CN116103469B

CN116103469B - A method for increasing the service life of RH impregnated tubes

Info

Publication number: CN116103469B
Application number: CN202310175316.3A
Authority: CN
Inventors: 赵晨光; 崔国亮; 陈宇; 高洪涛; 金宏斌; 苏毅; 李西岱
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2023-02-27
Filing date: 2023-02-27
Publication date: 2025-04-22
Anticipated expiration: 2043-02-27
Also published as: CN116103469A

Abstract

The invention provides a method for prolonging the service life of an RH dip pipe, which comprises the following steps of S1, baking a prepared RH vacuum chamber twice in sequence to enable the temperature of the vacuum chamber to reach the production operation temperature, S2, after the temperature of the vacuum chamber reaches the production operation temperature, sequentially carrying out molten steel dipping, first spraying and first curing on the dip pipe, S3, carrying out second spraying and second curing on the dip pipe obtained in the step S2, and normally putting the dip pipe into production, S4, carrying out molten steel treatment around the dip pipe, namely putting lime into the production to increase the top slag alkalinity of a molten steel tank around the dip pipe so as to enable the top slag to become sticky, S5, after the molten steel treatment is finished, increasing the thickness of the wall of the dip pipe through the movement of the dip pipe at the molten steel liquid level, and S6, dynamically monitoring the thickness of the wall of the dip pipe so as to ensure the smooth production. The invention can prolong the service life of the RH dip pipe by 15 to 20 tanks.

Description

Method for prolonging service life of RH dip pipe

Technical Field

The invention relates to the technical field of external refining, in particular to a method for prolonging the service life of an RH dip pipe.

Background

In order to improve the service life of the RH dip pipe, the conventional operation of each steel factory basically carries out online or offline gunning on the dip pipe after continuous production for a certain time, and then carries out production after curing for a certain time. The conventional spray repair technology can improve the service life of the RH dip pipe, but the production conditions of all steel plants are quite different, and for steel plants with fast production pace and complex production steel types, the service life of the RH dip pipe is limited by simply spray repair, so that a new auxiliary method is necessary to be further researched, and the service life of the RH dip pipe is further improved.

Disclosure of Invention

According to the proposed steel plants, the production conditions are greatly different, and for steel plants with fast production rhythm and complex steel types, the service life of the RH dip pipe is prolonged by simply spraying and repairing, so that the method for prolonging the service life of the RH dip pipe is provided.

The invention adopts the following technical means:

A method for improving the service life of an RH-impregnated tube, comprising the steps of:

S1, baking the prepared RH vacuum chamber twice in sequence to enable the temperature of the vacuum chamber to reach the production operation temperature;

S2, after the temperature of the vacuum chamber reaches the production operation temperature, soaking the dipping pipe in molten steel, performing first spray repair and performing first health maintenance;

S3, carrying out second spray repair and second health maintenance on the dip pipe obtained in the step S2, and normally putting the dip pipe into production;

s4, during normal production, molten steel around the dip pipe is treated, wherein lime is added to increase the alkalinity of top slag of a molten steel tank around the dip pipe so as to make the top slag become sticky;

s5, after the molten steel treatment is finished, increasing the thickness of the pipe wall of the dipping pipe through the movement of the dipping pipe at the liquid level of the molten steel;

S6, dynamically monitoring the thickness of the pipe wall of the dip pipe, and ensuring the smooth production.

Further, in the step S1, the RH vacuum chamber is baked for the first time at the drying position, and after the on-line production condition is met, that is, the temperature of the vacuum chamber is not less than 900 ℃, the RH vacuum chamber is then lifted to the standby position to continue to bake for the second time, and the temperature of the RH vacuum chamber is ensured to be not less than 1100 ℃.

Further, the step S2 includes the steps of:

S21, when the temperature in the vacuum chamber reaches 1100 ℃ or above, moving the vacuum chamber to a treatment position, arranging a tank of molten steel to enter the treatment position, inserting a dipping pipe into the molten steel for first dipping, and pulling out after dipping for 1-2 min;

S22, inserting the dipping pipe into molten steel again for secondary dipping, and pulling out after dipping for 1-2 min;

s23, moving the vacuum chamber to a standby position, performing routine gunning on the dipping pipe for the first time, and preserving for 1.5 to 2 hours after the gunning is finished.

