Bucket tooth tip material and preparation method thereof

Abstract

The invention discloses a bucket tooth tip material and a preparation method thereof. Comprising the following components in percentage by weight: 0.20%-0.35% of carbon, 0.60%-1.50% of silicon, 0.70%-1.50% of manganese, 0.80%-1.10% of chromium, 0.01%-0.04% of aluminum, less than 0.015% of phosphorus, less than 0.015% of sulfur, 0.001%-0.006% of boron, 0.03%-0.18% of yttrium or 0.01%-0.03% of strontium, and the balance of iron and impurities. The preparation method comprises a batching process, a melting and component adjusting process, a charging process, a casting process and a heat treatment process. The bucket tooth tip material disclosed by the invention has good mechanical properties and wear resistance, relatively low tooth breakage rate and wide application range at low temperature, the production cost is further reduced, and the preparation method is wide in application range and has good application potential.

Description

Technical Field

[0001] The present application relates to the field of alloy technology, and in particular to a bucket tooth tip material and a preparation method thereof. Background Art

[0002] Large bucket teeth usually adopt a combined design, consisting of a tooth tip and a tooth seat, and the tooth tip is connected to the tooth seat through a pin. Since the tooth tip is the part that directly contacts the material, it needs to have good wear resistance and the ability to not break under impact loads. Usually, the wall thickness of the tooth tip of a large bucket tooth can exceed 100 mm, which requires the material to have a high hardenability, otherwise it is difficult to achieve the ideal comprehensive performance.

[0003] At present, the main material of bucket tooth tip is high-strength quenched and tempered structural steel, namely ZG30CrMnSi alloy structural wear-resistant steel. Although this material has good casting performance, it is not hardenable enough, resulting in a large difference in hardness between the surface and the core of the bucket tooth tip material, which in turn leads to poor wear resistance. In addition, this material has poor low-temperature toughness and is prone to breakage when used in cold environments. Therefore, the research direction of this industry is to improve the hardenability and comprehensive performance of bucket tooth tip materials. However, the existing bucket tooth tip materials still have a tooth breakage rate of 3% to 5% when used in low-temperature environments. Therefore, bucket tooth tip materials and preparation methods need to be improved urgently to adapt to a wide range of application environments. Summary of the invention

[0004] One purpose of the present application is to provide a bucket tooth tip material and a preparation method thereof, which is beneficial to enhancing the mechanical properties of the bucket tooth tip material, improving the wear resistance of the tooth tip, thereby reducing the tooth breakage rate during use and further enhancing market competitiveness.

[0005] Another object of the present application is to provide a bucket tooth tip material and a preparation method thereof, which is conducive to reducing the production cost during preparation and further optimizing the production efficiency.

[0006] To achieve the above purpose, the technical solution adopted in the present application is to provide a bucket tooth tip material, including the following components in weight percentage: a carbon content of 0.20% to 0.35%, a silicon content of 0.60% to 1.50%, a manganese content of 0.70% to 1.50%, a chromium content of 0.80% to 1.10%, an aluminum content of 0.01% to 0.04%, a phosphorus content of less than 0.015%, a sulfur content of less than 0.015%, a boron content of 0.001% to 0.006%, a yttrium content of 0.03% to 0.18% or a strontium content of 0.01% to 0.03%, and the remainder is iron and impurities.

[0007] In one embodiment, the carbon content is 0.27% to 0.34%, the silicon content is 0.90% to 1.20%, the manganese content is 0.80% to 1.10%, the yttrium content is 0.05% to 0.15%, the strontium content is 0.01% to 0.02%, and the boron content is 0.001% to 0.005%.

[0008] According to another aspect of the present application, a method for preparing a bucket tooth tip material is also provided, comprising the steps of:

[0009] S100, adding a carburizer into a forging furnace, adding high-strength quenched and tempered alloy structural steel for melting, and obtaining a first molten liquid;

[0010] S200, taking the first molten liquid for component analysis, and adjusting the composition of the first molten liquid to have a carbon content of 0.27% to 0.34%, a silicon content of 0.90% to 1.20%, a manganese content of 0.80% to 1.10%, a chromium content of 0.80% to 1.10%, a phosphorus content of less than 0.015%, and a sulfur content of less than 0.015%, to obtain a second molten liquid;

[0011] S300, adding the second molten liquid to the aluminum-yttrium alloy or the aluminum-strontium alloy and the ferroboron alloy, and stirring the mixture to obtain a third molten liquid;

[0012] S400, obtaining a bucket tooth tip material by casting and heat treating the third molten liquid.

