Tundish dry material for continuous casting of heavy rail and preparation method and application of tundish dry material

Abstract

The invention relates to the technical field of steel smelting, in particular to a tundish dry material for heavy rail continuous casting and a preparation method and application of the tundish dry material. The preparation method comprises the following steps: A, preparing materials according to the following formula in percentage by weight: 82%-83% of MgO, 2.5%-3.5% of Al2O3, 5%-8% of MgO-Al2O3, 1.0%-2.0% of CaO, 2.0%-2.5% of SiO2 and the balance of inevitable impurities; and B, sintering the ingredients in the step A to obtain the tundish dry material for continuous casting of the heavy rail. On the basis of determining the erosion behavior mechanism of the covering agent for continuous casting of the heavy rail steel to the dry material, the invention provides a method for reducing the erosion depth of the refractory material by controlling the permeability. According to the tundish dry material for continuous casting of the heavy rail, the refractory quality of the tundish dry material for continuous casting of the heavy rail steel can be improved, the average erosion rate of the tundish dry material is obviously reduced, and the increase of MgO in covering agent slag is obviously reduced.

Description

Technical Field

[0001] This invention relates to the field of iron and steel smelting technology, and in particular to a dry-type material for heavy rail continuous casting, its preparation method and application. Background Technology

[0002] Non-metallic inclusions typically hinder the continuity of the steel matrix, leading to significant anisotropy in the mechanical properties of the steel under load. They become traps for the diffusion of harmful gas elements, and under extreme conditions, can act as crack initiation sites or induce crack formation, ultimately resulting in a decline in the service performance of the steel. Specifically, as heterogeneous phases in the steel matrix, non-metallic inclusions significantly reduce the material's plasticity, toughness, and fatigue properties. Based on their morphological distribution, non-metallic inclusions can be broadly classified into four types: A (sulfides), B (alumina), C (silicates), D (spherical oxides), and Ds (large single-particle oxides). Among them, type A MnS inclusions extend along the rolling direction during high-temperature deformation, forming banded structures. During ductile fracture, cracks compete for space within cavities formed by inclusions of different types and morphologies. Cracks preferentially initiate at inclusions with poor adhesion to the matrix or where stress concentration is high, particularly near strip-shaped sulfides that reduce the transverse plasticity of the steel. Brittle inclusions such as Al2O3 or MgO-Al2O3 (Type B and D) can generate stress concentration factors 3-5 times that of the matrix under stress, thus becoming crack initiators, reducing the impact toughness of the steel, and inducing localized brittle fracture. Type C inclusions, often elongated glassy phases at room temperature and with acute-angled ends after rolling, easily form cracks at the inclusion-steel matrix interface, leading to performance degradation. Furthermore, inclusions also affect the corrosion resistance of steel. In environments with corrosive media, non-metallic inclusions easily form micro-galvanic cell structures with the steel matrix, leading to corrosion. In severe cases, this can form crack initiators and cause fatigue failure of the steel. Furthermore, non-metallic inclusions, acting as potential crack initiation sites and hydrogen traps, negatively impact the machinability, weldability, and hydrogen-induced delayed fracture of steel. Therefore, controlling non-metallic inclusions in steel has always been a core research focus in iron and steel metallurgy.

[0003] For heavy rail steel, the control requirements for non-metallic inclusions in the rails are extremely high, mainly because non-metallic inclusions have a significant impact on the service performance of rails under special service conditions. Regarding rail damage on heavy-haul lines, Tian Changhai et al.'s study, "Research on the Variation and Influencing Factors of 75kg / m Rail Damage on the Daqin Railway," based on statistics of rail damage rates at three time points in 2006, 2010, and 2016, concluded that the influencing factors of rail damage include rail strength, non-metallic inclusion grade, trace element control, welding, track structure, and maintenance. The main types of damage affecting rail service performance are: core damage caused by internal cracks or defects, tread damage caused by contact fatigue cracks (peeling cracks), surface defects, and corrosion. These damages can cause severe rail damage, and in severe cases, rail breakage. Among these, the typical damage caused by internal cracks or defects is of two types: hydrogen-induced cracking and longitudinal and transverse core damage at the rail head. Hydrogen-induced cracking has a low incidence rate due to the strict control of hydrogen content in steel by rail manufacturers. The formation of longitudinal and transverse core damage at the rail head is mainly related to strip-shaped inclusions inside the rail head. When coarse non-metallic inclusions distributed along the rail rolling direction exist in the wheel-rail contact stress influence zone within a depth of 5-12 mm below the rail head tread, strip-shaped crack initiation points will form. Longitudinal cracks, after initiating from these strip-shaped initiation points and developing to a certain stage, will then extend laterally, forming longitudinal and transverse core damage.

