Steel for Plate Rings of Concrete Pump Trucks and Manufacturing Process of Plate Rings

Abstract

The present invention relates to steel for the plate ring of a concrete pump truck, which comprises the following chemical components: C, Si, Mn, Cr, Ni, Mo, V, Cu, Fe; the present invention also relates to a manufacturing process for the plate ring of a concrete pump truck, which is prepared by using the steel for the plate ring of a concrete pump truck, and comprises the following steps: casting a plate ring blank, rough machining the plate ring blank, quenching treatment of the working surface, grinding the surface, rust prevention treatment, and packaging steps. In the preparation process of the plate ring, high-frequency quenching is carried out on the working surface of the plate ring blank, which can improve the hardness of the working surface and further improve the wear resistance of the working surface. Without the action of the wear-resistant alloy elements of the plate ring blank body, even if the hardness of the working surface of the plate ring blank is high, the product will not have good wear resistance and impact resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of wear-resistant plates and cutting rings for concrete pumps (hereinafter referred to as: plate rings), specifically to the steel for plate rings used in concrete pump trucks and the manufacturing process of plate rings. Background Art

[0002] The wear-resistant plates and cutting rings for concrete pump trucks consist of two parts: a shear wear-resistant layer and a steel billet body. Among them, the wear-resistant layer plays a role in resisting wear, impact, and cracking when the wear-resistant plates and cutting rings shear against each other; the steel billet body is the main body for welding and inlaying the wear-resistant layer, mainly for installation and fixation on the pump body. In a concrete delivery pump truck, there is mainly a delivery pump system. In particular, the wear-resistant plates and cutting rings used in the pumping system are important components for concrete shearing and are key vulnerable parts of this equipment. The service life of the wear-resistant plates and cutting rings is an important indicator of the overall quality of the concrete delivery pump truck equipment. Due to the high-pressure concrete passing through the delivery pump port during the delivery process, strong frictional forces will be generated. Moreover, due to the alternating operation of the cutting ring and the wear-resistant plate between the two material delivery holes during the feeding and discharging processes, the shear surface of the wear-resistant plate and the cutting ring needs to withstand frequent impact changes, resulting in the shear surface of the wear-resistant plate and the cutting ring being easily formed with pits or chunks breaking off, and finally leakage of slurry leading to scrapping; the inner wall of the material delivery hole will be severely worn by the high-pressure concrete. This greatly reduces the service life of the wear-resistant plates and cutting rings and the use efficiency of the concrete delivery pump. Therefore, it not only needs to have properties such as impact resistance and fatigue resistance, but also needs to have good wear resistance and cracking resistance.

[0003] Currently, most of the wear-resistant plates and cutting rings used in concrete delivery pump trucks are made by: using a copper brazing electrode to weld and inlay hard alloy blocks together on the steel billet body as the shear wear-resistant surface; and using the surfacing method to enhance the hardness of the inner wall of the material delivery hole. This manufacturing method does have a certain wear resistance, but it has multiple production processes, high costs, and defects such as uneven and inconsistent hardness of the wear-resistant surface and insufficient wear resistance of the inner wall of the material delivery hole. Especially during the use of the product, when the delivery pressure of the delivery pump is high and the impact force is large, the interaction between the wear-resistant plates and the cutting rings will be enhanced. When shearing the concrete slurry, due to the low hardness of the copper brazing electrode material itself used for welding the hard alloy blocks on the wear-resistant surface and the surfacing of the inner wall of the material delivery hole not reaching a relatively high hardness. Therefore, the copper brazing electrode between the hard alloy composite blocks and the inner wall of the material delivery hole are not firmly bonded between the welded hard alloy composites or with the steel billet body, and are easily severely worn at the weld during use, resulting in chunks breaking off or even falling off of the hard alloy composite body. Especially at the nose bridge part of the wear-resistant plate, there will be chunks falling off and fractures; the inner wall of the material delivery hole is severely worn, seriously affecting the service life of the wear-resistant plates and cutting rings and the use efficiency of the concrete pump truck.