[0013] In one embodiment, the step S400 further includes the steps of:

[0014] S410, pouring the third molten liquid into the mold cavity to cast into a first tooth tip;

[0015] S420, cooling the first tooth tip to a first temperature, then performing mold opening treatment, and maintaining the temperature at a second temperature for 0.5 h to 1.5 h, and cooling the first tooth tip to room temperature in air to obtain a second tooth tip;

[0016] S430, heating the second tooth tip to a third temperature, then keeping the temperature for 10 to 20 minutes, and cooling the second tooth tip to 200° C. in a quenching liquid to obtain a third tooth tip;

[0017] S440, keeping the third tooth tip at the fourth temperature for 4 hours to 12 hours, and then cooling it to room temperature in air to obtain a bucket tooth tip material.

[0018] In one embodiment, the yttrium content of the aluminum-yttrium alloy is 5% to 10%, the strontium content of the aluminum-strontium alloy is 5% to 10%, and the boron content of the ferroboron alloy is 20% to 25%.

[0019] In one embodiment, the temperature of the second molten liquid in step S300 is 1650°C to 1750°C.

[0020] In one embodiment, in step S420, the first temperature is 300°C to 400°C, the second temperature is 900°C to 950°C, the third temperature is 850°C to 950°C, and the fourth temperature is 150°C to 300°C.

[0021] In one embodiment, the carburizer is selected from one or more of carburized pig iron, electrode powder, coke powder, artificial graphite, charcoal powder and petroleum coke powder.

[0022] In one embodiment, the high-strength quenched and tempered alloy structural steel is selected from one or more of ZG30CrMnSi alloy or medium-carbon CrMnSi alloy.

[0023] In one embodiment, the mass percentage of the carburizer added is 0.10% to 0.15% of the mass of the forging raw material. DETAILED DESCRIPTION

[0024] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0025] As used herein, the term "prepared from" is synonymous with "comprising". As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such composition, step, method, article, or apparatus.

[0026] When an amount, concentration or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing the range used formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range includes its end values ​​and all integers and fractions within the range.

[0027] Approximate terms in the specification and claims are used to modify quantities, indicating that the present invention is not limited to the specific quantity, but also includes acceptable and modified parts close to the quantity without causing changes in the relevant basic functions. Accordingly, the use of "about", "approximately", etc. to modify a numerical value means that the present invention is not limited to the exact numerical value. In some examples, the approximate terms may correspond to the accuracy of the instrument for measuring the numerical value. In the specification and claims of this application, range limitations can be combined and / or interchanged, and if not otherwise stated, these ranges include all subranges contained therein.

[0028] According to one aspect of the present invention, a bucket tooth tip material includes the following components in weight percentage: a carbon content of 0.20% to 0.35%, a silicon content of 0.60% to 1.50%, a manganese content of 0.70% to 1.50%, a chromium content of 0.80% to 1.10%, an aluminum content of 0.01% to 0.04%, a phosphorus content of less than 0.015%, a sulfur content of less than 0.015%, a boron content of 0.001% to 0.006%, a yttrium content of 0.03% to 0.18% or a strontium content of 0.01% to 0.03%, and the remainder is iron and impurities.

[0029] The present application optimizes the content of each chemical component in the bucket tooth tip material to obtain a bucket tooth tip material with superior mechanical properties, which can be widely used in various use environments. Among them, the hardenability of the bucket tooth tip material is further optimized by adding boron elements, the mechanical properties and wear resistance of the final product are enhanced, and the performance is further improved. On the other hand, by adding yttrium or strontium elements, the grain size of the alloy is refined, thereby improving the mechanical properties and corrosion resistance of the bucket tooth tip material. The yttrium element can also stabilize the dislocation substructure and strengthen the grain boundary, thereby significantly extending the creep life of the bucket tooth tip material and further improving the application performance of the bucket tooth tip material; strontium elements can also refine the structure, further improve the impact toughness, and enhance the performance of the bucket tooth tip material. On the other hand, the bucket tooth tip material provided by the present application does not use relatively expensive metal elements such as nickel and molybdenum during preparation, thereby reducing production costs and optimizing the production process.