[0004] The steel smelting process is complex and affected by the single or combined effects of deoxidation, refining, refractory corrosion, and slag runoff and slag entrapment during continuous casting. Therefore, the control of inclusions requires meticulous control throughout the entire process.

[0005] Generally, deoxidation products in steelmaking can be effectively removed through bottom-blown argon, vacuum circulation, and adsorption by the refining slag system. The size of non-metallic inclusions in the refined molten steel is mostly less than 10 μm. Therefore, preventing secondary oxidation, refractory erosion, and slag carryover during continuous casting is crucial for maintaining high cleanliness of the molten steel. Studies have found that during continuous casting, the refractory material-dry slag line in the tundish working layer experiences significant erosion due to the erosion by the tundish covering agent, with a maximum erosion depth exceeding 20 mm. The main component of the dry slag is MgO. After being eroded by the covering agent slag, the MgO in the dry slag enters the covering agent slag and undergoes a high-temperature chemical reaction with Al2O3 in the slag, producing a magnesium-aluminum spinel phase, severely deteriorating the original metallurgical properties of the covering agent slag. This is mainly manifested in a significant change in the melting characteristics and physical properties of the covering agent slag, with the melting point increasing from 1400℃ to over 1560℃. Furthermore, under the casting temperature conditions, the proportion of liquid phase in the slag decreases from 99% to below 75%. This change significantly deteriorates the ability of the molten slag in the ladle to adsorb and remove non-metallic inclusions from the molten steel. Under the shear force at the steel-slag interface, inclusions are carried into the molten steel and ultimately remain in the billet, greatly deteriorating the cleanliness of heavy rail steel, significantly reducing the quality level of the rails, and adversely affecting rail production and track service. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a dry tundish material for heavy rail continuous casting, its preparation method and application. The dry tundish material for heavy rail continuous casting prepared by the present invention can improve the quality of refractory materials in the dry tundish material of heavy rail steel continuous casting, significantly reduce its average erosion rate and significantly reduce the increase of MgO in the covering agent slag.

[0007] This invention provides a method for preparing dry-mixed feedstock for heavy rail continuous casting, comprising the following steps:

[0008] A. Ingredients as per the following weight percentages:

[0009] MgO 82%~83%, Al2O3 2.5%~3.5%, MgO-Al2O3 5%~8%, CaO 1.0%~2.0%, SiO2 2.0%~2.5%, balance unavoidable impurities;

[0010] B. Sinter the ingredients from step A to obtain dry material for heavy rail continuous casting.

[0011] Preferably, the particle size distribution of the ingredients includes 5~3 mm, 3~1 mm and ≤1 mm.

[0012] Preferably, the particle size distribution of the ingredients comprises, by weight percentage:

[0013] Particles of 5-3 mm, and not exceeding 3 mm, comprise 10%-16%;

[0014] Particles ranging from 3 to 1 mm, and not exceeding 1 mm, account for 20% to 22%;

[0015] Particles ≤1mm account for 62%~70%;

[0016] The sum of the amounts of the components is 100%.

[0017] Preferably, among particles ≤1mm, the content of particles ≤0.05mm is 34%~39% by weight.

[0018] Preferably, the sintering process is as follows: heating at 9~11℃ / min to 550~650℃, then heating at 2~4℃ / min to 750~850℃, holding at that temperature for 1~3 h, then heating at 4~6℃ / min to 1150~1250℃, and finally heating at 2~4℃ / min to 1350~1450℃, holding at that temperature for 45~50 min.

[0019] Preferably, in step A, the ingredients include at least one of magnesia, corundum, magnesium aluminum spinel, quicklime, and silica powder.

[0020] The present invention also provides a dry ladle material for heavy rail continuous casting prepared by the method described above.

[0021] The present invention also provides an application of the dry-type material in the tundish used for heavy rail continuous casting described above in the heavy rail continuous casting process.

