Molten steel continuous casting equipment and continuous casting method
Technical Field
The invention relates to the technical field of molten steel continuous casting, in particular to equipment for molten steel continuous casting and a continuous casting method thereof.
Background
Along with the stricter and stricter requirements on the quality of steel grades, the cleanliness of continuous casting billets is also more and more required, wherein the pollution degree of the continuous casting billets is mainly determined by the secondary oxidation degree of molten steel. If no good protective pouring measures are taken, the molten steel inevitably contacts with air during pouring, secondary oxidation is caused, and the quality of steel grades and the yield of alloy elements in the steel are influenced.
At present, equipment for continuous casting of molten steel mainly comprises a tundish and a ladle, wherein the ladle is positioned above the tundish, and a long nozzle communicated with the interior of the ladle is arranged on the bottom surface of the ladle.
In order to prevent the contact between molten steel from a ladle to a tundish and air, a conventional method is to use a ladle long nozzle with an argon blowing groove to enable the ladle long nozzle to be in meshed connection with a ladle down nozzle. Argon is blown into the joint to form an argon gas curtain, so that air is prevented from entering the joint, and a certain casting protection effect is achieved. However, by using the method, before the ladle is filled into the long nozzle, the cold steel in the ladle long nozzle bowl needs to be cleaned by using oxygen in each furnace, so that the pouring rhythm is influenced, and the labor intensity of workers is high; the ladle and the long nozzle are required to be aligned when being connected, the squareness and the straightness of the long nozzle and the perpendicularity of the molten steel surface are ensured in the pouring process, the ladle is rapidly descended after pouring, and the long nozzle is inserted into the liquid surface of the tundish to pour. The requirement on the operation of workers is high, the long nozzle is very easy to incline, and the bowl generates a gap to suck air to cause secondary oxidation of molten steel. When the number of continuous casting furnaces is too large, a joint of a long nozzle and a molten steel slag line is perforated, and the molten steel is seriously oxidized to cause continuous casting billet waste judgment.
Therefore, it is an urgent need to solve the above problems by developing a novel apparatus and method for continuous casting of molten steel.
Disclosure of Invention
In view of the above, the invention provides equipment and a continuous casting method for molten steel continuous casting, which are used for solving the problems that the conventional molten steel continuous casting equipment has high secondary oxidation degree, influences the quality of steel grades, and influences the pouring rhythm because a long water gap in a ladle needs to be continuously cleaned, the labor intensity of workers is high, and the like.
In one aspect, the present invention provides an apparatus for continuously casting molten steel, comprising: a tundish, a steel ladle and a non-oxidation immersion cover;
the tundish comprises: the tundish comprises a tundish body and a tundish cover body;
the upper end of the tundish body is open, and the bottom surface of the tundish body is provided with an immersion type water gap communicated with the inner cavity of the tundish body;
the tundish cover body is mounted at an upper end opening of the tundish body in a sealing manner, a mounting hole is formed in the center of the tundish cover body, and an air inlet and an air outlet are respectively formed in two sides of the tundish cover body;
the ladle is positioned above the tundish, and a ladle drainage port which extends downwards and is communicated with the interior of the ladle is arranged on the bottom surface of the ladle;
a pouring channel which runs through the upper end and the lower end is arranged in the non-oxidation immersion cover, a passage which is communicated with the pouring channel is arranged on the side wall of the upper part of the non-oxidation immersion cover, and an argon blowing pipe is arranged in the passage;
the non-oxidation immersion cover is arranged between the tundish and the ladle, the upper end of the non-oxidation immersion cover is sleeved outside a ladle drain port in the ladle, and the lower end of the non-oxidation immersion cover is inserted in a mounting hole of the tundish cover body and is positioned in the tundish.
Preferably, the non-oxidizing immersion hood is made of a refractory material.
Further preferably, a lower end of the non-oxidizing immersion hood located in the tundish is made of a magnesium refractory.
Further preferably, the upper portion of the non-oxidizing immersion hood has a frustum shape.
The invention also provides a molten steel continuous casting method, which is suitable for any equipment for continuous casting of molten steel, and the molten steel continuous casting method specifically comprises the following steps:
1) introducing argon into the tundish through an air inlet in the tundish, and replacing air in the tundish from an air outlet in the tundish;
2) and filling argon into the non-oxidation immersion cover through an argon blowing pipe, opening a ladle water outlet in the ladle, pouring molten steel into the tundish through the non-oxidation immersion cover, and injecting the molten steel into the crystallizer through the immersion water outlet in the ladle for molding.
The equipment for continuous casting of molten steel provided by the invention replaces the long nozzle in the conventional steel ladle with the non-oxidation immersion cover, so that the molten steel flow from the steel ladle to the tundish is protected from contacting with air to generate secondary oxidation, and a slag-free oxygen-free area filled with argon is formed in the non-oxidation immersion cover by inserting the non-oxidation immersion cover into the tundish and blowing the argon into the non-oxidation immersion cover, so that conditions are provided for preventing secondary oxidation of the molten steel, the quality of steel is improved, and meanwhile, the structure of the long nozzle is cancelled by arranging the non-oxidation immersion cover, so that the problems that the long nozzle needs to be continuously cleaned, the pouring rhythm is influenced, the labor intensity of workers is high and the like are effectively solved.
