Nickel alloyed cast iron glass mold and method of making same

Abstract

The application relates to the technical field of glass molds, in particular to a nickel-alloyed cast iron glass mold and a preparation method thereof. The nickel-alloyed cast iron glass mold comprises the following components: C: 3.50-3.65 wt%, Si: 1.70-1.85 wt%, Mn: 0.50-0.70 wt%, Ni: 1.00-1.30%, Cr: 0.36-0.60%, Mo: 0.36-0.50 wt%, S: less than or equal to 0.08 wt%, P: less than or equal to 0.30 wt%, V: less than or equal to 0.05 wt%, Ti: less than or equal to 0.08 wt%, Cu: less than or equal to 1.0 wt%, and the rest is Fe and inevitable impurities. In the application, a proper amount of nickel elements is added, nickel can form high-strength alloys with copper, iron and the like, the alloys finally enter the cast iron, and after annealing treatment, massive pearlite is changed into granular pearlite, the microstructure of the glass mold is changed, the hardness of the glass mold is improved, meanwhile, the glass mold has excellent oxidation and corrosion resistance, the quality of the glass mold is ensured, and the service life of the glass mold is prolonged.

Description

Technical Field

[0001] This application relates to the field of glass mold technology, and in particular to nickel-alloy cast iron glass molds and their preparation methods. Background Technology

[0002] Glass is a material we frequently encounter in daily life, possessing excellent corrosion and acid resistance. Glass bottles and jars are ideal for holding acidic liquids such as juices and beverages. They also offer excellent barrier properties, effectively preventing the intrusion of oxygen and other gases into the contents and preventing volatile components from evaporating into the atmosphere. Furthermore, glass bottles and jars are recyclable. Given current resource scarcity, the use of glass containers is an inevitable trend. High-speed bottle-making machines for producing glass bottles and jars use molds made of either cast iron or copper alloy.

[0003] Although existing glass molds based on cast iron have improved their heat resistance by adding small amounts of elements such as Mn, Ni, Cr, and Mo, their hardness is low, making them prone to cracking and reducing their service life.

[0004] Therefore, improving the hardness of cast iron glass molds is of great significance for the use and development of glassware. Summary of the Invention

[0005] In order to improve the hardness of cast iron glass molds and thus extend their service life, this application provides a nickel-alloyed cast iron glass mold and its preparation method.

[0006] In a first aspect, this application provides a nickel-alloy cast iron glass mold, which adopts the following technical solution: A nickel-alloyed cast iron glass mold comprises the following raw materials in the following proportions: C: 3.50-3.65wt%, Si: 1.70-1.85wt%, Mn: 0.50-0.70wt%, Ni: 1.00-1.30%, Cr: 0.36-0.60%, Mo: 0.36-0.50wt%, S≤0.08wt%, P≤0.30wt%, V≤0.05wt%, Ti≤0.08wt%, Cu≤1.0wt%, with the remainder being Fe and unavoidable impurities.

[0007] By adopting the above technical solution, this application adds an appropriate amount of nickel. Nickel can form high-strength alloys with copper, iron, etc. These alloys are finally incorporated into the cast iron. After annealing, the blocky pearlite is transformed into granular pearlite, which changes the microstructure of the glass mold and thus improves the hardness of the glass mold. At the same time, it gives the glass mold excellent oxidation and corrosion resistance, ensuring the quality of the glass mold and increasing its service life.

[0008] In one specific feasible implementation, the inner cavity of the nickel-alloyed cast iron glass mold is made of type D graphite with a pearlite content of 5%; the core portion is made of type A / D graphite with a pearlite content of 20%. By adopting the above technical solution, the pearlite formed in this application is granular pearlite. Through annealing, the bulk pearlite is spheroidized to form granular pearlite. The surface area of ​​the bulk pearlite is larger than that of the same volume of granular pearlite. However, although the bulk pearlite has high hardness, it is prone to causing the glass mold to crack. The granular pearlite not only further improves the hardness of the glass mold but also makes it less prone to cracking.