[0004] Based on this, the present application proposes a steel for the plate ring of a concrete pump truck and a manufacturing process for the plate ring to solve the above problems. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a steel for the plate ring of a concrete pump truck and a manufacturing process for the plate ring, making the working surface and the body of the plate ring an integral whole. Through the quenching process, the hardness and wear resistance of all working surfaces in contact with concrete are increased, and the quenched layer is as high as 6 - 8 mm, greatly improving the service life of the plate ring.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The steel for the plate ring of a concrete pump truck includes the following chemical components: C, Si, Mn, Cr, Ni, Mo, V, Cu, Fe;

[0008] The weight percentages of its chemical components are respectively: C: 0.45 - 0.5; Si: 0.5 - 0.9; Mn: 0.9 - 1.2; Cr: 1.5 - 1.8; Ni: 0.2 - 0.3; Mo: 0.2 - 0.3; V: 0.2 - 0.3; Cu: 0.1 - 0.3; the rest is Fe; wherein, the depth of the hardened layer of the steel is 6 - 8 mm, and the surface hardness is 60 - 70 HRC.

[0009] The manufacturing process for the plate ring of a concrete pump truck is prepared using the steel for the plate ring of a concrete pump truck as described above, and includes the following steps:

[0010] S1. Casting the blank:

[0011] Melting pure scrap iron into molten steel and then adding other chemical components except scrap iron for smelting to obtain molten steel with qualified chemical components. Pour the qualified molten steel into a mold and cool it into a blank. After cleaning the burrs, place the blank in a heat treatment furnace, heat and keep it warm for a certain period of time, then cool it to room temperature, and polish it before storing it in the warehouse for further processing;

[0012] S2. Rough machining of the blank:

[0013] Rough machine the blank using equipment such as machining centers and CNC lathes according to requirements;

[0014] S3. Local quenching of the semi-finished product:

[0015] Place the rough-machined semi-finished blank in a special quenching equipment to rapidly heat up its working surface, and then spray and cool it quickly to form a quenched layer on the working surface of the semi-finished blank. After quenching, place the blank in a heat treatment furnace and keep it warm for a certain period of time to relieve stress. After cooling to room temperature, polish and paint it;

[0016] S4. Grinding the surface, removing rust and packaging:

[0017] Use a surface grinder to grind the working surface of the painted plate ring part to the specified size, clean the ground plate ring part with rust preventive liquid and package it with heat shrink film for storage in the warehouse;

[0018] The heat treatment temperature in S1 is 900 - 950 °C, and the heat preservation time is 2 - 3 h;

[0019] The cooling in S1 is air cooling;

[0020] The quenching temperature in S3 is 950 - 1100 °C;

[0021] The tempering temperature in S3 is 250 - 300 °C, and the heat preservation time is 2 - 3 h.

[0022] Furthermore, the quenched layer obtained after the working surface of the semi-finished blank in S3 is quenched is specifically: a dense wear-resistant quenched layer with a surface depth of 6 - 8 mm.

[0023] Furthermore, the quenched layer formed on the working surface of the semi-finished blank through the quenching treatment in S3 has a surface hardness of 60 - 70 HRC, and the wear resistance is increased to more than 20 times that before quenching.

[0024] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0025] 1. For the steel used in the plate ring of this concrete pump truck, the chemical composition of the steel is the basis for the subsequent surface quenching of the plate ring blank and improving the service life of the product. The wear resistance and impact resistance of the working surface of the plate ring blank after quenching are closely related to the chemical composition in the blank. The reasonable chemical composition enables the plate ring blank body to have high strength wear resistance and toughness, and also enables the unquenched working surface to have high impact resistance and toughness after quenching. By controlling the chemical composition ratio in the plate ring blank, the mechanical properties of the alloy can be significantly improved, making it more suitable for high-strength, high-load, and high-wear engineering applications.

[0026] 2. For the manufacturing process of the plate ring of this concrete pump truck, the plate ring blank is manufactured by the casting process because appropriate wear-resistant alloy elements can be added during the melting process, enabling the plate ring blank body to have high wear resistance; high-frequency quenching of the working surface of the plate ring blank can increase the hardness of the working surface and further improve the wear resistance of the working surface. Without the effect of the wear-resistant alloy elements in the plate ring blank body, no matter how high the hardness of the working surface of the plate ring blank is, the product will not have good wear resistance. Specific Embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] The present application provides steel for the plate ring of a concrete pump truck, which includes the following chemical components: C, Si, Mn, Cr, Ni, Mo, V, Cu, Fe; the weight percentage range values of its chemical components are respectively: C: 0.45 - 0.5; Si: 0.5 - 0.9; Mn: 0.9 - 1.2; Cr: 1.5 - 1.8; Ni: 0.2 - 0.3; Mo: 0.2 - 0.3; V: 0.2 - 0.3; Cu: 0.1 - 0.3; the rest is Fe.