[0030] In one embodiment, the carbon content is 0.27% to 0.34%, specifically, the carbon content is 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%. The silicon content is 0.90% to 1.20%, specifically, the silicon content is 0.90%, 0.95%, 1.00%, 1.05%, 1.10%, 1.15%, 1.20%. The manganese content is 0.80% to 1.10%, specifically, the manganese content is 0.80%, 0.85%, 0.90%, 0.95%, 1.00%, 1.05%, 1.10%. The chromium content is 0.80% to 1.10%, specifically, the chromium content is 0.80%, 0.85%, 0.90%, 0.95%, 1.00%, 1.05%, 1.10%. The phosphorus content is less than 0.015%, and the sulfur content is less than 0.015%. The reasonable proportion and control of these elements are crucial to the performance of the bucket tooth tip material. For example, by adding carbon, silicon, chromium and manganese, the wear resistance and toughness of the bucket tooth tip material can be improved, thereby extending the service life of the bucket tooth material. At the same time, controlling the content of phosphorus and sulfur can avoid the material brittleness problem caused by impurities and ensure the reliability of the bucket tooth material under harsh working conditions.

[0031] In one embodiment, the yttrium content is 0.05% to 0.15%, specifically, the yttrium content is 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%. Appropriate yttrium content is beneficial to improving the strength and hardness of bucket tooth materials, thereby increasing the service life of bucket tooth materials.

[0032] In one embodiment, the strontium content is 0.01% to 0.02%, specifically, the strontium content is 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%. Appropriate strontium content is beneficial to improving the strength and hardness of bucket tooth materials, thereby increasing the service life of bucket tooth materials.

[0033] In one embodiment, the boron content is 0.001% to 0.005%, specifically, the boron content is 0.001%, 0.002%, 0.003%, 0.004%, and 0.005%. The appropriate boron content is beneficial to improving the hardenability of the bucket tooth material and further improving the performance of the bucket tooth material.

[0034] According to another aspect of the present invention, a method for preparing a bucket tooth tip material comprises the steps of:

[0035] S100, adding a carburizer into a forging furnace, adding high-strength quenched and tempered alloy structural steel for melting, and obtaining a first molten liquid;

[0036] S200, taking the first molten liquid for component analysis, and adjusting the composition of the first molten liquid to have a carbon content of 0.27% to 0.34%, a silicon content of 0.90% to 1.20%, a manganese content of 0.80% to 1.10%, a chromium content of 0.80% to 1.10%, a phosphorus content of less than 0.015%, and a sulfur content of less than 0.015%, to obtain a second molten liquid;

[0037] S300, adding the second molten liquid to the aluminum-yttrium alloy or the aluminum-strontium alloy and the ferroboron alloy, and stirring the mixture to obtain a third molten liquid;

[0038] S400, obtaining a bucket tooth tip material by casting and heat treating the third molten liquid.

[0039] The preparation method provided in this application is conducive to improving the mechanical properties and performance of bucket tooth tip materials, has good application prospects, and is suitable for a wide range of application scenarios. In other words, during the preparation process, a balance is achieved between the mechanical strength and toughness of bucket tooth tip materials, thereby reducing the tooth breakage rate of bucket tooth materials during use and further improving their performance.

[0040] In one embodiment, the step S400 further includes the steps of:

[0041] S410, pouring the third molten liquid into the mold cavity to cast into a first tooth tip;

[0042] S420, cooling the first tooth tip to a first temperature, then performing mold opening treatment, and maintaining the temperature at a second temperature for 0.5 h to 1.5 h, and cooling the first tooth tip to room temperature in air to obtain a second tooth tip;

[0043] S430, heating the second tooth tip to a third temperature, then keeping the temperature for 10 to 20 minutes, and cooling the second tooth tip to 200° C. in a quenching liquid to obtain a third tooth tip;

[0044] S440, keeping the third tooth tip at the fourth temperature for 4 hours to 12 hours, and then cooling it to room temperature in air to obtain a bucket tooth tip material.

