Cast iron glass mold with gradient graphite form change and preparation method of cast iron glass mold
By using cast iron materials with gradient graphite morphology in cast iron glass molds, using titanium element alienated spherical graphite, combined with wire feeding and secondary incubation treatment, the existing cast iron glass molds have been solved inadequate performance and shrinkage and shrinkage under high temperature conditions, and excellent high-temperature oxidation resistance and thermal conductivity are achieved, and the use performance of the mold is improved.
Patent Information
- Application Number
- CN202411989210.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-05-06
AI Technical Summary
Existing cast iron glass molds have problems with insufficient high-temperature oxidation resistance and high-temperature thermal conductivity under periodic high-temperature fluctuations, and common ductile cast iron glass molds are prone to shrinkage and shrinkage problems, which affects the mechanical processing and use performance.
Using cast iron material with gradient graphite morphology changes, through the alienation of titanium elements on spherical graphite, a gradient graphite morphology change from the glass contact surface to the outer circle direction is designed, and a transition zone to the spherical graphite to the worm-like graphite and the worm-like graphite region are successively formed. Combined with wire feeding and secondary fertilization treatment, cast iron glass molds with excellent performance are prepared.
The excellent oxidation resistance and thermal conductivity of cast iron glass molds under high temperature conditions are achieved, the problem of shrinkage and shrinkage is avoided, and the performance and practicality of the mold are improved.
Smart Images
Figure CN119932419A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of glass moulds, in particular to a cast iron glass mould with gradient graphite morphology change and a preparation method thereof. Background Art
[0002] Glass molds are limited by the use environment and performance requirements, and usually need to have good high-temperature oxidation resistance and high-temperature thermal conductivity. Traditional cast iron materials have many deficiencies in performance and are often difficult to meet both good high-temperature oxidation resistance and high-temperature thermal conductivity.
[0003] The existing glass mold manufacturing industry improves mold performance by adding a large amount of precious alloy elements, but this not only significantly increases costs and reduces market competitiveness, but also complicates the material casting production process and produces more pearlite. When glass molds are used under periodic high-temperature fluctuations, the pearlite matrix is an unstable phase, which has many disadvantages in practical applications. In addition, due to its solidification characteristics, common ductile iron glass mold blanks are prone to isolated liquid phase areas at the thickness steps of the casting wall, resulting in shrinkage cavities and shrinkage problems, which seriously affect subsequent machining and mold performance.
[0004] Therefore, there is an urgent need for a new type of cast iron material specifically for glass molds to overcome these defects. Summary of the invention
[0005] The present invention provides a cast iron glass mold with gradient graphite morphology change and a preparation method thereof, thereby solving the above-mentioned defects existing in the existing cast iron glass mold under the periodic high temperature fluctuation state during use.
[0006] In order to solve the above technical problems, the present invention provides a cast iron glass mold with gradient graphite morphology change, comprising the following components in percentage by mass:
[0007] Carbon 3.5-3.7%, silicon 2.5-2.8%, titanium 0.12-0.2%, manganese <0.2%, phosphorus <0.08%, sulfur <0.02%, magnesium 0.05-0.1%, and the rest are iron and other inevitable impurity elements.
[0008] In order to solve the above technical problems, the present invention provides a method for preparing a cast iron glass mold with a gradient graphite morphology change, comprising the following steps:
[0009] (1) Batching: According to the ratio of the above-mentioned various elements, accurately weigh the corresponding mass of silicon carbide, scrap steel, pig iron, recycled materials and ferrotitanium; the mass of the recycled materials is 20-30% of the total mass of the silicon carbide, scrap steel, pig iron and ferrotitanium;
[0010] (2) Melting and adjusting the silicon-carbon content: sequentially adding the silicon carbide, scrap steel and pig iron into a smelting furnace, and after all of them are melted, adding the recycled materials, using a silicon-carbon instrument to detect and adjust the carbon and silicon contents to within the formula range, and then adding ferrotitanium to melt to obtain molten iron;
[0011] (3) Wire feeding inoculation and wire feeding spheroidizing treatment: the furnace is opened to introduce the molten iron into the tundish, and then flows into the wire feeding spheroidizing station containing inoculated wire and spheroidizing wire for wire feeding inoculation and wire feeding spheroidizing treatment;
[0012] (4) Secondary inoculation: The molten iron flowing out of the wire feeding spheroidizing station is introduced into a transfer ladle, and then poured into a casting ladle containing an inoculant for secondary inoculation. After the inoculation is completed, the slag removal is completed on the slag removal platform;
[0013] (5) Casting: The molten iron after slag removal is poured into the molding cavity, and after cooling, it is unpacked and sorted, and graphitized and annealed to obtain the cast iron glass mold with gradient graphite morphology change.