[0029] Example 1

[0030] The steel for the plate ring of a concrete pump truck includes the following chemical components: C, Si, Mn, Cr, Ni, Mo, V, Cu, Fe; the weight percentages of its chemical components are respectively: C: 0.475; Si: 0.7; Mn: 1.05; Cr: 1.65; Ni: 0.25; Mo: 0.25; V: 0.25; Cu: 0.2; the rest is Fe.

[0031] Example 2

[0032] The weight percentages of the chemical components of the steel for the plate ring in this example are specifically: C: 0.5; Si: 0.9; Mn: 1.2; Cr: 1.8; Ni: 0.3; Mo: 0.3; V: 0.3; Cu: 0.3; the rest is Fe.

[0033] Example 3

[0034] The weight percentages of the chemical components of the steel for the plate ring in this example are specifically: C: 0.45; Si: 0.5; Mn: 0.9; Cr: 1.5; Ni: 0.2; Mo: 0.2; V: 0.2; Cu: 0.1; the rest is Fe.

[0035] Comparative Example 1

[0036] Compared with Example 1, the chemical composition of the steel for the plate ring in this comparative example has the value range of the chemical component Ni exceeding the lower limit by 0.1, and the rest of the chemical components and the weight percentages of the chemical components are the same as those in Example 1.

[0037] Comparative Example 2

[0038] The chemical composition of the steel for the plate ring in this comparative example, compared with that in Example 1, has the numerical range of the chemical composition Ni exceeding the upper limit by 0.1, and the remaining chemical compositions and the weight percentages of the chemical compositions are the same as those in Example 1.

[0039] Comparative Example 3

[0040] The chemical composition of the steel for the plate ring in this comparative example, compared with that in Example 1, replaces the chemical composition V with Nb, and the weight percentage of the Nb chemical composition is 0.25, and the remaining chemical compositions and the weight percentages of the chemical compositions are the same as those in Example 1.

[0041] Comparative Example 4

[0042] The chemical composition of the steel for the plate ring in this comparative example, compared with that in Example 1, replaces the chemical composition Cu with Al, and the weight percentage of the Al chemical composition is 0.2, and the remaining chemical compositions and the weight percentages of the chemical compositions are the same as those in Example 1.

[0043] Comparative Example 5

[0044] The chemical composition of the steel for the plate ring in this comparative example, compared with that in Example 1, has the numerical range of the chemical composition Mo exceeding the lower limit by 0.1, and the remaining chemical compositions and the weight percentages of the chemical compositions are the same as those in Example 1.

[0045] Comparative Example 6

[0046] The chemical composition of the steel for the plate ring in this comparative example, compared with that in Example 1, has the numerical range of the chemical composition Mo exceeding the upper limit by 0.1, and the remaining chemical compositions and the weight percentages of the chemical compositions are the same as those in Example 1.

[0047] The weight percentage range values of the chemical composition of the steel for the plate ring of the concrete pump truck given in this application are respectively: C: 0.45 - 0.5; Si: 0.5 - 0.9; Mn: 0.9 - 1.2; Cr: 1.5 - 1.8; Ni: 0.2 - 0.3; Mo: 0.2 - 0.3; V: 0.2 - 0.3; Cu: 0.1 - 0.3.

[0048] For the above Examples 1 - 3 and Comparative Examples 1 - 6, the same batch of scrap iron was used and the manufacturing process of the plate ring for the concrete pump truck provided in Example 4 of this application was applied for preparation. The wear resistance test method of GB / T34501 - 2017, the Rockwell hardness test method for metallic materials - Part 1: Test method of GB / T230.1 - 2018, and the room - temperature impact toughness test method of cemented carbide of GB / T1817 - 2017 were adopted to measure the wear resistance, hardness performance and impact toughness indexes of the plate ring specimens of Examples 1 - 3 and Comparative Examples 1 - 6 for convenient evaluation.

