Titanium-containing wear-resistant bucket tooth for a drag wheel bucket excavator and a method of manufacturing the same

Abstract

A kind of wear-resistant bucket tooth containing titanium for stripping wheel excavator and its manufacturing method belong to the technical field of bucket tooth manufacturing of wheel excavator.The wear-resistant bucket tooth for stripping wheel excavator includes titanium-containing low-carbon alloy steel base body and tungsten carbide (WC) overlaying layer.In the production process, water cooling + oil cooling is used for quenching, which can effectively reduce the cracking of the bucket tooth base body during quenching, and then low-temperature tempering is carried out to eliminate internal stress while ensuring high hardness of the bucket tooth;The production process has good continuity, and can avoid the hardness reduction and cost increase caused by secondary heating during overlaying.The overlaying layer and the base body of the present application are firmly combined, and have strong anti-peeling property.The bucket tooth made of the material after the above production process has excellent wear resistance and long service life under stripping working conditions of wheel excavator.

Description

Technical Field

[0001] This invention belongs to the field of bucket tooth manufacturing technology for bucket wheel excavators, and specifically relates to a titanium-containing wear-resistant bucket tooth for peeling bucket wheel excavators and its manufacturing method. Background Technology

[0002] Bucket teeth are crucial functional components for bucket wheel excavators in excavating materials, but they are also consumable and easily worn parts. The materials excavated by bucket wheel excavators during operation typically contain a large amount of sand, with a hardness reaching 70 HRC. This causes severe wear on the bucket teeth, with a typical lifespan of only about 10 days. Bucket wheel excavators are equipped with nearly 200 bucket teeth, making replacement a massive and costly task. Worn teeth also increase energy consumption and reduce efficiency. Therefore, it is necessary to improve the wear resistance of the bucket teeth by optimizing their material and manufacturing process.

[0003] Currently, high manganese steel is widely used as the material for bucket teeth in ordinary excavators. When the bucket teeth are subjected to impact, work hardening occurs, thereby improving the wear resistance of the bucket teeth. However, high manganese steel is not suitable for excavating loose materials containing sand particles, so it is not suitable as the bucket tooth material for stripper bucket excavators. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide titanium-containing wear-resistant bucket teeth for peeling bucket excavators and their manufacturing process.

[0005] The technical solution adopted in this invention is: a wear-resistant bucket tooth for a peeling bucket excavator, the key technical point of which is that it includes a titanium-containing low-carbon alloy steel substrate and a tungsten carbide (WC) weld overlay layer. The titanium-containing low-carbon alloy steel substrate includes the following percentage components: C 0.18-0.23%, Si 0.75-1%, Cr 1.5-2%, Mn 0.85-1.1%, Mo 0.3-0.5%, Ti 0.1-0.2%, Ni 0.7-1%, S ≤0.01%, P ≤0.02%, with the remainder being Fe and unavoidable impurities.

[0006] A method for manufacturing titanium-containing wear-resistant bucket teeth for a stripping bucket excavator, the key technical points of which include the following steps:

[0007] Step 1) Take raw materials according to the element content ratio of the bucket teeth and melt them in an electric furnace to obtain molten iron;

[0008] Step 2) Perform S, P and C removal to control the content of these three elements within the required range;

[0009] During step 3), the molten steel is allowed to boil well, and after tapping and before casting, the molten steel is used to calm the ladle for 5-10 minutes to remove inclusions.

[0010] Step 4) Adjust the temperature of the molten iron to 1500±50℃, pour it into shape, and open the mold to remove the part;

[0011] Step 5) Quench the bucket tooth base casting;

[0012] Step 6) Perform low-temperature tempering treatment on the bucket tooth base casting;

[0013] Step 7) Use a flux-cored wire containing WC to surface the working area of ​​the bucket teeth.

[0014] In the above scheme, in step 4), the mold is opened and the part is removed when the temperature of the bucket tooth casting drops to 600±50℃.

[0015] In the above scheme, the quenching process in step 5) is as follows: heat the bucket tooth base casting to 1100-1150℃ and keep it at that temperature for 1.4-1.6 hours, then quench it with clean water at a temperature below 28℃. The water flow rate should be greater than 0.7m / s. When the temperature of the bucket tooth base casting drops to 300-328℃, transfer the casting to an oil bath at room temperature to cool it to room temperature.

[0016] In the above scheme, the low-temperature tempering process in step 6) is as follows: the bucket tooth base casting cooled to room temperature is heated to 200-240℃ at a rate of 5℃ / min, held for 1-1.5 hours, and then air-cooled to 100-110℃.

