CN116511436A - A device and method for hydrating steel in a tundish for smelting rare earth steel - Google Patents

Abstract

The invention provides a device and a method for alloying molten steel in a tundish for smelting rare earth steel. The device comprises a material conveying pipeline for adding alloy for alloying; the material conveying pipeline adopts inert gas to carry out atmosphere protection, and one end of the material conveying pipeline directly goes deep into the interior of the tundish molten pool and is not contacted with the tundish surface covering agent; the pipeline bracket is used for supporting the material conveying pipeline and is arranged at one side of the molten steel tank; and a gas supply device for supplying inert gas. The invention also discloses a smelting method of the device, which comprises the steps of firstly roasting and preheating a material conveying pipeline; then one end of the material conveying pipeline extends below the liquid level of the tundish molten pool; and starting the gas supply device, keeping the inert gas continuously introduced for a certain time, and adding the rare earth alloy into the molten steel of the tundish at a certain feeding speed by adopting the feeder until the smelting of the rare earth steel is completed. The rare earth steel alloying is carried out by adopting the invention, the casting process has good castability, and the rare earth element yield can reach more than 50 percent.

Description

A device and method for hydrating steel in a tundish for smelting rare earth steel

technical field

The invention relates to the technical field of iron and steel metallurgy, in particular to a device and method for hydrating steel in a tundish for smelting rare earth steel.

Background technique

Rare earth steel has strong corrosion resistance and good machinability. The production scale of rare earth steel produced by traditional die casting process is small, and the production cost is high, so it is difficult to meet market demand.

In the existing technology, in the process of producing rare earth steel by continuous casting technology, because the rare earth elements are extremely active, they are easy to chemically react with free oxygen, sulfur and various oxides in the steel to form rare earth aluminates, rare earth oxides and other substances in the molten steel. Nodules are formed near the nozzle of the tank and the long nozzle, which affects the smooth progress of the pouring process. Moreover, the various rare earth compounds formed lead to a very low yield of rare earth elements in rare earth steels. Generally speaking, it is difficult for the yield of rare earths to exceed 20% when producing rare earth steels.

The addition method of rare earth alloy is a key process that affects the yield of rare earth alloy and the pouring process, so it is urgent to invent a device and method that can ensure the yield of rare earth alloy and effectively control the problem of nozzle nodules in the casting process of rare earth steel.

Contents of the invention

According to the above-mentioned technical problems of nozzle nodulation and low rare earth metal yield in the continuous casting process of rare earth steel, a device and method for smelting rare earth steel tundish steel water alloying are provided. In the present invention, the rare earth alloy is directly fed into the molten pool of the tundish by setting up the material conveying pipeline without contacting with the air or the surface covering agent of the tundish, so that the alloying process of the rare earth steel can be continuously The casting process has good castability, and the recovery rate of rare earth elements can reach more than 50%.

The technical means adopted in the present invention are as follows:

A device for smelting rare earth steel tundish steel water alloying, characterized in that it includes:

The material conveying pipeline is used to add alloys for alloying; the material conveying pipeline adopts inert gas for atmosphere protection, and one end of the material conveying pipeline directly penetrates into the tundish molten pool without contacting the tundish surface covering agent ;

a pipeline support, arranged on one side of the molten steel tank, for supporting the material conveying pipeline;

Gas supply device for supplying inert gas.

Further, the material conveying pipeline is made of aluminum-carbon refractory material.

Further, the inert gas is industrial pure argon.

The present invention also provides a method for smelting rare earth steel tundish steel water alloying using the above-mentioned device, which is characterized in that it includes the following steps:

S1. Before use, preheat the material conveying pipeline by baking;

S2, extending one end of the material conveying pipeline below the liquid level of the tundish molten pool;

S3. Turn on the gas supply device, keep the inert gas flowing in continuously, and after ensuring a certain inert gas feeding time, use a feeder to add the rare earth alloy into the molten steel in the tundish at a certain rate until the rare earth steel is completed. smelting.

Further, in step S3, before the rare earth alloy is added, the inert gas is kept flowing for 3 minutes to 5 minutes.

Further, in step S3, the adding rate of the rare earth alloy is matched with the amount of passing steel, satisfying the following relationship:

Among them, Q is the amount of steel passed through the continuous casting machine, t/min; Q _a is the alloy addition rate, kg/min; ω is the target value of rare earth content in the rare earth steel produced, wt.%; ω _a is the content of rare earth elements in the alloy , wt.%; R is the empirical yield of rare earth alloys, %.

Further, in step S3, the rare earth content in the rare earth alloy is 10wt.%-50wt.%.

Further, in step S3, the experimental yield of the rare earth alloy is 40%-60%.

Further, in step S3, the rare earth alloy is in the form of a rare earth cored wire or a block with uniform particle size.