[0022] Preferably, the elemental composition of the molten steel in the continuous casting process of heavy rail steel is as follows, by weight percentage:

[0023] C 0.75%~0.82%, Si 0.10%~0.40%, Mn 0.90%~1.20%, P≤0.025%, S≤0.025%, Cr0.40%~0.50%, V 0.04%~0.06%, balance Fe and unavoidable impurities.

[0024] This invention, based on a clear understanding of the erosion mechanism of the covering agent used in continuous casting of heavy rail steel on dry refractory materials, proposes a method for controlling permeability to reduce the erosion depth of the refractory. The dry refractory material prepared by this invention for tundish continuous casting of heavy rail steel can improve the quality of the refractory material in the tundish, significantly reducing its average erosion rate and the increase in MgO in the covering agent slag. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a method for preparing dry-mixed feedstock for heavy rail continuous casting, comprising the following steps:

[0027] A. Ingredients as per the following weight percentages:

[0028] MgO 82%~83%, Al2O3 2.5%~3.5%, MgO-Al2O3 (magnesium aluminum spinel) 5%~8%, CaO 1.0%~2.0%, SiO2 2.0%~2.5%, balance unavoidable impurities;

[0029] B. Sinter the ingredients from step A to obtain dry material for heavy rail continuous casting.

[0030] Regarding step A:

[0031] Ingredients as per the following weight percentages:

[0032] MgO 82%~83%, Al2O3 2.5%~3.5%, MgO-Al2O3 (magnesium aluminum spinel) 5%~8%, CaO 1.0%~2.0%, SiO2 2.0%~2.5%, balance unavoidable impurities.

[0033] In some embodiments of the present invention, the raw materials used in the formulation are at least one selected from magnesia, corundum, fine powder of magnesium aluminum spinel, quicklime, and quartz sand. In some embodiments of the present invention, the raw materials used in the formulation are magnesia, corundum, fine powder of magnesium aluminum spinel, quicklime, and quartz sand. The magnesia is fused magnesia with an MgO content of 97.3% by mass. The corundum is white corundum with an Al2O3 content of 99% by mass. The quicklime contains 72% CaO by mass. The quartz sand contains 95% SiO2 by mass.

[0034] In some embodiments of the present invention, the particle size distribution of the ingredients includes 5~3 mm, 3~1 mm and ≤1 mm.

[0035] In some embodiments of the present invention, the particle size distribution of the ingredients comprises, by weight percentage:

[0036] Particles of 5-3 mm, and not exceeding 3 mm, comprise 10%-16%;

[0037] Particles ranging from 3 to 1 mm, and not exceeding 1 mm, account for 20% to 22%;

[0038] Particles ≤1mm account for 62%~70%;

[0039] The sum of the amounts of the components is 100%.

[0040] Specifically, the weight percentages of particles between 5 and 3 mm (and not 3 mm) are 16%, 12%, and 10%.

[0041] The weight percentages of particles ranging from 3 to 1 mm (and not 1 mm) are 22%, 21%, and 20%.

[0042] The weight percentage of particles ≤1mm is 62%, 67%, and 70%.

[0043] In some embodiments of the present invention, the content of particles ≤0.05mm in particles ≤1mm is 34% to 39% by weight; for example, 34%, 37%, 39%.

[0044] Regarding step B:

[0045] The ingredients in step A are sintered to obtain dry material for heavy rail continuous casting.

[0046] The sintering process is as follows: the temperature is increased to 550-650℃ at a rate of 9-11℃ / min, then increased to 750-850℃ at a rate of 2-4℃ / min, and held for 1-3 hours. Then the temperature is increased to 1150-1250℃ at a rate of 4-6℃ / min, and finally increased to 1350-1450℃ at a rate of 2-4℃ / min, and held for 45-50 minutes.

[0047] Specifically, the sintering process is as follows: the temperature is increased to 600℃ at 10℃ / min, then increased to 800℃ at 3℃ / min, held for 2 hours, then increased to 1200℃ at 5℃ / min, and finally increased to 1400℃ at 3℃ / min, held for 47 minutes.

[0048] The present invention also provides a dry ladle material for heavy rail continuous casting prepared by the method described above.