[0009] Secondly, this application provides a method for preparing a nickel alloy cast iron glass mold, which adopts the following technical solution: A method for preparing a nickel alloy cast iron glass mold includes the following steps: Raw material preparation: Prepare appropriate quantities of pig iron, scrap steel, recycled materials, ferromanganese, ferrosilicon, and ferronickel as raw materials according to the proportions of each element; Smelting: The raw materials are placed in a smelting furnace and melted to obtain molten iron; Inoculation: Inoculating agent and molten iron are added to the ladle in sequence to obtain inoculated molten iron; Casting: Inoculation block is added into the mold cavity, and the inoculated molten iron is poured into the mold. The molten iron is cooled to obtain a blank. Annealing: The blank is taken out of the mold, heated and kept at the temperature. The annealed blank is cooled with the furnace and then air-cooled to obtain a nickel alloy cast iron glass mold.

[0010] By adopting the above technical solution, the preparation method is simple. The high nickel content, combined with the ordinary spheroidizing annealing process, transforms the blocky pearlite into granular pearlite, which improves the hardness of the glass mold, making it less prone to cracking and extending the service life of the glass mold.

[0011] In one specific implementation, the melting temperature is 1480-1530℃.

[0012] By adopting the above technical solution, the temperature during smelting was optimized, thereby obtaining high-purity molten iron, eliminating the heritability of graphite, and resulting in better performance of the prepared glass mold.

[0013] In one specific implementation, during the inoculation process, the inoculant is a barium silicon inoculant, and the amount of barium silicon inoculant added is 0.3-0.5 wt% of the molten iron.

[0014] By adopting the above technical solution, barium silicon inoculant can increase graphitization nuclei, refine graphite, promote the formation of type A graphite in cast iron, and improve strength. Its addition amount is less than half that of 75% ferrosilicon inoculant, and its anti-fading time is twice that of 75% ferrosilicon inoculant, demonstrating strong anti-fading ability. At the same time, it has a low melting point, making it easy to absorb and melt during inoculation treatment, with very little slag. Its chemical composition is stable, easy to process, with uniform particle size and small deviations in composition and quality.

[0015] The endothermic dissolution of the inoculant in molten iron lowers the temperature of the surrounding area, providing sufficient supercooling conditions for graphite nucleus formation. After dissolution, the inoculant creates a silicon-rich region. Silicon, a graphitization promoter, increases the activity of carbon in the molten iron, facilitating carbon diffusion. This silicon-rich region is in a supersaturated state, making it easier for carbon to aggregate and form graphite nuclei. This effectively reduces the supercooling required for graphite nucleus formation, increasing the number of nuclei formed. The inoculant dissolves gradually in the molten iron, leaving behind numerous tiny ferrosilicon particles. These particles, suspended in the molten iron, act as a heterogeneous nucleus substrate for graphite nucleus formation, significantly reducing the energy fluctuations required for nucleation and lowering the supercooling required for graphite nucleation. By optimizing the amount of inoculant added, the resulting cast iron exhibits good fluidity, reduced shrinkage, improved machinability, and reduced residual stress, resulting in better mechanical properties.

[0016] In one specific implementation, the incubation temperature is 1430-1450℃ and the incubation time is 2 minutes.

[0017] By adopting the above technical solution, the inoculation temperature and time should ensure that the inoculant dissolves rapidly in the molten iron during the inoculation process, and that a concentration difference exists in the microstructure, guaranteeing the formation of sufficient crystal nuclei during the subsequent cooling and solidification process. If the inoculation temperature is too high, the solidification time of the molten iron will be long, easily leading to inoculation degradation; however, if the inoculation temperature is too low, it will also hinder the dissolution and absorption of the inoculant and affect the fluidity of the molten iron. Optimizing the inoculation temperature and time results in better performance of the cast iron.

[0018] In one specific implementation, during the casting process, the amount of the inoculum block added is 2-3 wt% of the molten iron.

[0019] By adopting the above technical solution, the melting process of the inoculant block is carried out simultaneously with the pouring process, achieving uniform inoculation to improve the internal comprehensive performance of the casting, eliminate white iron, and reduce annealing costs. The inoculant block inside the mold is made into a hollow structure with a protruding male mold head, so the compressive strength of the inoculant block is higher than that of a solid inoculant block. It has the largest surface area and the largest heating area in contact with the initial molten iron entering the mold cavity. The hollow cavity at the top center of the inoculant block heats up quickly, so the melting speed is fast. In the closed and semi-closed gating system, the inoculant block melts layer by layer from the surface to the inside without collapsing into blocks. This not only ensures that the molten iron is fully inoculated in the initial stage of entering the mold, but also ensures the uniformity of the inoculant melting. Therefore, it can meet the inoculation requirements of complex parts with short pouring time and low pouring temperature, as well as castings with multiple castings in one mold.