[0049] The test results are shown in the following table:

[0050]

[0051] Based on the analysis of the test data of Examples 1 - 3 and Comparative Examples 1 - 6, the following conclusions can be drawn: The volumetric wear of Example 1 and Example 3 is relatively small, indicating that these two chemical compositions have good wear resistance. While the volumetric wear of Example 2 is relatively large, indicating that the wear resistance of this chemical composition is lower than that of Example 1 and Example 3. The volumetric wear of Comparative Example 1 and Comparative Example 2 both significantly exceed that of Example 1, and the volumetric wear of Comparative Example 3 is slightly higher than that of Example 1, which shows that the change in the chemical composition and its proportion range proposed in this application will have a certain impact on wear resistance. At the same time, the volumetric wear of Comparative Example 4, Comparative Example 5, and Comparative Example 6 is also relatively large, indicating that the change in the chemical composition and its proportion range proposed in this application for Cu and Mo elements will have a certain impact on wear resistance.

[0052] The average hardness values of Example 1 and Example 2 are relatively high, while the average hardness value of Example 3 is relatively low. The hardness values of Comparative Example 1, Comparative Example 2, and Comparative Example 3 are all significantly low, indicating that the change in the chemical composition and its proportion range proposed in this application for Ni and V elements will have an impact on hardness performance. The hardness values of Comparative Example 4 and Comparative Example 5 are relatively high, indicating that the change in the chemical composition and its proportion range proposed in this application for Cu and Mo elements will have a certain impact on hardness performance. The hardness value of Comparative Example 6 is close to that of Example 1, indicating that the increase in the chemical composition and its proportion range proposed in this application for Mo element has a relatively small impact on hardness performance.

[0053] The impact toughness values of Example 1, Example 2, and Example 3 are 265 J / cm 2 、193 J / cm 2 and 239 J / cm 2 respectively. The impact toughness values of Comparative Example 1, Comparative Example 2, and Comparative Example 3 are 126 J / cm 2 、156 J / cm 2 and 157 J / cm 2 respectively. It can be seen that the impact toughness value of Example 1 is the highest, while the impact toughness values of Comparative Example 1, Comparative Example 2, and Comparative Example 3 are significantly reduced. This shows that the change in the chemical composition and its proportion range proposed in this application for Ni and V elements will have a greater impact on impact toughness.

[0054] In summary, after considering the parameters exceeding those of Comparative Example 3 and Comparative Example 4, Example 3 is still the best chemical composition obtained within the specified parameter range. However, it should be noted that the introduction of parameters exceeding the range may have some unpredictable impacts on the performance of the plate ring. Therefore, to ensure the performance and stability of the plate ring, it is recommended to still design and optimize the chemical composition within the parameter range specified in this application.

[0055] This application also provides a manufacturing process for the plate ring of a concrete pump truck, which is prepared using the steel for the plate ring of a concrete pump truck as described above, and includes the following steps:

[0056] S1. Preparation of the blank:

[0057] Pure scrap iron is melted into molten steel, and then the remaining chemical components other than iron and steel are added for melting to obtain improved molten steel. The improved molten steel is poured into a mold and cooled into a blank. After cleaning the burrs, the blank is placed in a heat treatment furnace, heated and kept warm for a certain period of time, and then cooled to room temperature. After polishing, it is stored in the warehouse for processing.

[0058] S2. Rough machining of the alloy:

[0059] The blank is rough machined using equipment such as a machining center and a CNC lathe according to requirements.

[0060] S3. Heat treatment:

[0061] The rough machined blank is placed in a quenching device, rapidly heated up and then sprayed with cooling water for rapid cooling. After quenching, the plate ring blank is placed in a heat treatment furnace and kept warm for a certain period of time, and then polished and painted after being cooled to room temperature.

[0062] S4. Grinding, rust removal and packaging:

[0063] The painted plate ring blank is ground to the specified size using a surface grinder, cleaned with an anti-rust liquid, and packaged with heat shrink film and then stored in the warehouse.

[0064] Preferably, the heat treatment temperature in S1 is 900 - 950 °C, and the heat preservation time is 2 - 3 h.

[0065] Preferably, the cooling in S1 is air cooling.

[0066] Preferably, the quenching temperature in S3 is 950 - 1100 °C.

[0067] Preferably, the tempering temperature in S3 is 250 - 300 °C, and the heat preservation time is 2 - 3 h.