[0045] Among them, through the homogenization process in step S420 of the preparation method, the stress and structural inhomogeneity inside the forging can be effectively eliminated, and the internal grains of the bucket tooth tip material can be further refined, which is helpful to improve the overall performance of the bucket tooth tip material, reduce the risk of cracks and deformation caused in the subsequent preparation and processing, and thus extend the service life of the bucket tooth material and enhance market competitiveness. On the one hand, through the quenching process in step S430, the hardness and mechanical properties of the bucket tooth tip material can be significantly improved, while improving certain toughness and wear resistance. It can be understood that the quenching process can also optimize the stress distribution phenomenon inside the bucket tooth tip material, thereby improving its fatigue resistance and fracture resistance, and enhancing the performance. On the other hand, introducing the low-temperature tempering process in step S440 after the quenching treatment is conducive to eliminating the stress generated in the bucket tooth tip material during the quenching process, further preventing the occurrence of grinding and cracking, and improving the mechanical properties of the bucket tooth tip material. Furthermore, low-temperature tempering treatment is beneficial to improving the microstructure of the material and forming an oxide layer, thereby enhancing the corrosion resistance of the bucket tooth tip material and reducing the surface roughness, thereby improving the comprehensive performance of the material.

[0046] In one embodiment, the yttrium content in the aluminum-yttrium alloy is 5% to 10%, specifically, the yttrium content in the aluminum-yttrium alloy is 5%, 6%, 7%, 8%, 9% and 10%. It can be understood that yttrium is an effective grain refiner that can significantly refine the grain size of the aluminum alloy, thereby improving the strength and hardness of the material, thereby enhancing the wear resistance and mechanical properties of the bucket tooth tip material, and reducing the tooth breakage rate during use. In other words, the aluminum-yttrium alloy combines the lightweight properties of aluminum and the strengthening effect of yttrium, so that it has higher mechanical strength and wear resistance while maintaining a lower density.

[0047] In one embodiment, the strontium content in the aluminum-strontium alloy is 5% to 10%, specifically, the strontium content in the aluminum-strontium alloy is 5%, 6%, 7%, 8%, 9% and 10%. It can be understood that the addition of strontium can also play a role in refining the grain size, thereby enhancing the wear resistance and mechanical strength of the bucket tooth tip material, and the good toughness of the aluminum-strontium alloy is conducive to the design and manufacture of bucket tooth materials. Therefore, by adding aluminum-yttrium alloy or aluminum-strontium alloy, the comprehensive performance of the bucket tooth tip material can be significantly improved, including strength, hardness, corrosion resistance, thermal conductivity, toughness, plasticity and impact toughness, thereby improving the service life and work efficiency of the bucket tooth.

[0048] In one embodiment, the boron content in the ferroboron alloy is 20% to 25%, specifically, the boron content in the ferroboron alloy is 20%, 21%, 22%, 23%, 24% and 25%. By adding the boron element, the hardenability of the bucket tooth tip material is improved, and with the increase in hardenability, the bucket tooth forging has a more uniform martensitic structure during the quenching process, further improving the wear resistance, hardness and mechanical strength of the bucket tooth tip material. In other words, with the increase of quenching temperature, the hardness and tensile strength of the bucket tooth material both show an upward trend. This is because the austenitization is more sufficient at high temperature, making the distribution of alloy elements more uniform, thereby increasing the stability of supercooled austenite. In addition, the bucket tooth material with higher hardenability can obtain better impact toughness and elongation after quenching treatment, thereby obtaining a bucket tooth tip material with a lower tooth breakage rate and a longer service life.

[0049] In one embodiment, the temperature of the second molten liquid in step S300 is 1650°C to 1750°C, specifically, the temperature of the second molten liquid is 1650°C, 1660°C, 1670°C, 1680°C, 1690°C, 1700°C, 1710°C, 1720°C, 1730°C, 1740°C and 1750°C, and further preferably, the temperature of the second molten liquid is 1680°C to 1700°C. Melting at high temperature can effectively remove impurities in the material, thereby improving the purity of the material. On the one hand, high temperature melting treatment is conducive to obtaining a more uniform microstructure, thereby enhancing the overall performance of the material. On the other hand, the alloy material melted at high temperature has good hardenability, thereby producing a more uniform martensitic structure during the quenching process, further improving the wear resistance, hardness and mechanical strength of the bucket tooth tip material. On the other hand, a more uniform oxide film structure is formed on the surface of the alloy after high-temperature melting treatment, which further enhances the wear resistance and corrosion resistance of the material, making it suitable for various application environments.