[0049] The present invention also provides an application of the aforementioned dry tundish material for heavy rail continuous casting in the heavy rail continuous casting process; specifically, the dry tundish material for heavy rail continuous casting is used as the refractory material (dry material) of the working layer of the tundish in the heavy rail continuous casting process.

[0050] In some embodiments of the present invention, the elemental composition of the molten steel in the continuous casting process of heavy rail steel is as follows, by weight percentage:

[0051] C 0.75%~0.82%, Si 0.10%~0.40%, Mn 0.90%~1.20%, P≤0.025%, S≤0.025%, Cr0.40%~0.50%, V 0.04%~0.06%, balance Fe and unavoidable impurities.

[0052] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes a dry-type material for heavy rail continuous casting, its preparation method, and its application, but this should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] Preparation of dry-mixed feedstock for heavy rail continuous casting:

[0055] 1. The following raw materials are used: fused magnesia (MgO content 97.3%), white corundum (Al2O3 content 99%), fine magnesium aluminum spinel powder, quicklime (CaO content 72%), and quartz sand (SiO2 content 95%), formulated according to the following weight percentages:

[0056] MgO 82%, Al2O3 3.5%, MgO-Al2O3 (magnesium aluminum spinel) 5%, CaO 2%, SiO2 2.5%, balance unavoidable impurities;

[0057] The particle size distribution of the ingredients, by weight percentage, includes:

[0058] Particles ranging from 5 to 3 mm, and not exceeding 3 mm, comprise 16%;

[0059] Particles ranging from 3 to 1 mm, and not exceeding 1 mm (22%);

[0060] Particles ≤1mm accounted for 62%;

[0061] Of the particles ≤1mm, the content of particles ≤0.05mm is 34% by weight.

[0062] 2. Sinter the ingredients from step 1 to obtain dry material for heavy rail continuous casting in the tundish;

[0063] The sintering process is as follows: the temperature is increased to 600℃ at 10℃ / min, then increased to 800℃ at 3℃ / min, held for 2 h, then increased to 1200℃ at 5℃ / min, and finally increased to 1400℃ at 3℃ / min, held for 47 min.

[0064] 3. The aforementioned dry-type material for heavy rail continuous casting is applied in the continuous casting process of heavy rail steel; wherein, the elemental composition of the molten steel, by weight percentage, is as follows:

[0065] C 0.75%~0.82%, Si 0.10%~0.40%, Mn 0.90%~1.20%, P≤0.025%, S≤0.025%, Cr0.40%~0.50%, V 0.04%~0.06%, balance Fe and unavoidable impurities.

[0066] After 810 min of smelting, chemical analysis was performed on the slag covering agent in the tundish casting zone of the above-mentioned castings. The results showed that the MgO content in the slag originating from the dry erosion of refractory materials was significantly reduced, with the highest mass content of MgO in the slag decreasing from a maximum of 29.8% to 13.8%. The average erosion rate decreased from 1.5 mm / furnace to an average of 1.05 mm / furnace.

[0067] Example 2

[0068] Preparation of dry-mixed feedstock for heavy rail continuous casting:

[0069] 1. The following raw materials are used: fused magnesia (MgO content 97.3%), white corundum (Al2O3 content 99%), fine magnesium aluminum spinel powder, quicklime (CaO content 72%), and quartz sand (SiO2 content 95%), formulated according to the following weight percentages:

[0070] MgO 82.5%, Al2O3 3%, MgO-Al2O3 (magnesium aluminum spinel) 6.5%, CaO 1.5%, SiO2 2.3%, balance unavoidable impurities;

[0071] The particle size distribution of the ingredients, by weight percentage, includes:

[0072] Particles ranging from 5 to 3 mm, and not exceeding 12% of those not exceeding 3 mm;

[0073] Particles ranging from 3 to 1 mm, and not exceeding 1 mm (21%);

[0074] Particles ≤1mm accounted for 67%;

[0075] Of the particles ≤1mm, the content of particles ≤0.05mm is 37% by weight.

[0076] 2. Sinter the ingredients from step 1 to obtain dry material for heavy rail continuous casting in the tundish;

[0077] The sintering process is as follows: the temperature is increased to 600℃ at 10℃ / min, then increased to 800℃ at 3℃ / min, held for 2 h, then increased to 1200℃ at 5℃ / min, and finally increased to 1400℃ at 3℃ / min, held for 47 min.