[0068] Preferably, the quenching layer obtained after the working surface of the semi-finished blank in S3 is quenched is specifically a dense wear-resistant quenching layer with a surface depth of 6 - 8 mm.

[0069] Preferably, the surface hardness of the quenching layer formed on the working surface of the semi-finished blank through the quenching treatment in S3 reaches 70 - 75 HRC, and the wear resistance is increased to more than 20 times that before quenching.

[0070] Example 4

[0071] The manufacturing process of the plate ring for concrete pumps, which is prepared using the steel for the plate ring of the concrete pump vehicle in Example 1, includes the following steps:

[0072] S1. Casting the blank:

[0073] a) Use pure and homogeneous steel, melt it into molten steel through an intermediate frequency electric furnace, and add other chemical composition materials except scrap iron in sequence during the melting process of the molten steel to obtain molten steel with qualified chemical composition;

[0074] b) Pour the molten steel with qualified chemical composition obtained after melting into a coated sand mold shell to form a plate ring blank. After cooling the plate ring blank, remove the riser and burrs;

[0075] c) Put the plate ring blank into a heat treatment furnace, heat it to 925 °C, keep it warm in the furnace for 2.5 h, then air-cool the blank to room temperature, and after shot blasting and sand cleaning treatment, store it in the warehouse for further processing;

[0076] S2. Rough machining of the blank:

[0077] Machine the plate ring blank to the corresponding required dimensions using equipment such as machining centers and CNC lathes according to the drawing requirements;

[0078] S3. Local quenching of the semi-finished product:

[0079] a) Place the rough-machined plate ring blank on a special quenching equipment, use this quenching equipment to quickly heat the wear-resistant working surface of the blank to 1025 °C, and then spray cooling liquid to quickly cool the heated surface of the plate ring blank;

[0080] b) Put the quenched plate ring blank into the heat treatment furnace again, heat it to 275 °C, keep it warm for 2.5 h to remove stress from the plate ring, and after natural cooling, perform shot blasting treatment again to clean the oxide scale on the surface, and spray anti-rust paint;

[0081] S4. Grinding the surface, removing rust and packaging:

[0082] Grind the working surface of the heat-treated and painted plate ring flat with a surface grinder until it reaches the dimensions specified in the drawing, then clean the ground plate ring with a volatile rust inhibitor, and then package it with heat shrink film and store it in the warehouse.

[0083] Example 5

[0084] The manufacturing process of the plate ring for concrete pump vehicles, which is prepared using the steel for the plate ring of the concrete pump vehicle in Example 1, includes the following steps:

[0085] S1. Casting the blank:

[0086] a) Use pure steel throughout, melt it into molten steel through an intermediate frequency electric furnace, and add other chemical composition materials except scrap iron in sequence during the melting process of the molten steel to obtain molten steel with qualified chemical composition;

[0087] b) Pour the molten steel with qualified chemical composition obtained from melting into a coated sand mold shell to form a blank of the plate ring. After cooling the blank of the plate ring, remove the riser and burrs;

[0088] c) Put the blank of the plate ring into a heat treatment furnace, heat it to 900 °C, keep it warm in the furnace for 2 h, then air-cool the blank to room temperature, and after shot blasting and sand cleaning, store it in the warehouse for further processing;

[0089] S2. Rough machining of the blank:

[0090] Process the blank of the plate ring to the corresponding required dimensions using equipment such as a machining center and a CNC lathe according to the requirements of the drawing;

[0091] S3. Local quenching of the semi-finished product:

[0092] a) Place the rough machined blank of the plate ring on a dedicated quenching device, use the quenching device to quickly heat the wear-resistant working surface of the blank to 950 °C, and then spray a cooling liquid to quickly cool the heated surface of the blank of the plate ring;

[0093] b) Put the quenched blank of the plate ring into the heat treatment furnace again, heat it to 250 °C, keep it warm for 2 h to remove stress from the plate ring, naturally cool it, and then perform shot blasting again to clean the oxide scale on the surface, and spray anti-rust paint;

[0094] S4. Grinding, rust removal and packaging:

[0095] Grind the working surface of the plate ring after heat treatment and painted with a surface grinder until it reaches the size specified in the drawing, then clean the ground plate ring with a volatile rust preventive liquid, and then package it with heat shrink film and store it in the warehouse.

