Shot blasting machine lifting appliance and manufacturing method thereof

Abstract

The invention provides a shot blasting machine lifting appliance and a manufacturing method thereof, and aims to overcome the defects of an existing lifting appliance in the aspects of wear resistance and service life. Specifically, the lifting appliance of the shot blasting machine comprises the following components in percentage by mass: 3.1-3.7% of C, 2.8-3.6% of Si, 1.8-2.5% of Mn, less than or equal to 0.015% of S, less than or equal to 0.03% of P, 0.3-0.6% of Cu, 0.2-0.35% of Cr, 0-0.5% of Mo and the balance of Fe and inevitable impurities, and is supplemented with a fine casting and heat treatment process. The metallographic structure of the lifting appliance is optimized, the wear resistance of the lifting appliance is remarkably improved, and the overall service life of the lifting appliance is remarkably prolonged. The verification result of the embodiment shows that the service life of the shot blasting machine lifting appliance manufactured through the method can reach 8-10 months under the condition that the shot blasting machine lifting appliance works for 5 hours every day, and the service life of the shot blasting machine lifting appliance is far longer than the service life of a traditional lifting appliance which is 3 months. In addition, the wear resistance of the lifting appliance is excellent, the replacement frequency and the maintenance cost are effectively reduced, and a powerful guarantee is provided for efficient and stable operation of the shot blasting machine. The method not only has remarkable technical advantages, but also brings considerable economic benefits, and has wide application prospects and popularization value.

Description

Technical Field

[0001] The invention relates to a chemical composition of a hanger material for a shot blasting machine and a production method thereof, belonging to the technical field of metal material casting. Background Art

[0002] In the machinery manufacturing industry, surface shot blasting, as an important metal surface treatment technology, is widely used to improve the surface quality of parts, enhance wear resistance and extend service life. In this process, the importance of the hanger as a key component connecting the shot blasting machine and the treated parts is self-evident. The hanger needs to be placed in the shot blasting room together with the treated parts to withstand the strong impact and cutting from high-speed steel shots or steel segments. Therefore, its wear resistance becomes an important indicator to measure the performance of the hanger.

[0003] However, the current selection and manufacturing of sling materials face many challenges. Traditionally, high-chromium cast iron is not suitable for manufacturing slings due to its brittle characteristics and easy to break when bumped. Although steel welded slings are relatively low in cost, they are not wear-resistant enough and have a short service life. Frequent replacement of slings not only increases maintenance costs, but also seriously affects the continuity and efficiency of production. Although low-alloy wear-resistant steels have improved wear resistance to a certain extent, the improvement is limited; and high-alloy wear-resistant steels are difficult to promote widely in the field of shot blasting due to their high prices. In addition, as a potential sling material, high manganese steel has high technical requirements for the production of castings, which ordinary cast iron manufacturers are unable to meet, and the cost of purchasing high manganese steel slings is high, which is not economically cost-effective.

[0004] In view of the above situation, it is particularly important to develop a method for producing a hanger for a shot blasting machine that is both wear-resistant and economical and practical. Based on this demand, the present invention proposes a new technology that uses wear-resistant ductile iron as the hanger material and obtains excellent wear-resistant metallographic structure and improves wear resistance through special heat treatment or casting post-treatment methods. This innovation is not only expected to solve the problem of easy wear and frequent replacement of hangers, but also effectively reduce production costs and improve the production efficiency and economic benefits of shot blasting. Summary of the invention

[0005] The present invention aims to solve the problems of poor wear resistance, short service life and high production cost of existing shot blasting machine hangers. By developing a shot blasting machine hanger and a manufacturing method thereof, the present invention provides a shot blasting machine hanger with excellent wear resistance and toughness, while reducing production costs and improving production efficiency.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: A shot blasting machine hanger, characterized in that the shot blasting machine hanger is obtained by a casting method, and its chemical composition is carefully designed, including the following elements by mass percentage: C=3.1-3.7%, Si=2.8-3.6%, Mn=1.8-2.5%, S≤0.015, P%≤0.03, Cu%=0.3-0.6, Cr%=0.2-0.35%, Mo=0-0.5%, and the balance is Fe and unavoidable impurities. This chemical composition design optimizes the casting performance of molten iron by slightly reducing the carbon content (C=3.1-3.7%) to maintain a reasonable carbon equivalent. At the same time, increasing the silicon content (Si=2.8-3.6%) helps to reduce the risk of manganese precipitation at the grain boundary to form a network structure, thereby enhancing the toughness of the casting. Increasing the manganese content beyond the normal range (Mn=1.8~2.5%) and adding trace amounts of copper, molybdenum and chromium, the synergistic effect of these elements causes the cooling transformation C curve of ductile iron after pouring and heat treatment to shift to the right, improving the hardenability, facilitating the acquisition of bainite structure, and significantly improving the wear resistance and toughness of the sling.