[0078] 3. The aforementioned dry-type material for heavy rail continuous casting is applied in the continuous casting process of heavy rail steel; wherein, the elemental composition of the molten steel, by weight percentage, is as follows:

[0079] C 0.95%~1.00%, Si 0.67%~0.70%, Mn 0.85%~0.90%, P≤0.015%, S≤0.010%, Cr0.35%~0.40%, V 0.07%~0.08%, balance Fe and unavoidable impurities.

[0080] After 805 min of smelting, chemical analysis was performed on the slag covering agent in the tundish casting zone of the above-mentioned castings. The results showed that the MgO content in the slag originating from the dry erosion of refractory materials was significantly reduced, with the highest mass content of MgO in the slag decreasing from a maximum of 26.9% to 12.8%. The average erosion rate decreased from 1.7 mm / heat to an average of 1.04 mm / heat.

[0081] Example 3

[0082] Preparation of dry-mixed feedstock for heavy rail continuous casting:

[0083] 1. The following raw materials are used: fused magnesia (MgO content 97.3%), white corundum (Al2O3 content 99%), fine magnesium aluminum spinel powder, quicklime (CaO content 72%), and quartz sand (SiO2 content 95%), formulated according to the following weight percentages:

[0084] MgO 83%, Al2O3 2.5%, MgO-Al2O3 (magnesium aluminum spinel) 8%, CaO 1.0%, SiO2 2.0%, balance unavoidable impurities;

[0085] The particle size distribution of the ingredients, by weight percentage, includes:

[0086] Particles ranging from 5 to 3 mm, and not exceeding 10% of those exceeding 3 mm;

[0087] Particles ranging from 3 to 1 mm, and not exceeding 20% ​​of those exceeding 1 mm;

[0088] 70% of the particles are ≤1mm;

[0089] Of the particles ≤1mm, the content of particles ≤0.05mm is 39% by weight.

[0090] 2. Sinter the ingredients from step 1 to obtain dry material for heavy rail continuous casting in the tundish;

[0091] The sintering process is as follows: the temperature is increased to 600℃ at 10℃ / min, then increased to 800℃ at 3℃ / min, held for 2 h, then increased to 1200℃ at 5℃ / min, and finally increased to 1400℃ at 3℃ / min, held for 45 min.

[0092] 3. The aforementioned dry-type material for heavy rail continuous casting is applied in the continuous casting process of heavy rail steel; wherein, the elemental composition of the molten steel, by weight percentage, is as follows:

[0093] C 0.90%~0.96%, Si 0.64%~0.68%, Mn 0.75%~0.85%, P≤0.012%, S≤0.009%, Cr0.30%~0.35%, V 0.06%~0.08%, balance Fe and unavoidable impurities.

[0094] After 813 min of smelting, chemical analysis was performed on the slag covering agent in the tundish casting zone of the above-mentioned castings. The results showed that the MgO content in the slag originating from the dry erosion of refractory materials was significantly reduced, with the highest mass content of MgO in the slag decreasing from a maximum of 28.1% to 11.3%. The average erosion rate decreased from 1.46 mm / heat to an average of 0.89 mm / heat.

[0095] Comparative Example 1

[0096] 1. The following formula, based on the following weight percentages, uses fused magnesia (MgO content 97.3%), white corundum (Al2O3 content 99%), quicklime (CaO content 72%), and quartz sand (SiO2 content 95%) as raw materials:

[0097] MgO 87%, Al2O3 4%, CaO 3%, SiO2 3.5%, balance unavoidable impurities;

[0098] The particle size distribution of the ingredients, by weight percentage, includes:

[0099] Particles ranging from 5 to 3 mm, and not exceeding 15% of those exceeding 3 mm;

[0100] Particles ranging from 3 to 1 mm, and not exceeding 1 mm (13%);

[0101] 72% of the particles were ≤1mm;

[0102] 2. Sinter the ingredients from step 1 to obtain dry material for heavy rail continuous casting in the tundish;

[0103] The sintering process is as follows: the temperature is increased to 700℃ at 12℃ / min, then increased to 1000℃ at 3℃ / min, held for 1 h, then increased to 1200℃ at 8℃ / min, and finally increased to 1400℃ at 2℃ / min, held for 20 min.