[0096] Example 6

[0097] The manufacturing process of the plate ring for a concrete pump truck, which is prepared by using the steel for the plate ring of a concrete pump truck in Example 1, includes the following steps:

[0098] S1. Casting the blank:

[0099] a) Use pure steel throughout, melt it into molten steel through an intermediate frequency electric furnace, and add other chemical composition materials except scrap iron in sequence during the melting process of the molten steel to obtain molten steel with qualified chemical composition;

[0100] b) Pour the molten steel with qualified chemical composition obtained from melting into a coated sand mold shell to form a blank of the plate ring. After cooling the blank of the plate ring, remove the riser and burrs;

[0101] c) Place the blank of the plate ring into a heat treatment furnace, heat it to 950 °C, keep it in the furnace for 3 h, then air-cool the blank to room temperature, and after shot blasting and sand cleaning, store it in the warehouse for further processing;

[0102] S2. Rough machining of the blank:

[0103] Machine the blank of the plate ring to the corresponding required dimensions using equipment such as machining centers and CNC lathes according to the drawing requirements;

[0104] S3. Local quenching of the semi-finished product:

[0105] a) Place the rough-machined blank of the plate ring on a dedicated quenching device, use this quenching device to quickly raise the temperature of the wear-resistant working surface of the blank to 1100 °C, and then spray cooling liquid to quickly cool the heated surface of the plate ring blank;

[0106] b) Put the quenched blank of the plate ring into the heat treatment furnace again, heat it to 300 °C, keep it for 3 h to remove stress from the plate ring, and after natural cooling, perform shot blasting again to clean the oxide scale on the surface, and spray anti-rust paint;

[0107] S4. Grinding, rust removal and packaging:

[0108] Grind the working surface of the plate ring after heat treatment and painted with paint using a surface grinder until it reaches the dimensions specified in the drawing, then clean the ground plate ring with volatile rust preventive liquid, and then package it with heat shrink film and store it in the warehouse.

[0109] Comparative Example Seven

[0110] Compared with Example 4, in the plate ring manufacturing process of this comparative example, the upper limit of the quenching temperature in S3 is increased by 100 °C, and the other manufacturing processes are the same as those in Example 4.

[0111] Comparative Example Eight

[0112] Compared with Example 4, in the plate ring manufacturing process of this comparative example, the lower limit of the quenching temperature in S3 is decreased by 100 °C, and the other manufacturing processes are the same as those in Example 4.

[0113] Comparative Example Nine

[0114] Compared with Example 4, in the plate ring manufacturing process of this comparative example, the upper limit of the temperature in step a of S3 is increased by 50 °C, and the other manufacturing processes are the same as those in Example 4.

[0115] Comparative Example Ten

[0116] Compared with Example 4, in the plate ring manufacturing process of this comparative example, the lower limit of the temperature in step a of S3 is decreased by 50 °C, and the other manufacturing processes are the same as those in Example 4.

[0117] For the above-mentioned Examples 5-6 and Comparative Examples 7-10, the same batch of scrap iron was used and the steel for the plate ring of the concrete pump truck provided in Example 1 was used for preparation. The wear resistance test method of GB / T 34501-2017 and the carbide normal temperature impact toughness test method of GB / T 1817-2017 were adopted to measure the wear resistance and impact toughness indexes of the plate ring specimens of Examples 4-6 and Comparative Examples 7-10 for convenient evaluation.

[0118] The test results are shown in the following table:

[0119]

[0120] The following analysis can be drawn from the above data:

[0121] The volume wear amount of Example 4 is 0.0010 m 3 , and the volume wear amount of Comparative Example 10 is 0.0040 m 3 . This shows that in the manufacturing process of the plate ring for the concrete pump truck in this application, Example 4 has a lower volume wear amount than Comparative Example 10, that is, better wear resistance. Similarly, Examples 5 and 6 also have lower volume wear amounts than Comparative Examples 7-10, which shows the improvement in wear resistance of the manufacturing processes of the plate rings for the concrete pump truck in Examples 5 and 6 compared with Comparative Examples 7-10.

[0122] The impact toughness value of Example 4 is 196 J / cm 2 , and the impact toughness value of Comparative Example 10 is 152 J / cm 2 . This shows that in the manufacturing process of the plate ring for the concrete pump truck in this application, Example 4 has higher impact toughness than Comparative Example 7, that is, better impact resistance. Similarly, Examples 5 and 6 also have higher impact toughness than Comparative Examples 7-9, showing the improvement in impact resistance of the manufacturing processes of the plate rings for the concrete pump truck in Examples 5 and 6 compared with Comparative Examples 7-10.