[0014] In a preferred embodiment of the present invention, in step (3), the amount of the inoculated wire is 0.6% of the mass of the molten iron.
[0015] In a preferred embodiment of the present invention, the inoculated silk comprises the following formula components: Si 70-75%, Ca 1-3%, Ba 2-4%, Al≤1.5%, and the balance is Fe.
[0016] In a preferred embodiment of the present invention, in step (3), the amount of the spheroidized wire is 0.8% of the mass of the molten iron.
[0017] In a preferred embodiment of the present invention, the spheroidized yarn comprises the following formula components: Mg 17-24%, Re 2-4%, Si 40-45%, Ca 2-4%, Al≤1.2%, and the balance is Fe.
[0018] In a preferred embodiment of the present invention, in step (4), the amount of the inoculant is 0.5% of the mass of the molten iron.
[0019] In a preferred embodiment of the present invention, the inoculant includes the following formula components: Si 68-75%, Ca 1-2%, Ba 4-6%, Al≤1.5%, and the balance is iron.
[0020] In a preferred embodiment of the present invention, the time from the molten iron entering the wire feeding spheroidizing station to the completion of pouring is within 6 minutes.
[0021] In a preferred embodiment of the present invention, in step (5), the pouring temperature is 1380-1280°C.
[0022] The beneficial effects of the present invention are as follows: the present invention provides a cast iron glass mold with a gradient graphite morphology change and a preparation method thereof. By designing the formula components and utilizing the alienation effect of titanium element on spherical graphite, a cast iron glass mold with a gradient graphite morphology change from the glass contact surface to the outer circle direction, which is a spherical graphite zone, a spherical graphite to worm-like graphite transition zone and a worm-like graphite zone in sequence, is successfully prepared. The preparation process is simple and practical, and the cast iron glass mold prepared by the present invention has both excellent high-temperature oxidation resistance and high-temperature thermal conductivity, excellent performance and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of the process of a method for preparing a cast iron glass mold with gradient graphite morphology change according to the present invention. DETAILED DESCRIPTION
[0024] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.
[0025] Embodiments of the present invention include:
[0026] Example 1
[0027] The invention discloses a cast iron glass mold with a gradient graphite morphology change, comprising the following components: carbon, silicon, titanium, manganese, phosphorus, sulfur, magnesium, iron and other inevitable impurity elements. The specific mass of each element is shown in Table 1.
[0028] The method for preparing the cast iron glass mold specifically comprises the following steps:
[0029] (1) Batching: According to the proportions of various elements in Table 1, accurately weigh corresponding masses of silicon carbide, scrap steel, pig iron, recycled materials and ferrotitanium; the mass of the recycled materials is 20% of the total mass of the silicon carbide, scrap steel, pig iron and ferrotitanium;
[0030] (2) Melting and regulating silicon-carbon content: The silicon carbide, scrap steel and pig iron are sequentially added into a smelting furnace. After all of them are melted, the recycled materials are added. When the temperature of the molten iron reaches 1450° C., the carbon and silicon contents are detected and regulated to the amounts shown in Table 1 using a silicon-carbon instrument. The temperature is then raised to 1540° C., and ferrotitanium is added and kept warm for 5 min to allow the ferrotitanium to fully melt, thereby obtaining molten iron.