[0017] The beneficial effects of this invention are: the wear-resistant bucket teeth for the stripping bucket excavator include a titanium-containing low-carbon alloy steel substrate and a tungsten carbide (WC) weld overlay. The quenching process using water cooling + oil cooling effectively... reduce During the quenching process, the bucket tooth matrix cracks. Subsequent low-temperature tempering eliminates internal stress while maintaining high hardness. This production process offers good continuity and avoids the hardness reduction and cost increase caused by secondary heating during welding. The weld overlay layer of this invention is firmly bonded to the matrix and exhibits strong resistance to peeling. Bucket teeth made from the material produced using the above process exhibit excellent wear resistance and a long service life under the peeling conditions of bucket wheel excavators. Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments. Example 1

[0019] This embodiment uses a titanium-containing wear-resistant bucket tooth for a stripper bucket excavator, comprising a low-carbon alloy steel matrix. The low-carbon alloy steel matrix comprises the following percentage components: C 0.18%, Si 0.85%, Cr 1.6%, Mn 0.9%, Mo 0.35%, Ti 0.12%, Ni 0.8%, S ≤0.01%, P ≤0.02%, with the remainder being Fe and unavoidable impurities. The manufacturing process of the titanium-containing wear-resistant bucket tooth in this embodiment includes the following steps:

[0020] 1) Raw materials are prepared according to the element content ratio of the bucket teeth and melted in an electric furnace to obtain molten iron;

[0021] 2) Perform S, P, and C removal to control the content of these three elements within the required range;

[0022] 3) During this period, the molten steel is allowed to boil well. After tapping and before casting, the molten steel is used to calm the ladle for 7 minutes to remove inclusions.

[0023] 4) Adjust the temperature of the molten iron to 1480℃, pour and mold it, and open the mold and remove the part when the temperature of the bucket tooth casting drops to 570℃;

[0024] 5) Heat the bucket tooth base casting to 1110℃ and hold for 1.5 hours, then quench it with clean water at a temperature below 28℃. The water flow rate should be greater than 0.7m / s. When the temperature of the bucket tooth base casting drops to 320℃, transfer the casting to an oil bath at room temperature to cool to room temperature.

[0025] 6) Heat the bucket tooth base casting to 200°C at a rate of 5°C / min, hold for 1 hour, and air cool to 100°C;

[0026] 7) Immediately after step 6, use a flux-cored wire containing WC to overlay weld the working area of ​​the bucket teeth to obtain titanium-containing wear-resistant bucket teeth for peeling bucket excavators.

[0027] In this embodiment, the quenching process using water cooling + oil cooling is effective. reduceDuring the quenching process, the bucket tooth matrix cracks. Subsequent low-temperature tempering eliminates internal stress while maintaining high hardness. This production process offers good continuity, avoiding the hardness reduction and cost increase caused by secondary heating during welding. Testing of the titanium-containing low-carbon alloy steel bucket tooth samples of this invention revealed an average hardness of 48 HRC for the matrix core and surface, tensile strength ≥1500 MPa, room-temperature impact resistance ≥20 J / cm², and a weld overlay hardness ≥63 HRC. Furthermore, the weld overlay is firmly bonded to the matrix and exhibits strong resistance to spalling. Industrial verification tests on the bucket teeth showed no spalling of the weld overlay. The bucket teeth manufactured using the above production process exhibit excellent wear resistance and a long service life under the stripping conditions of bucket wheel excavators. Industrial testing at an open-pit mine in Inner Mongolia verified that the service life is increased by more than 30% compared to commonly used bucket teeth in stripping bucket wheel excavators, with no fracture failure, demonstrating high economic value. Example 2

[0028] The difference between this embodiment and Embodiment 1 is that the titanium-containing wear-resistant bucket teeth used include a low-carbon alloy steel matrix, the composition of which is as follows: the low-carbon alloy steel matrix includes the following percentage components: C 0.19%, Si 0.75%, Cr 1.5%, Mn 0.85%, Mo 0.3%, Ti 0.1%, Ni 0.7%, S ≤0.01%, P ≤0.02%, with the remainder being Fe and unavoidable impurities.

[0029] The production process is as follows:

[0030] 1) Raw materials are prepared according to the element content ratio of the bucket teeth and melted in an electric furnace to obtain molten iron;

[0031] 2) Perform S, P, and C removal to control the content of these three elements within the required range;

[0032] 3) During this period, the molten steel is allowed to boil well. After tapping and before casting, the molten steel is used to calm the ladle for 5 minutes to remove inclusions.