[0007] Furthermore, the present invention adopts a sand casting method to manufacture the sling, and during the casting process, multiple inoculation treatments are also performed, including adding inoculants when the molten iron is out of the furnace and when pouring, and spheroidizing treatment to obtain a spheroidal graphite structure, thereby further improving the mechanical properties and wear resistance of the sling.

[0008] The specific casting process is as follows: (1) Melting and inoculation treatment: Various raw materials weighed according to the designed chemical composition ratio are put into the melting furnace, heated to completely melt the raw materials, and form molten iron that meets the chemical composition requirements. (2) Spheroidizing treatment: The molten iron with qualified smelting chemical composition is spheroidized after it is taken out of the furnace, and the amount of spheroidizing agent added is 1-1.5%. Inoculation treatment is carried out at the same time as spheroidizing treatment to obtain a spheroidal graphite structure. Spheroidal graphite can significantly improve the toughness of the hanger and reduce cracks and fractures caused by external impact. (3) Casting method: The sand casting method is used. While performing step (2), the molding is carried out and the treated molten iron is poured into the prepared sand mold. During the pouring process, inoculation treatment can be carried out again to ensure the quality of the molten iron.

[0009] In addition, the present invention also pays special attention to the heat treatment process of the sling. The heat treatment process is specifically as follows: (1) Quenching treatment: the cast sling is placed in a heat treatment furnace, heated to 880°C~950°C and kept warm for a certain period of time. Then it is taken out of the furnace for blowing and water mist treatment, and rapidly cooled to 250°C~400°C. (2) Tempering treatment: the quenched sling is immediately placed in a heat treatment furnace, and kept warm for 3 to 6 hours in the temperature range of 330°C~380°C, so that the metallographic structure of the sling undergoes sufficient phase transformation, and the quenching stress is eliminated, thereby improving the toughness and service life of the sling. After tempering treatment, the metallographic structure of the sling is mainly bainite, and it has excellent wear resistance and toughness.

[0010] For enterprises that do not have heat treatment conditions, the present invention also provides an alternative solution: after pouring molten iron, when the temperature of the hanger drops to 830-960°C, immediately open the box to shake off the sand, and place it in a ventilated place in the workshop or in the open air, use an industrial fan to blow strong air and add water spray to cool it down, so that the hanger is quickly cooled to about 350°C, and then buried in the molding sand and slowly cooled to room temperature. This method can also enable the hanger to obtain the required metallographic structure and performance.

[0011] In order to improve the wear resistance of the sling, when spraying water mist after the sling is quenched out of the furnace or after pouring and high-temperature unpacking, the water spraying amount can be increased to form martensite on the surface of the sling. During tempering, it is carried out according to the lower limit mentioned above, and lower bainite can be formed inside the sling, which can further improve the wear resistance of the sling.

[0012] The beneficial effects of the present invention are as follows: Through scientific chemical composition design and special production method, the shot blasting machine hanger of the present invention can easily obtain bainite structure under production conditions, so as to have good wear resistance and toughness; The spheroidization treatment of molten iron makes the castings have excellent toughness while maintaining good wear resistance, and it is not easy to break during production; Compared with existing slings made of various materials, the sling of the present invention not only has good wear resistance and long service life (up to 8 months, while the service life of a manganese steel welded sling is only 3 months), but also has low production cost and is easy to manufacture.

[0013] The production method of the present invention is simple and feasible, and is applicable to both enterprises with heat treatment conditions and enterprises without heat treatment conditions, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the production roadmap of shot blasting machine hanger.

[0015] Figure 2 This is a shot blasting machine hanger 1 casting drawing.