Further, in step S3, before alloying the molten steel, the free oxygen content in the molten steel is lower than 0.001wt.%, the sulfur content is lower than 0.0016wt.%, and the total aluminum content is lower than 0.03wt.%.

Compared with the prior art, the present invention adopts the method of material conveying pipeline, and adds the rare earth alloy into the molten steel in the tundish according to the preset content and adding rate, which can effectively avoid rare earth oxidation during the adding process; at the same time, By controlling the addition rate and rare earth content, and matching the oxygen, sulfur and aluminum content in molten steel, the rare earth steel is alloyed to achieve good castability in the continuous casting process, and the recovery rate of rare earth elements can reach more than 50%.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a device for alloying molten steel in a tundish for smelting rare earth steel according to the present invention.

In the figure: 1. Material conveying pipeline; 2. Tundish; 3. Covering agent; 4. Liquid steel; 5. Pipe support.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is only some embodiments of the present invention, but not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that the terminology used here is only for describing specific embodiments, and is not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

The relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. At the same time, it should be clear that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized description. In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that like numbers and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

In the description of the present invention, it should be understood that orientation words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" etc. indicate the orientation Or positional relationship is generally based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. In the absence of a contrary statement, these orientation words do not indicate or imply the device or element referred to. It must have a specific orientation or be constructed and operated in a specific orientation, so it should not be construed as limiting the scope of the present invention: the orientation words "inside and outside" refer to inside and outside relative to the outline of each part itself.

For the convenience of description, spatially relative terms may be used here, such as "on ...", "over ...", "on the surface of ...", "above", etc., to describe the The spatial positional relationship between one device or feature shown and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, devices described as "above" or "above" other devices or configurations would then be oriented "beneath" or "above" the other devices or configurations. its underlying device or construction". Thus, the exemplary term "above" can encompass both an orientation of "above" and "beneath". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

As shown in Figure 1, the present invention provides a device for smelting rare earth steel tundish steel water alloying, specifically comprising:

The material conveying pipeline 1 is used to add alloys for alloying; the material conveying pipeline 1 adopts inert gas for atmosphere protection, and one end of the material conveying pipeline directly penetrates into the molten pool of the tundish 2 without contact with the surface of the tundish The covering agent is in contact with 3; the material conveying pipeline 1 is made of aluminum-carbon refractory material.

Pipe support 5, arranged on one side of the molten steel tank, for supporting the material conveying pipeline 1;

The gas supply device is used to provide inert gas, and the inert gas is industrial pure argon.

The present invention also provides a method for smelting rare earth steel tundish steel water alloying with the above-mentioned device, comprising the following steps:

S1. Before use, preheat the material conveying pipeline 1 by baking;

S2, extending one end of the material delivery pipeline 1 below the liquid level of the molten pool of the tundish 2;

S3. Turn on the gas supply device, keep the inert gas flowing in continuously, after ensuring a certain inert gas feeding time, keep the inert gas feeding time for 3min-5min, and use the feeder to add the rare earth alloy at a certain rate in the molten steel 4 in the tundish until the smelting of rare earth steel is completed.

The addition rate of the rare earth alloy is matched with the amount of passing steel, and the following relationship is satisfied:

Among them, Q is the amount of steel passed through the continuous casting machine, t/min; Q _a is the alloy addition rate, kg/min; ω is the target value of rare earth content in the rare earth steel produced, wt.%; ω _a is the content of rare earth elements in the alloy , wt.%; R is the empirical yield of rare earth alloys, %.

The rare earth content in the rare earth alloy is 10wt.%-50wt.%.

The experimental yield of the rare earth alloy is 40%-60%.

The rare earth alloy is in the form of a rare earth cored wire or a block with uniform particle size.

Before the molten steel is alloyed, the free oxygen content in the molten steel is lower than 0.001wt.%, the sulfur content is lower than 0.0016wt.%, and the total aluminum content is lower than 0.03wt.%.

Example 1

The total amount of molten steel is 206t, and the rare earth alloy is a rare earth iron alloy with a rare earth metal content of 38.8wt.%. The total aluminum content is 0.019wt.%;

Step 1: before use, preheat the material conveying pipeline 1 by baking;

Step 2: extending one end of the material delivery pipeline 1 below the liquid level of the molten pool of the tundish 2;

Step 3: Open the gas supply device, keep inert and continue to feed in; 3 minutes after the inert gas is fed in, the steel flow rate of the casting machine is 7.17t/min, the target rare earth content of rare earth steel is 150ppm, and the empirical yield is calculated according to 60% , the obtained alloy addition rate is 4.62kg/min, and the rare earth alloy is added into the tundish 2 at a feeding rate of 4.62kg/min by a feeder;

After completing the rare earth alloying process, the content of rare earth elements in molten steel 4 was detected to be 169ppm, the total amount of rare earth alloys added was 132kg, and the yield of rare earth metals was 63.6%.