[0020] In one specific implementation, the pouring temperature is 1370-1380℃ and the pouring time is 5-10 minutes.

[0021] By adopting the above technical solutions, controlling the pouring temperature and time can ensure the inclusion of iron oxides, the suppression and expansion of porosity, the elimination of graphite inheritance, and the stabilization of chemical composition fluctuations. Higher pouring temperatures make castings more prone to shrinkage cavities, porosity, pitting, and deformation defects; while lower pouring temperatures can lead to incomplete filling and cold shuts. If the pouring time for a ladle of molten iron is too long, both excessively high and excessively low pouring temperatures will occur in the castings produced. High-temperature pouring defects occur in the early stages of pouring due to the high temperature, while low-temperature pouring defects occur in the later stages. Therefore, it is crucial to control the pouring time during production. Controlling the pouring time appropriately is beneficial for the quality of the cast iron. The longer the pouring time, the more inoculant elements are burned off, and the inoculant elements in the cast iron degrade with prolonged pouring time. Therefore, optimizing the pouring temperature and time results in better performance of the resulting cast iron.

[0022] In one specific implementation scheme, during the annealing process, the blank is heated to 953-957°C and held for 10 hours, then cooled in the furnace to 500°C before being removed from the furnace and air-cooled to room temperature.

[0023] By adopting the above technical solutions, the internal stress of the material matrix can be removed, the plasticity and toughness of the material can be improved, and the processing performance of the material can be enhanced. Optimizing the temperature and time during annealing can transform the matrix structure from blocky pearlite to granular pearlite, thereby increasing the hardness of the cast iron glass mold and making it less prone to cracking.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. This application adds an appropriate amount of nickel. Nickel can form high-strength alloys with copper, iron, etc. These alloys are finally incorporated into cast iron. After annealing, the blocky pearlite is transformed into granular pearlite, which changes the microstructure of the glass mold and thus improves the hardness of the glass mold. At the same time, it gives the glass mold excellent oxidation and corrosion resistance, ensuring the quality of the glass mold and increasing its service life. 2. This application uses both inoculant and inoculant block simultaneously. The two work from different angles and have a good synergistic effect, which together improves the inoculation effect on cast iron, thereby improving the performance of cast iron glass molds. 3. This application transforms the microstructure of nickel-added cast iron glass mold from blocky pearlite to granular pearlite through a simple annealing process. The method is simple, highly operable, and improves the hardness of the cast iron glass mold, making it less prone to cracking. Detailed Implementation

[0025] The present application will be further described in detail below through examples. Example

[0026] Example 1 This embodiment discloses a nickel-alloyed cast iron glass mold comprising the following raw materials: 3.50 wt% C, 1.70 wt% Si, 0.50 wt% Mn, 1.00 wt% Ni, 0.36 wt% Cr, 0.36 wt% Mo, 0.08 wt% S, 0.30 wt% P, 0.05 wt% V, 0.08 wt% Ti, 1.0 wt% Cu, and 91.07 wt% Fe (containing unavoidable impurities).

[0027] This embodiment also discloses a method for preparing a nickel alloy cast iron glass mold, including the following steps: S1, Ingredients: Pig iron, scrap steel, recycled materials, ferromanganese, ferrosilicon and ferronickel are used as raw materials; S2, Smelting: Place the above raw materials in a smelting furnace, heat to 1480℃, and control the smelting time to 2 minutes to obtain molten iron; S3, Inoculation: Add 3g of barium silicon inoculant to the ladle, then pour the above 1000g of molten iron into the ladle. The inoculation temperature is 1430℃, and the inoculation time is 2 minutes. S4, Casting: Place 20g of inoculation block into the mold cavity, then pour the molten iron after the above inoculation into the mold. The molten iron cools to obtain a blank. Control the casting temperature to 1370℃. S5, Annealing: After removing the obtained blank from the mold, place it in an annealing furnace and heat it to 953°C, then hold it at that temperature for 10 hours; after annealing, cool the blank with the furnace to 500°C, then remove it from the furnace and air cool it to room temperature to obtain a nickel-alloy cast iron glass mold with D-type graphite in the inner cavity, 5% granular pearlite content, and A / D graphite in the core part, 20% granular pearlite content.