[0016] Figure 3 This is the casting diagram of shot blasting machine hanger 2. DETAILED DESCRIPTION

[0017] (1) Design and ingredients: First, according to the size and performance requirements of the shot blasting machine sling required by the user, design the chemical composition and shape structure of the sling, draw detailed drawings, and make molds for modeling. The chemical composition is carefully designed, including but not limited to the following mass percentage elements: C=3.1~3.7%, Si=2.8~3.6%, Mn=1.8~2.5%, and appropriate amounts of S, P, Cu, Cr, Mo, etc., and the balance is Fe and unavoidable impurities. According to the design, accurately weigh various raw materials.

[0018] (2) Melting and spheroidizing: Put the ingredients into the smelting furnace and heat them until the raw materials are completely melted to form molten iron that meets the chemical composition requirements. The smelted molten iron is spheroidized after it is taken out of the furnace. The amount of spheroidizing agent added is 1-1.5%. At the same time as the spheroidizing treatment, inoculation treatment is carried out to obtain a spheroidal graphite structure to further enhance the toughness of the hanger.

[0019] (3) Casting: Sand casting is used to mold the iron at the same time as step (2). The treated molten iron is poured into the prepared sand mold. During the pouring process, inoculation treatment can be performed again to ensure the quality of the molten iron.

[0020] (4) Heat treatment: The sling of the shot blasting machine is subjected to a specific heat treatment to obtain the required metallographic structure and performance. The heat treatment process is as follows: the sling is cast and loaded into a heat treatment furnace; the temperature is raised to 880℃~950℃ and kept at this temperature for 2~4 hours; after being taken out of the furnace, the sling casting is blown and sprayed with water mist, and cooled to 250℃~400℃; the sling casting is immediately put into the furnace and kept at a temperature of 330℃~380℃ for 3~6 hours; after being taken out of the furnace, the sling casting can be used. At this time, the sling casting forms a bainite structure with good wear resistance.

[0021] For enterprises that do not have the conditions for heat treatment, the present invention also provides an alternative solution to obtain the desired metallographic structure and performance by controlling the cooling rate of the hanger.

[0022] (5) Inspection and testing: Carry out comprehensive inspection and testing on the manufactured shot blasting machine sling to ensure that the performance indicators such as size, hardness, wear resistance, etc. meet the design requirements.

[0023] Through the above steps, the present invention provides a shot blasting machine hanger with excellent wear resistance and toughness, while reducing production costs, improving production efficiency, and having wide applicability.

[0024] The technical solution of the present invention and the technical effects thereof are further described below through two specific embodiments. Example

[0025] like Figure 2 As shown in the figure, the present invention is applied to a casting rough shot blasting machine in a workshop of our company. The original sling is welded with 25Mn steel plate, and its service life is only 3 months when working 5 hours a day. In order to improve this situation, we use the technical materials proposed in the present invention to produce slings.

[0026] The chemical composition of the hanger is as follows: C=3.3~3.5%, Si=3.1~3.3%, Mn=1.9~2.3%, S≤0.015, P%≤0.03, Cu%=0.35~0.5, Cr%=0.25~0.35%, Mo=0.3~0.4%, and the balance is Fe and unavoidable impurities. The ingredients are mixed according to this chemical composition ratio, and the ingredients are put into the melting furnace for heating and melting to form molten iron that meets the requirements.

[0027] After the molten iron is melted and taken out of the furnace, we use FeSiMg7RE2 spheroidizer to treat the molten iron, adding 1.15% of the weight of the molten iron to promote the spheroidization of graphite and improve the mechanical properties and wear resistance of the hanger. Subsequently, the treated molten iron is poured into the pre-prepared sand mold, and after it is naturally cooled to below 200℃, it is unpacked, sanded and initially polished.

[0028] Next, the hanger blank is heat treated. First, it is placed in a heat treatment furnace and heated to 880-890°C and kept warm for 2 hours. After it is taken out of the furnace, it is immediately cooled rapidly by using a fan and spraying water mist. When the hanger temperature drops to about 350°C, it is immediately placed in a heat treatment furnace and kept warm for 5 hours in the temperature range of 350°C to 380°C for tempering to form a bainite structure with good wear resistance, while eliminating quenching stress and improving toughness. Finally, it is taken out of the furnace and cooled to room temperature, and the hanger is further cleaned and polished.

[0029] After the above treatment, the new spreader was put into production and used. When working 5 hours a day, its service life reached 8 months. Compared with the original spreader, its service life was significantly extended and the effect was good. Example

[0030] like Figure 3 As shown, the present invention is also applied to the small casting shot blasting machine in the second workshop of our company. The original sling is also welded with 25Mn steel plate, and its service life is 3 months when it works 5 hours a day. In order to improve the performance and service life of the sling, we also use the technical materials proposed by the present invention to produce the sling.