Example 2

The total amount of molten steel is 205t, and the rare earth alloy is selected as a rare earth iron alloy with a rare earth metal content of 21wt.%. The aluminum content is 0.018wt.%;

The difference from Step 3 in Example 1 is that after the inert gas is introduced for 3 minutes, the steel passing rate of the casting machine is 7.8t/min, the target rare earth content of the rare earth steel is 100ppm, and the empirical yield is calculated according to 50%, and the alloy addition rate is obtained It is 7.42kg/min, and the rare earth alloy is added into the tundish 2 at a feeding rate of 7.42kg/min by a feeder;

After completing the rare earth alloying process, the content of rare earth elements in molten steel 4 was detected to be 104 ppm, the total amount of rare earth alloys added was 195 kg, and the yield of rare earth metals was 52%.

Example 3

The total amount of molten steel is 208t, and the rare earth alloy is selected as a rare earth iron alloy with a rare earth metal content of 19wt.%. The aluminum content is 0.0205wt.%;

The difference from step 3 in Example 1 is that after the inert gas is fed for 5 minutes, the steel passing through the casting machine is 6.4t/min, the target rare earth content of the rare earth steel is 150ppm, and the empirical yield is calculated according to 55%, and the alloy addition rate is obtained is 9.18kg/min, the rare earth alloy is added into the tundish 2 at a feeding rate of 9.18kg/min by a feeder;

After completing the rare earth alloying process, the content of rare earth elements in molten steel 4 was detected to be 152ppm, the total amount of rare earth alloys added was 298kg, and the yield of rare earth metals was 55.7%.

Example 4

The total amount of molten steel is 201t, and the rare earth alloy is selected as a rare earth iron alloy with a rare earth metal content of 18.5wt.%. The total aluminum content is 0.018wt.%;

The difference from step 3 in Example 1 is that after the inert gas is introduced for 4 minutes, the steel passing through the casting machine is 5.93t/min, the target rare earth content of the rare earth steel is 50ppm, and the empirical yield is calculated according to 55%, and the alloy addition rate is obtained is 2.91kg/min, and the rare earth alloy is fed into the tundish at a feeding rate of 2.91kg/min by a feeder;

After completing the rare earth alloying process, the content of rare earth elements in molten steel 4 was detected to be 51ppm, the total amount of rare earth alloys added was 98.7kg, and the yield of rare earth metals was 56.1%.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. A device for alloying molten steel in a tundish for smelting rare earth steel, which is characterized by comprising:

the material conveying pipeline is used for adding alloy for alloying; the material conveying pipeline adopts inert gas to be introduced for atmosphere protection, and one end of the material conveying pipeline directly penetrates into the tundish molten pool and is not contacted with the tundish surface covering agent;

the pipeline bracket is arranged on one side of the molten steel tank and is used for supporting the material conveying pipeline;

and the gas supply device is used for supplying inert gas.

2. The apparatus for alloying molten steel in a tundish for smelting rare earth steel according to claim 1, wherein said material conveying pipe is made of an aluminum-carbon refractory material.

3. The apparatus for alloying molten steel in a tundish for smelting rare earth steel according to claim 1, wherein said inert gas is commercially pure argon.

4. A method of alloying molten steel in a rare earth steel tundish using an apparatus as claimed in any one of claims 1 to 3, comprising the steps of:

s1, before use, baking and preheating the material conveying pipeline;

s2, extending one end of the material conveying pipeline below the liquid level of a tundish molten pool;

s3, starting the gas supply device, keeping the continuous introduction of inert gas, and adding rare earth alloy into molten steel of the tundish by adopting a feeder at a certain adding rate after ensuring a certain inert gas introduction time until the smelting of the rare earth steel is completed.

5. The method according to claim 4, wherein in step S3, the inert gas is kept for 3 to 5 minutes before the rare earth alloy is added.

6. The method according to claim 4, wherein in step S3, the rare earth alloy addition rate is matched with the steel flux, satisfying the following relationship:

wherein Q is the steel flux of the continuous casting machine, and t/min; q (Q) _a The alloy addition rate is kg/min; omega is the target value of the rare earth content in the produced rare earth steel, and wt.%; omega _a Is the content of rare earth elements in the alloy, wt.%; r is the acceptance rate of the rare earth alloy,%.

7. The method according to claim 4, wherein in step S3, the rare earth content in the rare earth alloy is 10wt.% to 50wt.%.

8. The method of claim 4, wherein in step S3, the rare earth alloy is inspected to have a yield of 40% to 60%.

9. The method according to claim 4, wherein in step S3, the rare earth alloy is a rare earth cored wire or a block with uniform particle size.

10. The method of claim 4, wherein in step S3, the molten steel has a free oxygen content of less than 0.001wt.%, a sulfur content of less than 0.0016wt.%, and a total aluminum content of less than 0.03wt.% prior to alloying.