[0028] Example 2 This embodiment is basically the same as Embodiment 1, except that: this embodiment discloses a nickel alloy cast iron glass mold, comprising the following raw materials: C 3.65wt%, Si 1.85wt%, Mn 0.70wt%, Ni 1.30%, Cr 0.60%, Mo 0.50wt%, S 0.05wt%, P 0.20wt%, V 0.04wt%, Ti 0.06wt%, Cu 0.8wt%, and Fe (containing unavoidable impurities) 90.25wt%.

[0029] Example 3 This embodiment is basically the same as Embodiment 1, except that the preparation method of the nickel alloy cast iron glass mold disclosed in this embodiment includes the following steps: S1, Ingredients: Pig iron, scrap steel, recycled materials, ferromanganese, ferrosilicon and ferronickel are used as raw materials; S2, Smelting: Place the above raw materials in a smelting furnace, heat to 1505℃, and control the smelting time to 2 minutes to obtain molten iron; S3, Inoculation: Add 4g of barium silicon inoculant to the ladle, then pour the above 1000g of molten iron into the ladle. The inoculation temperature is 1440℃, and the inoculation time is 2 minutes. S4, Casting: Place 25g of inoculation block into the mold cavity, then pour the molten iron after the above inoculation into the mold. The molten iron cools to obtain a blank. Control the casting temperature to 1375℃. S5, Annealing: After removing the obtained blank from the mold, place it in an annealing furnace and heat it to 955℃, then hold it at that temperature for 10 hours; after annealing, cool the blank with the furnace to 500℃, then remove it from the furnace and air cool it to room temperature to obtain a nickel-alloy cast iron glass mold with D-type graphite in the inner cavity, 5% granular pearlite content, and A / D graphite in the core part, 20% granular pearlite content.

[0030] Example 4 This embodiment is basically the same as Embodiment 1, except that the preparation method of the nickel alloy cast iron glass mold disclosed in this embodiment includes the following steps: S1, Ingredients: Pig iron, scrap steel, recycled materials, ferromanganese, ferrosilicon and ferronickel are used as raw materials; S2, Smelting: Place the above raw materials in a smelting furnace, heat to 1530℃, and control the smelting time to 2 minutes to obtain molten iron; S3, Inoculation: Add 5g of barium silicon inoculant to the ladle, then pour the above 1000g of molten iron into the ladle. The inoculation temperature is 1450℃, and the inoculation time is 2 minutes. S4, Casting: Place 30g of inoculation block into the mold cavity, then pour the molten iron after the above inoculation into the mold. The molten iron cools to obtain a blank. Control the casting temperature to 1380℃. S5, Annealing: After removing the obtained blank from the mold, place it in an annealing furnace and heat it to 957°C, then hold it at that temperature for 10 hours; after annealing, cool the blank with the furnace to 500°C, then remove it from the furnace and air cool it to room temperature to obtain a nickel-alloy cast iron glass mold with D-type graphite in the inner cavity, 5% granular pearlite content, and A / D graphite in the core part, 20% granular pearlite content.

[0031] Comparative Example Comparative Example 1 The difference between this comparative example and Example 1 is that the nickel-alloy cast iron glass mold disclosed in this comparative example comprises the following raw materials: C 3.50 wt%, Si 1.70 wt%, Mn 0.50 wt%, Ni 0.1%, Cr 0.36%, Mo 0.36 wt%, S 0.08 wt%, P 0.30 wt%, V 0.05 wt%, Ti 0.08 wt%, Cu 1.0 wt%, and Fe (containing unavoidable impurities) 91.97 wt%.

[0032] Comparative Example 2 The difference between this comparative example and Example 1 is that the nickel-alloy cast iron glass mold disclosed in this comparative example comprises the following raw materials: C 3.50 wt%, Si 1.70 wt%, Mn 0.50 wt%, Ni 0.2%, Cr 0.36%, Mo 0.36 wt%, S 0.08 wt%, P 0.30 wt%, V 0.05 wt%, Ti 0.08 wt%, Cu 1.0 wt%, and Fe (containing unavoidable impurities) 91.87 wt%.