The equipment for continuous casting of molten steel provided by the invention has the advantages of simple structure, reasonable design, convenience in use, low secondary oxidation degree of molten steel pouring, high quality of the prepared steel grade and the like, and the equipment does not need to clean a long nozzle and has low labor intensity of workers.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an apparatus for continuous casting of molten steel according to an embodiment of the present disclosure.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.
The method aims to solve the problem that a ladle long nozzle with an argon blowing groove is used in the traditional method, and the ladle long nozzle and a ladle lower nozzle are in meshed connection. Particularly, argon is blown into the joint of the ladle long nozzle and the ladle lower nozzle to form an argon gas curtain, so that air is prevented from entering, and a certain pouring protection effect is achieved. However, by using the method, before the ladle is filled into the long nozzle, the cold steel in the ladle long nozzle bowl needs to be cleaned by using oxygen in each furnace, so that the pouring rhythm is influenced, and the labor intensity of workers is high; the ladle and the long nozzle are required to be aligned when being connected, the squareness and the straightness of the long nozzle and the perpendicularity of the molten steel surface are ensured in the pouring process, the ladle is rapidly descended after pouring, and the long nozzle is inserted into the liquid surface of the tundish to pour. The requirement on the operation of workers is high, the long nozzle is very easy to incline, and the bowl generates a gap to suck air to cause secondary oxidation of molten steel. When the number of continuous casting furnaces is too large, a joint of a long nozzle and a molten steel slag line is perforated, and the molten steel is seriously oxidized to cause continuous casting billet waste judgment. Therefore, the present embodiment improves the concrete structure of the apparatus for continuous casting of molten steel, specifically, the structure of the ladle shroud in the conventional apparatus for continuous casting of molten steel is eliminated, and instead, an oxidation-free immersion cover is added, and referring to fig. 1, the apparatus for continuous casting of molten steel is mainly composed of a tundish 1, a ladle 2 and an oxidation-free immersion cover 3, wherein the tundish 1 is composed of a tundish body 11 and a tundish cover 12, and the upper end of the tundish body 11 is open, a submerged nozzle 111 communicating with the inner cavity of the tundish body 11 is provided on the bottom surface of the tundish body 11, when in use, the submerged nozzle 111 communicates with the mold, the tundish cover 12 is sealed and installed on the open upper end of the tundish body 11, and a mounting hole is provided in the center of the tundish cover 12, and an air inlet 121 and an air outlet 122 are respectively provided on both sides of the tundish cover 12, the ladle 2 is located the top of middle package 1, and be provided with the ladle down mouth of a river 21 that downwardly extending just communicates with ladle 2 inside in the bottom surface of ladle 2, be provided with the pouring channel who link up both ends about not having the oxidation and dip in and cover 3, be provided with the passageway with the pouring channel intercommunication at the upper portion lateral wall that does not have the oxidation and dip in cover 3, be provided with in the passageway and blow argon pipe 31, it sets up between middle package 1 and ladle 2 not to have the oxidation and dip in cover 3, the outside of mouth of a river 21 under the ladle 2 is adorned to the upper end suit of not having the oxidation and dip in cover 3, the lower extreme that does not have the oxidation and dip in cover 3 is inserted and is located the.
The method for pouring molten steel by using the equipment for continuous casting of molten steel in the embodiment comprises the following specific steps:
1) introducing argon into the tundish 1 through an air inlet 121 in the tundish 1, and replacing air in the tundish 1 from an air outlet 122 in the tundish 1;
2) after argon gas is filled into the non-oxidation immersion cover 3 through the argon blowing pipe 31, the ladle down nozzle 21 in the ladle 2 is opened, molten steel is poured into the tundish 1 through the non-oxidation immersion cover 3, and then the molten steel is poured into the crystallizer through the submerged nozzle 111 in the ladle 1 for molding.
In the process of pouring, argon is filled into the non-oxidation immersion cover 3 through the argon blowing pipe 31, a slag-free oxygen-free area filled with argon is formed in the non-oxidation immersion cover 3, the argon protection space in the non-oxidation immersion cover provides conditions for preventing secondary oxidation of molten steel, and the protection mode of the non-oxidation immersion cover provides convenience for replacing a pouring ladle.
The equipment for continuous casting of molten steel provided by the embodiment can solve the problem of secondary oxidation of molten steel in the process of pouring the ladle, avoids the problem of cleaning a long nozzle because the long nozzle is not used any more, and reduces the labor intensity of workers.
In order to prolong the service life of the non-oxidation immersion hood 3 in the equipment for continuous casting of molten steel, as an improvement of the technical scheme, the non-oxidation immersion hood 3 is made of refractory materials; more preferably, the lower end of the non-oxidizing immersion hood 3 located in the tundish 1 is made of a magnesium refractory.
In order to save materials, the upper part of the conical non-oxidizing immersion hood 3 is designed into a frustum-shaped structure.
Experiments prove that the yield of the alloy elements in the steel billet cast by the equipment for continuous casting of the molten steel is improved, and the quality of the steel billet is effectively improved.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.