[0033] 4) Adjust the temperature of the molten iron to 1450℃, pour and mold it, and open the mold and remove the part when the temperature of the bucket tooth casting drops to 550℃;

[0034] 5) Heat the bucket tooth base casting to 1100℃ and hold for 1.4 hours, then quench it with clean water below 28℃. The water flow rate should be greater than 0.7m / s. When the temperature of the bucket tooth base casting drops to 300℃, transfer the casting to an oil bath at room temperature to cool to room temperature.

[0035] 6) Heat the bucket tooth base casting to 210℃ at a rate of 5℃ / min, hold for 1.2 hours, and then air cool to 105℃;

[0036] 7) Immediately after step 6, use a flux-cored wire containing WC to overlay weld the working area of ​​the bucket teeth to obtain titanium-containing wear-resistant bucket teeth for peeling bucket excavators. Example 3

[0037] The titanium-containing wear-resistant bucket teeth used in this embodiment have the following composition in their low-carbon alloy steel matrix:

[0038] C 0.23%, Si 1%, Cr 2%, Mn 1.1%, Mo 0.5%, Ti 0.2%, Ni 1%, S ≤0.01%, P ≤0.02%, the remainder being Fe and unavoidable impurities.

[0039] The production process is as follows:

[0040] 1) Raw materials are prepared according to the element content ratio of the bucket teeth and melted in an electric furnace to obtain molten iron;

[0041] 2) Perform S, P, and C removal to control the content of these three elements within the required range;

[0042] 3) During this period, the molten steel is allowed to boil well. After tapping and before casting, the molten steel is used to calm the ladle for 5 minutes to remove inclusions.

[0043] 4) Adjust the temperature of the molten iron to 1550℃, pour and mold it, and open the mold and remove the part when the temperature of the bucket tooth casting drops to 650℃;

[0044] 5) Heat the bucket tooth base casting to 1150℃ and hold for 1.6 hours, then quench it with clean water at a temperature below 28℃. The water flow rate should be greater than 0.7m / s. When the temperature of the bucket tooth base casting drops to 330℃, transfer the casting to an oil bath at room temperature to cool to room temperature.

[0045] 6) Heat the bucket tooth base casting to 240℃ at a rate of 5℃ / min, hold for 1.5 hours, and air cool to 110℃;

[0046] 7) Immediately after step 6, use a flux-cored wire containing WC to overlay weld the working area of ​​the bucket teeth to obtain titanium-containing wear-resistant bucket teeth for peeling bucket excavators.

[0047] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method of manufacturing a wear-resistant bucket tooth containing titanium for a ripper wheel bucket excavator, characterized by, The method comprises the following steps: Step 1) melt raw materials in an electric furnace according to the content of the tooth element, and obtain molten iron; Step 2) remove S, P and C, and control the content of the three elements in the required range; Step 3) make the molten steel boil well, and use the molten steel to calm in the ladle for 5-10 minutes before pouring, so as to remove inclusions; Step 4) adjust the temperature of the molten iron to 1500±50℃, and pour into a mold and take out the product after opening the mold; Step 5) quench the tooth base casting; Step 6) low-temperature temper the tooth base casting, the process being: warm the tooth base casting cooled to room temperature to 200-240℃ at a speed of 5℃ / min, keep warm for 1-1.5 hours, and air cool to 100-110℃; Step 7) immediately after step 6), use WC-containing flux-cored wire to build up welding on the working area of the tooth; The titanium-containing wear-resistant tooth for a stripping wheel excavator comprises a titanium-containing low-carbon alloy steel base and a tungsten carbide (WC) build-up welding layer, and the titanium-containing low-carbon alloy steel base comprises the following percentage components: C 0.18-0.23%, Si 0.75-1%, Cr 1.5-2%, Mn 0.85-1.1%, Mo 0.3-0.5%, Ti 0.1-0.2%, Ni 0.7-1%, S ≤0.01%, P ≤0.02%, and the rest is Fe and inevitable impurities.

2. The method of manufacturing a wear-resistant, titanium-containing bucket tooth for a drag wheel bucket excavator as claimed in claim 1, wherein, In step 4), the mold is opened to take out the tooth casting when the temperature of the tooth casting drops to 600±50℃.

3. The method of manufacturing a wear-resistant, titanium-containing bucket tooth for a drag wheel bucket excavator as claimed in claim 1, wherein, In step 5), the quenching process is: warm the tooth base casting to 1100-1150℃ and keep warm for 1.4-1.6 hours, then quench with water below 28℃, the water flow speed needs to be greater than 0.7m / s, and when the temperature of the tooth base casting drops to 300-328℃, the casting is transferred to an oil bath at room temperature to cool to room temperature.