Casting powder special for bucket tooth steel and application of casting powder

Abstract

The invention relates to the technical field of steel and iron smelting, in particular to casting powder special for bucket tooth steel and application of the casting powder, and the casting powder contains CaO, SiO2, Al2O3, MgO, R2O and C; wherein the mass fraction of the CaO is 25%; the mass fraction of the SiO2 is 29%; the mass fraction of Al2O3 is 3%; the mass fraction of MgO is 1%; the mass fraction of the R2O is 9%; the R2O is Na2O and / or K2O. The viscosity, the thermal resistance and the melting point of the casting powder are improved, and the melting speed is reduced, so that the heat transfer effect in the continuous casting process is optimized, and the surface quality of a casting blank is improved. Specifically, the melting speed of the casting powder is adjusted to 38 s, and compared with original casting powder, the melting speed of the casting powder is obviously increased; according to the method, the components of the casting powder are accurately controlled, so that optimization of the thermal resistance and the viscosity of the casting powder is ensured, the weak cooling effect of a casting blank is achieved, the casting powder can better meet the continuous casting requirement of the bucket tooth steel, and powerful technical support is provided for large-scale and high-quality production of the bucket tooth steel.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, and in particular to protective slag dedicated to bucket tooth steel and application thereof. Background Art

[0002] Bucket teeth are important parts of construction machinery such as excavators and loaders, and are also vulnerable parts. They are composed of a tooth seat and a tooth tip, which are connected by a pin. During operation, the tooth tip of the bucket tooth is the main failure part, so you only need to replace the tooth tip when replacing it.

[0003] Imported construction machinery brands mainly include Carter, Komatsu, Hitachi, etc. Domestic construction machinery brands mainly include Xugong, Sany, Lingong, Liugong, etc. According to the production method, it can be divided into two categories: cast bucket teeth and forged bucket teeth. Among them, the cost of cast bucket teeth is relatively low, the process is mature, and it currently occupies the mainstream of the market. The cost of forged bucket teeth is relatively high, but the quality of bucket teeth is relatively better. Some main engine manufacturers are gradually tending to use forged bucket teeth. The failure forms of bucket teeth are mainly: 1. Wear. During the working process, the bucket teeth repeatedly interact with hard stones, concrete, etc., and different working parts of the bucket teeth will produce different degrees of wear, which is also the main form of bucket teeth failure. 2. Deformation. During the working process, when the bucket teeth first contact the material, due to the fast speed, the tooth tip of the bucket teeth is strongly impacted. If the yield strength of the bucket teeth is low, the tooth tip of the bucket teeth will undergo plastic deformation. 3. Fracture. Excavators have various working methods. In addition to longitudinal impact and wear, the force state of the bucket teeth will also be impacted and resisted in the lateral direction. If the force is too large, it will break.

[0004] Bucket tooth steel has poor thermal conductivity due to its high silicon steel characteristics. It is prone to defects such as steel leakage and casting dents during continuous casting, which seriously affects production efficiency and product quality. The mold slag in the existing technology often cannot meet the special requirements of bucket tooth steel continuous casting, resulting in poor surface quality of the casting. Therefore, it is particularly important to develop a special mold slag suitable for bucket tooth steel. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the protective slag in the prior art often fails to meet the special requirements of bucket tooth steel continuous casting, resulting in poor surface quality of the ingot, thereby providing a protective slag dedicated to bucket tooth steel and its application.

[0006] In order to achieve the above-mentioned object, in the first aspect, the present invention provides a protective slag specially used for bucket tooth steel, wherein the protective slag contains CaO, SiO2, Al2O3, MgO, R2O and C; wherein:

[0007] The mass fraction of CaO is 25%;

[0008] The mass fraction of SiO2 is 29%;

[0009] The mass fraction of Al2O3 is 3%;

[0010] The mass fraction of MgO is 1%;

[0011] The mass fraction of R2O is 9%;

[0012] The R2O is Na2O and / or K2O.

[0013] Preferably, the binary basicity of the protective slag is 0.82, wherein the binary basicity R2 = ω(CaO) / ω(SiO2).

[0014] Preferably, the melting temperature of the mold slag is 1050-1100°C.

[0015] Preferably, at a temperature of 1300° C., the viscosity of the protective slag is 0.3 Pa·s.

[0016] Preferably, the melting rate of the protective slag is 38s.

[0017] In a second aspect, the present invention provides a use of the protective slag described in the first aspect in the production of bucket tooth steel.

[0018] According to the above technical scheme, the present invention improves the viscosity, thermal resistance and melting point of the protective slag, reduces the melting rate, thereby optimizing the heat transfer effect during the continuous casting process and improving the surface quality of the ingot. Specifically, the present invention adjusts the melting rate of the protective slag to 38s, which is significantly higher than the original protective slag; the precise control of the protective slag composition ensures the optimization of its thermal resistance and viscosity, thereby achieving the "weak cooling" effect of the ingot, so that the protective slag can better meet the continuous casting requirements of bucket tooth steel, and provide strong technical support for the large-scale and high-quality production of bucket tooth steel.