[0031] (3) Wire feeding inoculation and wire feeding spheroidizing treatment: the smelting furnace is opened, the molten iron is introduced into the tundish, and then flows into the wire feeding spheroidizing station containing the inoculated wire and the spheroidizing wire, and the wire feeding inoculation and wire feeding spheroidizing treatment are performed;
[0032] Specifically, the amount of the inoculated wire is 0.6% of the mass of the molten iron. The inoculated wire comprises the following formula components: Si 73%, Ca 2%, Ba 3%, Al≤1.5%, and the balance is Fe.
[0033] The amount of the spheroidized wire is 0.8% of the mass of the molten iron.
[0034] The spheroidized yarn comprises the following formula components: Mg 20%, Re 3%, Si 42%, Ca 3%, Al≤1.2%, and the balance is Fe.
[0035] (4) Secondary inoculation: The molten iron flowing out of the wire feeding spheroidizing station is introduced into a transfer ladle, and then poured into a casting ladle containing an inoculant for secondary inoculation. After the inoculation is completed, the slag removal is completed on the slag removal platform;
[0036] Specifically, the amount of the inoculant is 0.5% of the mass of the molten iron.
[0037] The inoculant comprises the following formula components: Si 70%, Ca 1%, Ba 5%, Al≤1.5%, and the balance is iron.
[0038] (5) Pouring: Adjust the initial pouring temperature of the molten iron after slag removal to 1380°C to ensure that the formed chill is not affected by high-temperature oxidation during the pouring process. Control the temperature at the end of pouring to be no less than 1280°C to avoid defects such as cold shut at the contact surface between the casting and the formed chill.
[0039] In addition, the total time from the flow of molten iron into the wire feeding spheroidizing station to the completion of pouring is controlled within 6 minutes to prevent spheroidization and inoculation decline.
[0040] (6) After the pouring is completed, the casting enters the static pressure line cooling channel, and when the casting temperature is lower than 320° C., the casting is unpacked and the sand is removed. The casting and the molding sand are separated by a box-poking machine to obtain a cast iron glass mold as-cast blank; then the casting and the riser are separated, shot blasted and sand removed, and the casting is placed in an annealing furnace for high-temperature graphitization annealing, cooled, unpacked and sorted to obtain the cast iron glass mold with gradient graphite morphology change.
[0041] In addition, the casting mold used in the above-mentioned pouring operation is prepared by the following method:
[0042] 1) Mix suitable molding sand to ensure that its water content is 3.5-4.5%, preferably 4.0%, compaction rate is 35-40%, preferably 38%, air permeability is 80-120mm / s, preferably 100mm / s, wet compressive strength is 90-130kPa, preferably 110kPa, and mud content is 8-14%, preferably 10%;
[0043] 2) Model making and assembly: Design the pouring system and make the wooden mold, and assemble it precisely according to the designed pouring system;
[0044] 3) Modeling and molding: Use a multi-contact static pressure line for molding. The hardness of the sand after molding is tested using a B-type molding sand hardness tester, and the parting surface hardness value is controlled to be ≥90; core is placed (using a specially designed molding chiller), and the static pressure line automatically closes the box to obtain a casting mold to be poured.
[0045] Among the above components, the alienation effect of titanium on spherical graphite makes the graphite morphology of the glass mold material of the present invention from the glass contact surface (the glass contact surface close to the forming cold iron) to the outer circle direction be distributed in the following order: spherical graphite area, transition area from spherical graphite to worm-like graphite, and worm-like graphite area close to the outer circle.
[0046] The cast iron glass mold prepared in this embodiment has no defects such as shrinkage cavities and shrinkage, and has stable performance during use, is not affected by high-temperature oxidation, has uniform thermal conductivity in different parts, has fast thermal conductivity, and has excellent high-temperature oxidation resistance and high-temperature thermal conductivity.
[0047] Example 2
[0048] A cast iron glass mold with gradient graphite morphology change, which is different from Example 1 in that the amounts of the components are different, as shown in Table 1.