[0123] Based on the above analysis, the following conclusions can be drawn:

[0124] The volume wear amount and impact toughness value of Comparative Example 7 and Comparative Example 8 are significantly lower than those of other examples. This may be due to the change in the temperature range. Therefore, by analyzing the test results, we can conclude that in the manufacturing process of the plate ring for the concrete pump truck, maintaining the heat treatment steps and parameter ranges specified in this application is crucial for improving the wear resistance and impact toughness value of the plate ring.

[0125] The impact toughness values of Comparative Example 9 and Comparative Example 10 are relatively higher than those of Comparative Example 7 and Comparative Example 8, and the volume wear amounts of Comparative Example 9 and Comparative Example 10 are relatively lower than those of Comparative Example 7 and Comparative Example 8, indicating that Comparative Example 9 and Comparative Example 10 are superior to Comparative Example 7 and Comparative Example 8. Through the study of Comparative Example 7 and Comparative Example 8, it is found that when the values exceed the upper and lower limits of the given range of the manufacturing process of the plate ring for concrete pumps, the volume wear amount and impact toughness value of the plate ring will be relatively low. Furthermore, it can be further determined that each step in the manufacturing process has an important impact on the alloy properties.

[0126] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0127] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Steel for the plate ring of a concrete pump truck, characterized in that, It includes the following chemical components: C, Si, Mn, Cr, Ni, Mo, V, Cu, Fe; The weight percentages of its chemical components are respectively: C：0.45-0.5； Si: 0.5 - 0.9; Mn: 0.9 - 1.2; Cr：1.5-1.8； Ni: 0.2 - 0.3; Mo: 0.2 - 0.3; V：0.2-0.3； Cu: 0.1 - 0.3; The rest is Fe; wherein, the hardened layer depth of the steel is 6 - 8 mm, and the surface hardness is 60 - 70 HRC.

2. The manufacturing process of the plate ring for a concrete pump truck, characterized in that, It is prepared by using the steel for the plate ring of the concrete pump truck as described in Claim 1, and includes the following steps: S1. Casting blank: Melting pure scrap iron into molten steel, then adding other chemical components except scrap iron for smelting to obtain molten steel with qualified chemical components, pouring the molten steel with qualified chemical components into a mold and cooling it into a blank, cleaning the burrs, then placing the blank in a heat treatment furnace, heating and holding it for a certain period of time and then cooling it to room temperature, and finally storing it in the warehouse for processing after polishing; S2. Rough machining of the blank: Rough machining the blank with equipment such as machining centers and CNC lathes as required; S3. Local quenching of the semi-finished product: Placing the rough-machined semi-finished product blank in a special quenching equipment to rapidly heat up its working surface, and then spraying and cooling it rapidly to form a quenched layer on the working surface of the semi-finished product blank. After quenching, placing the blank in a heat treatment furnace and holding it for a certain period of time to relieve stress, and after cooling to room temperature, polishing and painting it; S4. Grinding the surface and anti-rust packaging: Using a surface grinder to grind the working surface of the plate ring part with paint applied to the specified size, cleaning the ground plate ring part with an anti-rust liquid and packaging it with a heat shrinkable film and storing it in the warehouse; The heat treatment temperature in S1 is 900 - 950 °C, and the holding time is 2 - 3 h; The cooling in S1 is air cooling; The quenching temperature in S3 is 950 - 1100 °C; The tempering temperature in S3 is 250 - 300 °C, and the holding time is 2 - 3 h.

3. The manufacturing process of the plate ring for a concrete pump truck according to claim 2, characterized in that: The quenched layer specifically obtained after the working surface of the semi-finished product blank in S3 is quenched is: a dense and wear-resistant quenched layer with a surface layer depth of 6 - 8 mm.

4. The manufacturing process of the plate ring for a concrete pump truck according to claim 2, characterized in that: The quenched layer formed on the working surface of the semi-finished product blank through the quenching treatment in S3 has a surface hardness reaching 60 - 70 HRC, and the wear resistance is increased to more than 20 times that before quenching.

Images