Further, in the step S3, after the first curing is finished, the production is stopped after 1 to 2 cans of molten steel are processed, the dip pipe is subjected to the second conventional spray repair, and after the spray repair is finished, the dip pipe is normally put into production after curing for 1.5 to 2 hours.

In the step S4, lime is prepared in advance for feeding when normally put into production, and lime is evenly fed into molten steel around the dip pipe in the RH normal production process, and the feeding total amount is controlled according to 100kg so as to increase the alkalinity of slag in a molten steel tank around the dip pipe and enable the slag to be sticky.

Further, in the step S5, after the molten steel treatment is finished, the dip tube is not immediately lifted from the molten steel liquid level, and the dip tube is repeatedly moved up and down at the molten steel liquid level twice by using the RH equipment lifting system, so that the thickened molten steel can top slag is hung on the outer wall of the dip tube as much as possible, and the thickness of the wall of the dip tube is increased.

Further, in the step S6, the thickness of the wall of the dip pipe is dynamically monitored, when the distance between the outer wall of the dip pipe and the inner wall of the molten steel tank is less than or equal to 100mm, the lime is stopped being put in, and the smooth production is ensured by carrying out deslagging operation on the wall of the dip pipe or reducing the conventional gunning amount.

Compared with the prior art, the invention has the following advantages:

The method for prolonging the service life of the RH dip pipe provided by the invention can prolong the service life of the RH dip pipe by 15 to 20 tanks.

In summary, the technical scheme of the invention can solve the problems that the production conditions of steel plants in the prior art are quite different, the production rhythm is fast, and the service life of the RH dip pipe is limited by simply depending on gunning for steel plants with complex steel types.

Based on the reasons, the method can be widely popularized in the fields of prolonging the service life of the RH dip pipe and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to the drawings without inventive effort to a person skilled in the art.

FIG. 1 is a flow chart of the method of the present invention.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

As shown in FIG. 1, the invention provides a method for prolonging the service life of an RH dip pipe, belongs to the technical field of external refining, and particularly improves the service life of the RH dip pipe by a special method.

The invention aims to further improve the service life of the RH dip pipe on the basis of the prior art.

The method for prolonging the service life of the RH dip pipe comprises the following steps:

and firstly, baking the newly prepared RH vacuum chamber at a drying position, wherein the RH vacuum chamber has on-line production conditions, namely, the temperature of the vacuum chamber is more than or equal to 900 ℃, and then, the RH vacuum chamber is hung to a standby position for continuous baking, and the temperature of the vacuum chamber is required to meet the requirement of more than or equal to 1100 ℃ for the secondary baking.

And step two, when the temperature in the vacuum chamber reaches 1100 ℃ or above, moving the vacuum chamber to a treatment position, and then arranging a tank of molten steel to enter the treatment position. The dipping pipe is inserted into molten steel, soaked for 1min and then pulled out, so as to remove the residual moisture in the dipping pipe body material in a steam form. Then the vacuum chamber is inserted into molten steel again, soaked for 1min and pulled out, and then the vacuum chamber is moved to a standby position for one-time conventional gunning. And after the spray repair is finished, preserving the health for 1.5 to 2 hours. The purpose of this operation is to strengthen the intensity of the dip pipe earlier stage, avoid using earlier stage body material to appear peeling off damage phenomenon under the molten steel thermal shock effect to reduce life.

And thirdly, after the curing in the second step is finished, the production is stopped after the 1 to 2 cans of molten steel are processed, and the conventional spray repair is performed again. After the gunning is finished, the production can be normally put into production after the health maintenance is carried out for 1.5 to 2 hours.

And step four, preparing a plurality of lime hands of 10 kg/bag in advance for feeding when the production is normally put into production, and carrying out molten steel treatment around the dip pipe. In the RH normal production process, lime is evenly added around the dip pipe (the total addition amount is controlled according to 100 kg), and the purpose is to increase the alkalinity of the top slag of the molten steel tank around the dip pipe, so that the top slag becomes sticky.

And fifthly, after the molten steel treatment is finished, the dipping pipe does not need to be lifted off the molten steel liquid surface immediately. The RH equipment jacking system is utilized to enable the dipping pipe to repeatedly move up and down at the liquid level of molten steel for two times, and the purpose is to enable the thickened molten steel tank top slag to be hung on the outer wall of the dipping pipe as much as possible, so that the thickness of the pipe wall of the dipping pipe is increased.