[0031] The chemical composition of the sling is the same as that of Example 1, specifically: C=3.3-3.5%, Si=3.1-3.3%, Mn=1.9-2.3%, S≤0.015, P%≤0.03, Cu%=0.35-0.5, Cr%=0.25-0.35%, Mo=0.3-0.4%, and the remainder is Fe and unavoidable impurities. The ingredients are batched and smelted according to this chemical composition ratio to form molten iron that meets the requirements.

[0032] After the molten iron is melted, it is taken out of the furnace and treated with FeSiMg7RE2 spheroidizer, with the addition amount being 1.15% of the weight of the molten iron. Then pouring is carried out, and after pouring, wait for 15 minutes, and unpack when the hanger temperature drops to 830-960℃. After unpacking, shake off the sand, and immediately use a fan to blow air and spray water mist for rapid cooling to quickly form a hard phase structure. When the hanger temperature drops to about 350℃, immediately bury it in the sand and slowly cool it to room temperature, then dig it out and clean and polish it.

[0033] After the above treatment, the new spreader was put into production and used. When working 5 hours a day, its service life reached 10 months. Compared with the original spreader, its service life has been significantly improved and the use effect is good.

[0034] It should be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith can be directly derived or easily associated with by those skilled in the art from the contents disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A shot blasting machine hanger, characterized in that: The shot blasting machine hanger is obtained by a casting method, and the chemical composition of the shot blasting machine hanger includes the following elements in mass percentage: C=3.1-3.7%, Si=2.8-3.6%, Mn=1.8-2.5%, S≤0.015, P%≤0.03, Cu%=0.3-0.6, Cr%=0.2-0.35%, Mo=0-0.5%, and the balance is Fe and unavoidable impurities.

2. A shot blasting machine hanger according to claim 1, characterized in that: The casting method is specifically sand casting.

3. The shot blasting machine hanger according to claim 1 or 2, characterized in that: The shot blasting machine hanger undergoes a specific heat treatment to obtain the required metallographic structure and performance. The heat treatment process is: after the hanger is cast, it is loaded into a heat treatment furnace; the temperature is raised to 880°C to 950°C and kept warm for 2 to 4 hours; after being taken out of the furnace, the hanger casting is blown and sprayed with water mist, cooled to 250°C to 400°C, and the hanger casting is immediately put into the furnace and kept warm at a temperature of 330°C to 380°C for 3 to 6 hours before being taken out of the furnace.

4. The method for manufacturing a hanger for a shot blasting machine according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Design and ingredients: According to the size of the shot blasting machine sling required by the user, design the chemical composition and shape structure of the sling, and draw the drawings. According to the designed chemical composition ratio, weigh the required raw materials; (2) Melting and spheroidizing: Put the ingredients into the smelting furnace and heat them to completely melt the raw materials to form molten iron that meets the chemical composition requirements. The qualified molten iron is taken out of the furnace and spheroidized. At the same time as the spheroidizing treatment, inoculation treatment is carried out to obtain a spheroidal graphite structure to further improve the mechanical properties and wear resistance of the sling; (3) Casting: While carrying out step (2), the processed molten iron is poured into the prepared sand mold, and the hanger blank is obtained after cooling and solidification. During the pouring process, the inoculation treatment can be carried out again to ensure the quality of the molten iron. After cooling, the molten iron is unpacked, sanded and polished to make it smooth; (4) Heat treatment: heat treating the sling blank according to the heat treatment step of claim 3, so that the sling casting forms a bainite structure with good wear resistance; (5) Inspection and testing: The manufactured shot blasting machine sling is comprehensively inspected and tested, including size inspection, hardness test, wear resistance test, etc.

5. The method for manufacturing a hanger for a shot blasting machine according to claim 4, characterized in that: The heat treatment step (4) can also be adjusted as follows: after the molten iron is poured in step (3), when the hanger temperature drops to 830-960°C, the box is immediately opened to shake off the sand, and the hanger is placed in a ventilated place in the workshop or in the open air, and a strong industrial fan is used to blow air and water is sprayed to cool the hanger temperature down to about 350°C, and then the hanger is buried in the molding sand and slowly cooled to room temperature.

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