[0050] In one embodiment, the first temperature in step S420 is 300° C. to 400° C., specifically, the first temperature is 300° C., 310° C., 320° C., 330° C., 340° C., 350° C., 360° C., 370° C., 380° C., 390° C., 400° C. Since the mold opening temperature has an important influence on the product quality of the bucket tooth material, when the mold opening temperature is appropriate, it not only helps to improve the strength and toughness of the bucket tooth material, but also helps to reduce the grain size and grain boundary angle of the bucket tooth material due to the faster cooling rate, which plays a role in refining the cast structure, thereby improving the strength and toughness of the material and avoiding the generation of defects.

[0051] In one embodiment, the second temperature is 900°C to 950°C, specifically, the second temperature is 900°C, 910°C, 920°C, 930°C, 940°C, and 950°C. The homogenization treatment can improve the internal structure and performance of the bucket tooth material, improve the crystal structure inside the alloy, further eliminate the casting stress, and improve the overall performance of the bucket tooth material. It is understandable that when the homogenization temperature is too high, the bucket tooth material may be overburned. Once overburning occurs, the bucket tooth material must be scrapped as a whole and then remelted, resulting in huge economic losses. Therefore, choosing a suitable homogenization temperature is crucial to avoid overburning and maintain material performance.

[0052] In one embodiment, the third temperature is 850°C to 950°C, specifically, the third temperature is 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, 930°C, 940°C, and 950°C. The quenching treatment is a process in which the material is heated to above the critical temperature and then rapidly cooled, which causes the material structure to be transformed into martensite, thereby significantly improving the hardness and wear resistance. When the quenching temperature is low, the impact toughness of the bucket tooth material is reduced due to uneven austenitization or more ferrite inside the bucket tooth material, thereby reducing the stability of the material during use. When the quenching temperature is too high, the austenite grains are coarse during heating, so that the martensite obtained after quenching is also coarse, thereby reducing the impact toughness of the bucket tooth material.

[0053] In one embodiment, the fourth temperature is 150°C to 300°C. Specifically, the fourth temperature is 150°C, 180°C, 210°C, 240°C, 270°C, and 300°C. More preferably, the fourth temperature is 160°C to 280°C. Among them, since the tempered martensite structure obtained by low-temperature tempering treatment has the advantages of hardness and good wear resistance, it has the advantages of high strength and excellent fatigue resistance when used, which is conducive to improving the service life of the bucket tooth material. Low-temperature tempering treatment can also eliminate quenching stress and improve the plasticity and toughness of the bucket tooth material. On the one hand, when the low-temperature tempering temperature is too high, the stability of the tempered martensite is reduced, which further reduces the impact toughness, strength and wear resistance of the bucket tooth material. On the other hand, too high tempering temperature may increase the tendency of heat treatment deformation and cracking of the bucket tooth material, affecting the dimensional stability and service life of the bucket tooth material. When the low-temperature tempering temperature is too low, the quenching stress inside the bucket tooth material is not completely eliminated, further reducing the performance of the bucket tooth material.

[0054] In one embodiment, the carburizer is selected from one or more of carburized pig iron, electrode powder, coke powder, artificial graphite, charcoal powder and petroleum coke powder. It is understandable that by adding the carburizer during the preparation process, the carbon content of the bucket tooth material can be increased, the organizational structure of the casting can be improved, and the grain can be refined, thereby improving the strength and hardness of the bucket tooth material. Furthermore, the addition of the carburizer can improve the distribution of carbon and alloy elements in the bucket tooth material, making the organization of the bucket tooth material denser and the composition more uniform, eliminating the segregation phenomenon generated during the casting process, improving the quality of the bucket tooth material, and thus facilitating the use performance of the bucket tooth material.

[0055] In one embodiment, the high-strength quenched and tempered alloy structural steel is selected from one or more of ZG30CrMnSi alloy or medium-carbon CrMnSi alloy. Among them, since ZG30CrMnSi alloy and medium-carbon CrMnSi alloy both have high strength, toughness and hardenability, when they are used to prepare bucket tooth materials, the mechanical strength and wear resistance of the product are improved.

