture is 0.7-1.2Nm³/h·t。

6. The method for RH deep decarburization of molten steel according to claim 1, wherein the first pressure is 17 kPa.

7. The method for RH deep decarburization of molten steel according to claim 1, wherein the second pressure is 300 Pa.

8. The method for RH deep decarburization of molten steel according to claim 1, wherein the second pressure is 100 Pa.

Technical Field

The present invention relates to the field of metallurgy, and more particularly, to a method of RH deep decarburization of molten steel.

Background

In recent years, RH vacuum degassing equipment, and RH functions and steel types for refining have been expanded, and a multifunctional vacuum refining technology has been developed, and has been dominant in external refining. Most steel mills are provided with RH refining equipment, so that the high-efficiency and low-cost production of high-quality steel is realized.

Along with the requirement of the market on the carbon content of various steels, particularly the carbon content of finished products is within 15ppm or even 10ppm, in order to meet the requirement, RH adopts oxygen blowing to perform forced decarburization, the oxygen supply time needs to be prolonged, so that the oxygen activity of molten steel is higher, and the cleanliness of the molten steel is not favorable.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method for RH deep decarburization of molten steel.

Based on the purpose, the following technical scheme is adopted:

according to the present invention, there is provided a method for RH deep decarburization of molten steel, comprising the steps of:

a1) CO supply is arranged on RH vacuum treatment equipment₂-an argon blowing tube of Ar gas mixture;

a2) inserting RH vacuum treatment equipment into a ladle filled with molten steel, starting a vacuum pump to ensure that the vacuum of the RH vacuum treatment equipment is pumped to be less than a first pressure, and starting blowing CO₂-Ar gas mixture circulating molten steel;

a3) the vacuum pump makes the RH vacuum processing equipment vacuumized to be less than the second pressure, and then the CO supply is stopped₂-Ar gas mixture and the argon blowing tube starts to supply the first gasCirculating the molten steel;

a4) and when the vacuum of the RH vacuum processing equipment is pumped to be lower than the third pressure by the vacuum pump, continuously supplying the first gas for 4-6 min.

Further, the first gas is Ar-H₂Mixed gas or Ar gas.

Further, Ar-H₂H in the mixed gas₂55 to 70 weight percent of Ar-H₂The air supply flow of the mixed gas is 0.7-1.2Nm³/h·t。

Further, the carbon content of the molten steel before treatment is 0.0035 to 0.045 weight percent, the oxygen content is 0.025 to 0.040 weight percent, and the temperature is 1650-1710 ℃.

Further, CO₂CO in-Ar gas mixture₂50-65 wt% of CO₂The flow rate of the-Ar mixture is 0.7-1.2Nm³/h·t。

Further, the first pressure was 17 kPa.

Further, the second pressure is 300 Pa.

Further, the second pressure is 100 Pa.

The invention has the beneficial effects that:

the RH deep decarburization method of molten steel can realize 12-14ppm of end point carbon content (the first gas is Ar-H) when the gas is injected by an oxygen-free gun₂Mixed gas) or 13-17ppm (the first gas is Ar gas), the smelting time is shortened by 2-3 min; the good decarburization effect can be achieved and the smelting time is shortened under the condition of only adopting the argon blowing pipe for air intake; and only the argon blowing pipe is used for air inlet, so that the cost is further reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some implementation examples of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic view of an RH vacuum processing apparatus according to embodiments 1 to 4 of the present invention;

FIG. 2 is a schematic view of an argon blowing tube according to an embodiment of the present invention;

FIG. 3 is a schematic view of the projection of the argon blowing tube and the rising pipe to the horizontal plane according to the embodiment of the present invention.

List of reference numerals

1-steel ladle 2-vacuum degassing tank 3-tank body 4-downcomer 5-riser 8-argon blowing pipe 81-main pipe 82-first branch pipe 83-second branch pipe

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments of the present invention are described in further detail with reference to the accompanying drawings.