Step six, dynamically monitoring the thickness of the pipe wall of the dipping pipe, and if the tendency of rough scraping of the molten steel tank occurs, namely when the distance between the outer wall of the dipping pipe and the inner wall of the molten steel tank is less than or equal to 100mm, stopping pouring lime, and carrying out deslagging operation on the pipe wall of the dipping pipe or reducing the conventional gunning quantity, thereby ensuring smooth production.

By the method for prolonging the service life of the RH dip pipe, the service life of the RH dip pipe can be prolonged by 15 to 20 tanks.

The single ladle treatment capacity is 200 tons of molten steel tanks, and due to the compact treatment rhythm, the RH treated molten steel yield accounts for 65 percent of the total yield of two RH external refining furnaces, and the average service life of the RH dip pipe is 58.4 tanks. After the method for improving the service life of the dip pipe is implemented, the average service life of the RH dip pipe reaches 75 tanks. This demonstrates that the effect of the invention is significant for improving the service life of the RH dip pipe. Can be popularized and implemented.

It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. A method for increasing the service life of a RH immersion tube, comprising the following steps:

S1. Bake the prepared RH vacuum chamber twice to make the temperature of the vacuum chamber reach the production operating temperature;

S2. After the temperature of the vacuum chamber reaches the production operating temperature, the immersion tube is sequentially immersed in molten steel, sprayed for the first time, and cured for the first time;

S3, after the impregnated pipe obtained in step S2 is subjected to a second gunning repair and a second curing, it is put into normal production;

S4. When the production is put into normal operation, the molten steel around the immersion pipe is treated: lime is added to increase the basicity of the top slag of the molten steel tank around the immersion pipe, making the top slag viscous;

S5. After the molten steel treatment is completed, the wall thickness of the immersion tube is increased by moving the immersion tube at the molten steel liquid surface;

S6. Dynamically monitor the wall thickness of the immersion pipe to ensure smooth production;

In step S1, the RH vacuum chamber is first baked in the drying position, and after the production conditions are met, that is, the vacuum chamber temperature is ≥900°C, it is then hoisted to the standby position for the second baking, and the second baking ensures that the vacuum chamber temperature meets ≥1100°C;

The step S2 comprises the following steps:

S21. When the temperature in the vacuum chamber reaches 1100°C or above, move the vacuum chamber to the processing position, arrange a tank of molten steel to enter the processing position, insert the immersion tube into the molten steel for the first immersion, and pull it out after immersing for 1-2 minutes;

S22, insert the immersion tube into the molten steel again for a second immersion, and pull it out after soaking for 1-2 minutes;

S23, then move the vacuum chamber to the standby position, perform the first conventional gunning repair on the impregnated pipe, and after the gunning repair is completed, cure for 1.5 to 2 hours.

2. The method for increasing the service life of the RH immersion pipe according to claim 1 is characterized in that in the step S3, after the first curing is completed, the production is stopped after processing 1 to 2 tanks of molten steel, and the immersion pipe is subjected to a second conventional gunning repair. After the gunning repair is completed, the pipe is cured for 1.5 to 2 hours and then put into production normally.

3. The method for increasing the service life of the RH immersion tube according to claim 1 is characterized in that, in the step S4, when the production is put into normal operation, lime is prepared in advance; during the normal production process of RH, lime is evenly added to the molten steel around the immersion tube, and the total amount added is controlled at 100 kg to increase the basicity of the top slag of the molten steel tank around the immersion tube and make the top slag viscous.

4. The method for increasing the service life of the RH immersion tube according to claim 1 is characterized in that, in the step S5, after the molten steel treatment is completed, the immersion tube is not immediately lifted off the molten steel surface, and the RH equipment lifting system is used to repeatedly move the immersion tube up and down twice at the molten steel surface, so that the viscous molten steel tank top slag is hung on the outer wall of the immersion tube as much as possible to increase the wall thickness of the immersion tube.

5. The method for increasing the service life of the RH immersion tube according to claim 1 is characterized in that, in the step S6, the thickness of the immersion tube wall is dynamically monitored, and when the distance between the outer wall of the immersion tube and the inner wall of the molten steel tank is ≤100 mm, the addition of lime is stopped, and the slag removal operation is performed on the immersion tube wall, or the conventional gunning amount is reduced to ensure smooth production.