[0056] In one embodiment, the mass percentage of the carburizer added is 0.10% to 0.15% of the mass of the forging raw material, specifically, the mass percentage of the carburizer added is 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15% of the mass of the forging raw material. On the one hand, when too much carburizer is added, since the saturation concentration of carbon in the molten iron is certain, when too much carburizer is added, the time required for dissolution and diffusion becomes longer, the corresponding loss increases, and the absorption rate of the carburizer is reduced, which is not conducive to the preparation process of the bucket tooth material.

[0057] Example 1

[0058] A bucket tooth tip material comprises the following components in weight percentage: 0.30% carbon, 0.80% silicon, 0.90% manganese, 1.00% chromium, 0.02% aluminum, 0.010% phosphorus, 0.010% sulfur, 0.004% boron, 0.10% yttrium, and the remainder is iron and impurities.

[0059] Example 2

[0060] The difference between Example 2 and Example 1 is that the content of yttrium is 0.08%.

[0061] Example 3

[0062] The difference between Example 3 and Example 1 is that the content of yttrium is 0.12%.

[0063] Example 4

[0064] A bucket tooth tip material comprises the following components in percentage by weight: 0.30% carbon, 0.80% silicon, 0.90% manganese, 1.00% chromium, 0.02% aluminum, 0.010% phosphorus, 0.010% sulfur, 0.004% boron, 0.015% strontium, and the remainder is iron and impurities.

[0065] Example 5

[0066] The difference between Example 5 and Example 1 is that the content of strontium is 0.01%.

[0067] Example 6

[0068] The difference between Example 6 and Example 1 is that the content of strontium is 0.03%.

[0069] Comparative Example 1

[0070] A bucket tooth tip material comprises the following components in weight percentage: 0.30% carbon, 0.80% silicon, 0.90% manganese, 1.00% chromium, 0.02% aluminum, 0.010% phosphorus, 0.010% sulfur, 0.10% yttrium, and the remainder is iron and impurities.

[0071] Comparative Example 2

[0072] A bucket tooth tip material includes the following components in weight percentage: 0.30% carbon, 0.80% silicon, 0.90% manganese, 1.00% chromium, 0.02% aluminum, 0.010% phosphorus, 0.010% sulfur, 0.015% strontium, and the remainder is iron and impurities.

[0073] Comparative Example 3

[0074] A bucket tooth tip material comprises the following components in weight percentage: 0.30% carbon, 0.80% silicon, 0.90% manganese, 1.00% chromium, 0.02% aluminum, 0.010% phosphorus, 0.010% sulfur, and the remainder iron and impurities.

[0075] Performance Evaluation

[0076] The tooth tip materials of Examples 1 to 6 and Comparative Examples 1 to 3 were subjected to hardness tests and low-temperature impact tests at -40°C, and the production costs were estimated based on the price of ZG30CrMnSi alloy. The test results are shown in Table 1. Table 1: Performance test of bucket tooth tip materials

[0077] It can be understood that, referring to Examples 1 to 3, by increasing the yttrium content, the hardness of the bucket tooth tip material increases accordingly, indicating that the hardness inside the bucket tooth material increases through the effect of yttrium element grain refinement, so the material has good wear resistance. However, its low-temperature impact toughness is poor, resulting in a high tooth breakage rate, which is not conducive to the use of bucket tooth materials. On the other hand, as the yttrium content increases, the production cost of the bucket tooth material increases due to the high price of yttrium, which is not conducive to large-scale production and use.

[0078] Referring to Examples 4 to 6, it can be seen that by increasing the strontium content, the hardness of the bucket tooth tip material is slightly improved, indicating that the effect of strontium in refining the structure is beneficial to improving the hardness of the bucket tooth material, thereby enhancing the wear resistance of the material. However, when the strontium content is further increased, the low-temperature impact toughness of the material decreases, which not only increases the production cost of the bucket tooth material, but also increases the tooth breakage rate, which is not conducive to the large-scale application of bucket tooth tip materials.

