A method for stabilizing arc buried in refining furnace electrodes

Abstract

The present invention relates to a method for stabilizing the submerged arc of a refining furnace electrode, the method comprises the following steps: adjusting the flow rate of argon gas at the bottom of molten steel to reduce the creep of the steel liquid surface, the flow rate of argon gas at the bottom of molten steel being 30-120L / min, and the creep range of the argon gas aperture at the molten steel liquid surface being 80-160mm; adjusting the power supply state of the refining furnace from "automatic" to "manual", and lowering the voltage working curve to a low gear; using the electrode "total rise" control button to slightly adjust the three-phase electrode button upward, adjusting the arc flow to 10000-15000A, and the arc being normal and stable; slowly raising the voltage working curve to normal, and adjusting the power supply state from "manual" to "automatic". By controlling the fluctuation size of the molten steel liquid surface, manually adjusting the rise and fall of the electrode and other stable arcs in the power supply process, the temperature rise rate of the molten steel and the stability of the carbon content of the smelting are effectively guaranteed, and the quality of the smelted billet is ensured to meet the product requirements.

Description

Technical Field

[0001] The invention relates to the technical field of off-furnace refining in iron and steel metallurgy technology, and in particular to a method for stabilizing the buried arc of electrodes in a refining furnace. Background Art

[0002] The basicity of refined steel slag outside the furnace can be divided into low-basicity steel slag (R<1.80), medium-basicity steel slag (R=1.80-2.50) and high-basicity steel slag (R>2.50) according to its properties. Products with different characteristics have different requirements for basicity. When low-basicity smelting is used, the problem of unstable arc submergence in the refining furnace electrode often occurs. At this time, the temperature of the molten steel will rise slowly. At the same time, the unstable arc submergence will cause large fluctuations in the carbon content in the molten steel, which will seriously affect the smooth production and the stability of product quality. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the above problems, the present invention provides a method for stabilizing the electrode submerged arc in a refining furnace, which achieves the effect of stabilizing the electrode submerged arc without changing the refining slag system or adding additional equipment, thereby stabilizing the temperature increase rate and carbon addition amount of the molten steel.

[0005] (II) Technical solution

[0006] In order to solve the technical problem, the present invention provides a method for stabilizing the submerged arc of the refining furnace electrode, the method comprising:

[0007] (1) Adjust the argon flow rate of the bottom blowing of molten steel to reduce the creep of the molten steel surface. The bottom blowing argon flow rate is 30-120L / min, and the creep range of the argon hole on the molten steel surface is 80-160mm;

[0008] (2) Adjust the power supply status of the refining furnace from "automatic" to "manual" and reduce the voltage working curve to a low level;

[0009] (3) Use the electrode "total lift" control button to slightly adjust the three-phase electrode button upwards, and the three-phase electrode cannot come out of the refining slag surface;

[0010] (4) Manually adjust the three-phase electrodes of the refining furnace and adjust the arc current to 10000-15000A. The arc is normal and stable.

[0011] (5) Slowly raise the voltage operating curve to normal, and at the same time adjust the power supply status from "manual" to "automatic".

[0012] Beneficial effects of the present invention:

[0013] By controlling the fluctuation of the molten steel level and manually adjusting the arc of the stable power transmission process such as the rise and fall of the electrode, the temperature rise rate of the molten steel and the stability of the smelting carbon composition can be effectively guaranteed, ensuring that the quality of the smelted billet meets the product requirements. DETAILED DESCRIPTION

[0014] Example 1

[0015] The present application is described in detail below in conjunction with specific embodiments.

[0016] When smelting low-basicity refining slag system (R≤1.8), the arc voltage and arc current of the three-phase electrode are unstable. This embodiment provides a method for stabilizing the buried arc of the refining furnace electrode, which is:

[0017] (1) Adjust the argon flow rate of the bottom blowing of molten steel to reduce the creep of the molten steel surface. The argon flow rate of the bottom blowing was adjusted from 120L / min to 30L / min. The creep of the molten steel surface in the ladle was observed. The diameter of the argon hole of the molten steel was about 100mm.

[0018] (2) Adjust the power supply state of the refining furnace from "automatic" to "manual", and reduce the voltage working curve to a low level. In this embodiment, the voltage level is adjusted from level 8 to level 13;

[0019] (3) Use the electrode simultaneous lifting function to slightly lift the three-phase electrodes (A, B, C) at the same time, and manually adjust the current of the A-phase electrode to 10000-15000A; manually adjust the current of the B-phase electrode to 10000-15000A; manually adjust the current of the C-phase electrode to 10000-15000A;

[0020] (4) After the arc is normal and stable, adjust the voltage level from level 13 back to level 8, and adjust the power supply mode of the refining furnace from manual back to automatic.

[0021] The composition of the final refining slag is 38.44% CaO, 40.87% SiO2, 10.04% MgO, 0.44% TFe, R0.94, and the others are small amounts of alumina, titanium dioxide, phosphorus pentoxide, etc.

[0022] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for stabilizing the arc of a refining furnace electrode, characterized in that: The method is: (1) Adjust the argon flow rate of the bottom blowing of molten steel to reduce the creep of the molten steel surface. The bottom blowing argon flow rate is 30-120L / min, and the creep range of the argon hole on the molten steel surface is 80-160mm; (2) Adjust the power supply status of the refining furnace from "automatic" to "manual" and reduce the voltage working curve to a low level; (3) Use the electrode "total lift" control button to slightly adjust the three-phase electrode button upwards, and the three-phase electrode cannot come out of the refining slag surface; (4) Manually adjust the three-phase electrodes of the refining furnace and adjust the arc current to 10000-15000A. The arc is normal and stable. (5) Slowly raise the voltage operating curve to normal and adjust the power supply status from "manual" to "automatic".