[0104] 3. The aforementioned dry-type material for heavy rail continuous casting is applied in the continuous casting process of heavy rail steel; wherein, the elemental composition of the molten steel, by weight percentage, is as follows:

[0105] C 0.77%~0.81%, Si 0.12%~0.40%, Mn 0.90%~1.15%, P≤0.025%, S≤0.025%, Cr0.45%, V 0.05%, balance Fe and unavoidable impurities.

[0106] After 810 min of smelting, chemical analysis was performed on the slag covering agent in the tundish casting zone of the above-mentioned castings. The results showed that the MgO content in the slag originating from the erosion of the refractory dry charge increased rapidly, with the highest MgO content in the slag reaching 27.6%. The average erosion rate was 1.9 mm / furnace.

[0107] As demonstrated in the examples and comparative examples, this invention successfully improved the resistance to penetration erosion of the dry refractory material in the tundish during continuous casting of heavy rail steel. By adding MgO-Al2O3 (magnesium aluminum spinel) fine powder and optimizing the particle size distribution, the porosity of the refractory material was reduced, the penetration depth of the covering agent slag was decreased, and the reaction between Al2O3 in the covering agent slag and SiO2 and CaO in the dry refractory material was slowed down to form a low-melting-point phase. The addition of MgO-Al2O3 fine powder improved high-temperature thermal stability and weakened the volume expansion cracking and peeling corrosion caused by MgO-Al2O3 formation. Simultaneously, the slag reacted with the MgO-Al2O3 phase after penetration to form a high-viscosity phase, significantly reducing the penetration internal cracking of the slag. Ultimately, the quality of the dry refractory material in the tundish during continuous casting of heavy rail steel was successfully improved, with the average erosion rate decreasing from 1.7 mm / heat to an average of 0.89 mm / heat; the increase in MgO in the covering agent slag was significantly reduced, and the highest MgO content in the slag decreased from a maximum of 29.8% to 11.3%. This lays an important foundation for high-cleanliness continuous casting and low refractory consumption, effectively supporting green, low-consumption, and high-quality production.

[0108] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing dry-mixed feedstock for heavy rail continuous casting, comprising the following steps: A. Ingredients as per the following weight percentages: MgO 82%~83%, Al2O3 2.5%~3.5%, MgO-Al2O3 5%~8%, CaO 1.0%~2.0%, SiO2 2.0%~2.5%, balance unavoidable impurities; B. Sinter the ingredients from step A to obtain dry material for heavy rail continuous casting.

2. The preparation method according to claim 1, characterized in that, The particle size distribution of the ingredients includes 5~3 mm, 3~1 mm and ≤1 mm.

3. The preparation method according to claim 1, characterized in that, The particle size distribution of the ingredients, by weight percentage, includes: Particles of 5-3 mm, and not exceeding 3 mm, comprise 10%-16%; Particles ranging from 3 to 1 mm, and not exceeding 1 mm, account for 20% to 22%; Particles ≤1mm account for 62%~70%; The sum of the amounts of the components is 100%.

4. The preparation method according to claim 1, characterized in that, Among particles ≤1mm, the content of particles ≤0.05mm is 34%~39% by weight.

5. The preparation method according to claim 1, characterized in that, The sintering process is as follows: the temperature is increased to 550-650℃ at a rate of 9-11℃ / min, then increased to 750-850℃ at a rate of 2-4℃ / min, and held for 1-3 hours. Then the temperature is increased to 1150-1250℃ at a rate of 4-6℃ / min, and finally increased to 1350-1450℃ at a rate of 2-4℃ / min, and held for 45-50 minutes.

6. The preparation method according to claim 1, characterized in that, In step A, the ingredients include at least one of magnesia, corundum, magnesium aluminum spinel, quicklime, and silica powder.

7. Dry ladle material for heavy rail continuous casting prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the dry-type material for heavy rail continuous casting as described in claim 7 in the heavy rail continuous casting process.

9. The application according to claim 8, characterized in that, The elemental composition of the molten steel in the continuous casting process of heavy rail steel, by weight percentage, is as follows: C 0.75%~0.82%, Si 0.10%~0.40%, Mn 0.90%~1.20%, P≤0.025%, S≤0.025%, Cr 0.40%~0.50%, V 0.04%~0.06%, with the balance being Fe and unavoidable impurities.