[0079] Referring to Comparative Examples 1 and 2, it can be seen that the addition of yttrium or strontium can maintain the hardness and low-temperature impact toughness of the bucket tooth tip material to a certain extent. On the other hand, since boron can effectively increase the hardenability of the bucket tooth tip material, reducing the use of boron, reducing the uniformity of the material, and further increasing the tooth breakage rate is not conducive to the widespread application of bucket tooth tip materials.

[0080] Referring to Comparative Example 3, it can be seen that the bucket tooth tip material without adding yttrium or strontium, and boron elements has poor hardness and strength, and a high tooth breakage rate. At this time, the bucket tooth tip material has poor performance and a short service life, thereby reducing the market competitiveness of the bucket tooth tip material.

[0081] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A bucket tooth tip material, characterized in that: The invention comprises the following components in weight percentage: 0.20% to 0.35% carbon, 0.60% to 1.50% silicon, 0.70% to 1.50% manganese, 0.80% to 1.10% chromium, 0.01% to 0.04% aluminum, less than 0.015% phosphorus, less than 0.015% sulfur, 0.001% to 0.006% boron, 0.03% to 0.18% yttrium or 0.01% to 0.03% strontium, and the remainder is iron and impurities.

2. The bucket tooth tip material according to claim 1, characterized in that: The carbon content is 0.27% to 0.34%, the silicon content is 0.90% to 1.20%, the manganese content is 0.80% to 1.10%, the yttrium content is 0.05% to 0.15%, the strontium content is 0.01% to 0.02%, and the boron content is 0.001% to 0.005%.

3. A method for preparing bucket tooth tip material, characterized in that: Includes steps: S100, adding a carburizer into a forging furnace, adding high-strength quenched and tempered alloy structural steel for melting, and obtaining a first molten liquid; S200, taking the first molten liquid for component analysis, and adjusting the composition of the first molten liquid to have a carbon content of 0.27% to 0.34%, a silicon content of 0.90% to 1.20%, a manganese content of 0.80% to 1.10%, a chromium content of 0.80% to 1.10%, a phosphorus content of less than 0.015%, and a sulfur content of less than 0.015%, to obtain a second molten liquid; S300, adding the second molten liquid to the aluminum-yttrium alloy or the aluminum-strontium alloy and the ferroboron alloy, and stirring the mixture to obtain a third molten liquid; S400, obtaining a bucket tooth tip material by casting and heat treating the third molten liquid.

4. The preparation method according to claim 3, characterized in that: The step S400 further includes the steps of: S410, pouring the third molten liquid into the mold cavity to cast into a first tooth tip; S420, cooling the first tooth tip to a first temperature, then performing mold opening treatment, and maintaining the temperature at a second temperature for 0.5 h to 1.5 h, and cooling the first tooth tip to room temperature in air to obtain a second tooth tip; S430, heating the second tooth tip to a third temperature, then keeping the temperature for 10 to 20 minutes, and cooling the second tooth tip to 200° C. in a quenching liquid to obtain a third tooth tip; S440, keeping the third tooth tip at the fourth temperature for 4 hours to 12 hours, and then cooling it to room temperature in air to obtain a bucket tooth tip material.

5. The preparation method according to claim 3, characterized in that: The content of yttrium in the aluminum-yttrium alloy is 5% to 10%, the content of strontium in the aluminum-strontium alloy is 5% to 10%, and the content of boron in the ferroboron alloy is 20% to 25%.

6. The preparation method according to claim 3, characterized in that: The temperature of the second molten liquid in the step S300 is 1650°C to 1750°C.

7. The preparation method according to claim 4, characterized in that: In the step S420, the first temperature is 300°C to 400°C, the second temperature is 900°C to 950°C, the third temperature is 850°C to 950°C, and the fourth temperature is 150°C to 300°C.

8. The preparation method according to claim 3, characterized in that: The carburizer is selected from one or more of carburized pig iron, electrode powder, coke powder, artificial graphite, charcoal powder and petroleum coke powder.

9. The preparation method according to claim 3, characterized in that: The high-strength quenched and tempered alloy structural steel is selected from one or more of ZG30CrMnSi alloy or medium-carbon CrMnSi alloy.

10. The preparation method according to claim 3, characterized in that: The mass percentage of the carburizer added is 0.10% to 0.15% of the mass of the forging raw material.

Images