[0019] The protective slag of the present invention is used in the continuous casting process of bucket tooth steel, and forms a uniform and stable liquid slag film in the continuous casting process to ensure the surface quality of the ingot, which can effectively prevent the ingot from sinking and steel leakage, meet the special needs of the continuous casting of bucket tooth steel, significantly improve the yield and quality of bucket tooth steel, and reduce production costs.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0021] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] In a first aspect, the present invention provides a protective slag specially used for bucket tooth steel, wherein the protective slag contains CaO, SiO2, Al2O3, MgO, R2O and C; wherein:

[0023] The mass fraction of CaO is 25%;

[0024] The mass fraction of SiO2 is 29%;

[0025] The mass fraction of Al2O3 is 3%;

[0026] The mass fraction of MgO is 1%;

[0027] The mass fraction of R2O is 9%

[0028] The R2O is Na2O and / or K2O.

[0029] The present invention improves the viscosity, thermal resistance and melting point of the protective slag, reduces the melting rate, thereby optimizing the heat transfer effect during the continuous casting process and improving the surface quality of the ingot. Specifically, the present invention adjusts the melting rate of the protective slag to 38s, which is significantly higher than the original protective slag; the precise control of the protective slag composition ensures the optimization of its thermal resistance and viscosity, thereby achieving the "weak cooling" effect of the ingot, so that the protective slag can better meet the continuous casting requirements of bucket tooth steel, and provide strong technical support for the large-scale and high-quality production of bucket tooth steel.

[0030] In a preferred embodiment of the present invention, the binary basicity of the protective slag is 0.82, wherein the binary basicity R2=ω(CaO) / ω(SiO2).

[0031] In a preferred embodiment of the present invention, the melting temperature of the mold slag is 1050-1100°C.

[0032] In a preferred embodiment of the present invention, at a temperature of 1300° C., the viscosity of the mold slag is 0.3 Pa·s.

[0033] In a preferred embodiment of the present invention, the melting rate of the mold slag is 38s.

[0034] In a second aspect, the present invention provides a use of the protective slag described in the first aspect in the production of bucket tooth steel.

[0035] The protective slag of the present invention is used in the continuous casting process of bucket tooth steel, and forms a uniform and stable liquid slag film in the continuous casting process to ensure the surface quality of the ingot, which can effectively prevent the ingot from sinking and steel leakage, meet the special needs of the continuous casting of bucket tooth steel, significantly improve the yield and quality of bucket tooth steel, and reduce production costs.

[0036] Through the implementation of the above technical scheme, using the protective slag of the present invention to produce bucket tooth steel can significantly improve the surface quality of bucket tooth steel continuous casting billets, reduce the phenomenon of billet depression and steel leakage; at the same time, optimize the heat transfer effect, achieve uniform cooling of the billet, improve the yield rate and product quality; further, reduce production costs, improve production efficiency, and enhance the market competitiveness of products.

[0037] The present invention is described in detail below with reference to the embodiments.

[0038] Table 1 shows the mass fractions of the components in the protective slag dedicated to the bucket tooth steel of Example 1 of the present invention and the protective slag of Comparative Example 1.

[0039] CaO / % <![CDATA[SiO2 / %]]> <![CDATA[Al2O3 / %]]> MgO / % <![CDATA[R2O / %]]> Example 1 25 29 3 1 9 Comparative Example 1 25 31 5 1 9

[0040] Table 2 shows the performance and process parameters of the protective slag dedicated to the bucket tooth steel of Example 1 of the present invention and the protective slag of Comparative Example 1

[0041] <![CDATA[Binary basicity (R2 = CaO / SiO2)]]> Melting temperature / ℃ Viscosity of mold slag at 1300℃ / Pa·s Example 1 0.82 1050-1100 0.3 Comparative Example 1 0.87 1100-1150 0.5

[0042] From the data in Table 1 and Table 2, it can be seen that the protective slag formula dedicated to bucket tooth steel of the present invention is different from that of the prior art (Comparative Example 1) The formula and performance of the protective slag are different.

[0043] The present invention adjusts the formula of protective slag dedicated to bucket tooth steel to make the cracking ratio of bucket tooth steel continuous casting billet change from 15.6% to below 1%, and the leakage rate is reduced from 5.5% to 0, indicating that the protective slag dedicated to bucket tooth steel of the present invention The yield and quality of bucket tooth steel are significantly improved, and production costs are reduced.

[0044] In summary, the special protective slag for bucket tooth steel provided by the present invention effectively solves the ingot quality problem existing in the continuous casting process of bucket tooth steel by accurately controlling the components and performance indicators of the protective slag, and has important practical application value.

[0045] In addition to the above-mentioned key technical points which must be implemented as required, the present invention requires that other production processes be implemented in a conventional manner.

[0046] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0048] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A protective slag specially used for bucket tooth steel, characterized in that: The protective slag contains CaO, SiO2, Al2O3, MgO, R2O and C; wherein, The mass fraction of CaO is 25%; The mass fraction of SiO2 is 29%; The mass fraction of Al2O3 is 3%; The mass fraction of MgO is 1%; The mass fraction of R2O is 9%; The R2O is Na2O and / or K2O.

2. The protective slag according to claim 1, characterized in that: The binary basicity of the protective slag is 0.82, wherein the binary basicity R2=ω(CaO) / ω(SiO2).

3. The protective slag according to claim 1 or 2, characterized in that: The melting temperature of the protective slag is 1050-1100°C.

4. The mold slag according to any one of claims 1 to 3, characterized in that: Under the condition of a temperature of 1300° C., the viscosity of the protective slag is 0.3 Pa·s.

5. The mold slag according to any one of claims 1 to 4, characterized in that: The melting speed of the protective slag is 38s.

6. Use of the protective slag as described in any one of claims 1 to 5 in the production of bucket tooth steel.