[0033] Comparative Example 3 The difference between this comparative example and Example 1 is that the nickel-alloy cast iron glass mold disclosed in this comparative example comprises the following raw materials: C 3.50 wt%, Si 1.70 wt%, Mn 0.50 wt%, Ni 2%, Cr 0.36%, Mo 0.36 wt%, S 0.08 wt%, P 0.30 wt%, V 0.05 wt%, Ti 0.08 wt%, Cu 1.0 wt%, and Fe (containing unavoidable impurities) 89.97 wt%.

[0034] Performance testing 1. Hardness test: The nickel-alloy cast iron glass molds obtained in Examples 1-4 and Comparative Examples 1-3 were tested for Brinell hardness according to the test method of GB / T231-2018, wherein the diameter of the cemented carbide ball was 10 mm and the test force was 29420 N; the test results are recorded in Table 1.

[0035] Table 1 Performance test data of Examples 1-4 and Comparative Examples 1-3 Referring to Table 1, and in conjunction with Examples 1-4 and Comparative Examples 1-3, it can be seen that increasing the nickel content in the cast iron glass mold within an appropriate range significantly improves the Brinell hardness of the resulting glass mold. This is because nickel can form high-strength alloys with copper, iron, etc. These alloys eventually enter the cast iron, and after annealing, the massive pearlite transforms into granular pearlite, altering the microstructure of the glass mold and thus increasing its hardness. Simultaneously, this gives the glass mold excellent resistance to oxidation and corrosion, ensuring its quality and increasing its service life. However, if the nickel content in the glass mold is too high, although its Brinell hardness increases significantly, it also increases the brittleness of the cast iron alloy, making it prone to cracking, thus resulting in a relatively shorter service life.

[0036] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a nickel alloy cast iron glass mold, characterized in that: It is prepared according to the following raw material ratio: C: 3.50-3.65wt%, Si: 1.70-1.85wt%, Mn: 0.50-0.70wt%, Ni: 1.00-1.30%, Cr: 0.36-0.60%, Mo: 0.36-0.50wt%, S≤0.08wt%, P≤0.30wt%, V≤0.05wt%, Ti≤0.08wt%, Cu≤1.0wt%, with the remainder being Fe and unavoidable impurities; Preparation method Includes the following steps: Ingredients: Prepare appropriate quantities of pig iron, scrap steel, recycled materials, ferromanganese, ferrosilicon, and ferronickel as raw materials according to the proportions of each element; Smelting: The raw materials are placed in a smelting furnace and melted to obtain molten iron; Inoculation: Inoculating agent and molten iron are added to the ladle in sequence to obtain inoculated molten iron; Casting: Add an inoculating block into the mold cavity, and pour the inoculated molten iron into the mold. The molten iron cools to obtain a blank. Annealing: After the blank is removed from the mold, it is heated and kept at a certain temperature; after annealing, the blank is cooled in the furnace and then air-cooled to obtain a nickel alloy cast iron glass mold. The inner cavity of the nickel-alloyed cast iron glass mold is made of type D graphite with a pearlite content of 5%; the core part is made of type A / D graphite with a pearlite content of 20%. The inoculant used is barium silicon inoculant, and the amount of barium silicon inoculant added is 0.3-0.5 wt% of the molten iron. The amount of the inoculated block added is 2-3 wt% of the molten iron; During the incubation process, the incubation temperature is 1430-1450℃, and the incubation time is 2 minutes. During the pouring process, the pouring temperature is 1370-1380℃, and the pouring time is 5-10 minutes. The pearlite is granular pearlite; the inoculated block includes a cavity portion with a central depression at the top.

2. The method for preparing a nickel-alloy cast iron glass mold according to claim 1, characterized in that: The melting temperature during the smelting process is 1480-1530℃.

3. The method for preparing a nickel-alloy cast iron glass mold according to claim 1, characterized in that: During the annealing process, the blank is heated to 953-957℃ and held for 10 hours. After being cooled to 500℃ in the furnace, it is removed from the furnace and air-cooled to room temperature.

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