[0049] The preparation method of the cast iron glass mold with gradient graphite morphology change is the same as that of Example 1.
[0050] The cast iron glass mold prepared in this embodiment has no defects such as shrinkage cavities and shrinkage, and has stable performance during use, is not affected by high-temperature oxidation, has uniform thermal conductivity in different parts, has fast thermal conductivity, and has excellent high-temperature oxidation resistance and high-temperature thermal conductivity.
[0051] Example 3
[0052] A cast iron glass mold with gradient graphite morphology change, which is different from Example 1 in that the amounts of the components are different, as shown in Table 1.
[0053] The cast iron glass mold prepared in this embodiment has no defects such as shrinkage cavities and shrinkage, and has stable performance during use, is not affected by high-temperature oxidation, has uniform thermal conductivity in different parts, has fast thermal conductivity, and has excellent high-temperature oxidation resistance and high-temperature thermal conductivity.
[0054] The preparation method of the cast iron glass mold with gradient graphite morphology change is the same as that of Example 1.
[0055] Table 1
[0056]
[0057] The cast iron glass mold with gradient graphite morphology changes prepared in the above Examples 1-3 has both excellent high-temperature oxidation resistance and high-temperature thermal conductivity. This is because spherical graphite is an isolated distributed graphite form, so the inner cavity oxidation resistance is much higher than that of worm-like graphite, and the graphite channels between the worm-like graphite eutectic clusters are connected, so the thermal conductivity is higher than that of spherical graphite.
[0058] The special cast iron material for glass molds with gradient graphite morphology changes of the present invention has both the excellent high-temperature oxidation resistance of ductile iron and the excellent high-temperature thermal conductivity of vermicular cast iron, which better reconciles the contradiction between the high-temperature oxidation resistance and high-temperature thermal conductivity of cast iron glass molds, and improves the performance of cast iron glass molds.
[0059] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A cast iron glass mold with gradient graphite morphology change, characterized in that: The following components are included in the mass percentage: Carbon 3.5-3.7%, silicon 2.5-2.8%, titanium 0.12-0.2%, manganese <0.2%, phosphorus <0.08%, sulfur <0.02%, magnesium 0.05-0.1%, and the rest are iron and other inevitable impurity elements.
2. A method for preparing a cast iron glass mold with a gradient graphite morphology change as claimed in claim 1, characterized in that: The steps include: (1) Batching: According to the ratio of the above-mentioned various elements, accurately weigh the corresponding mass of silicon carbide, scrap steel, pig iron, recycled materials and ferrotitanium; the mass of the recycled materials is 20-30% of the total mass of the silicon carbide, scrap steel, pig iron and ferrotitanium; (2) Melting and adjusting the silicon-carbon content: sequentially adding the silicon carbide, scrap steel and pig iron into a smelting furnace, and after all of them are melted, adding the recycled materials, using a silicon-carbon instrument to detect and adjust the carbon and silicon contents to within the formula range, and then adding ferrotitanium to melt to obtain molten iron; (3) Wire feeding inoculation and wire feeding spheroidizing treatment: the furnace is opened to introduce the molten iron into the tundish, and then flows into the wire feeding spheroidizing station containing inoculated wire and spheroidizing wire for wire feeding inoculation and wire feeding spheroidizing treatment; (4) Secondary inoculation: The molten iron flowing out of the wire feeding spheroidizing station is introduced into a transfer ladle, and then poured into a casting ladle containing an inoculant for secondary inoculation. After the inoculation is completed, the slag removal is completed on the slag removal platform; (5) Pouring: pouring the molten iron after slagging treatment into the molding cavity, cooling, unpacking and sorting, and graphitization annealing to obtain the cast iron glass mold with gradient graphite morphology change.
3. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 2, characterized in that: In step (3), the amount of the inoculated wire is 0.6% of the mass of the molten iron.
4. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 3, characterized in that: The inoculated silk comprises the following formula components: Si 70-75%, Ca 1-3%, Ba 2-4%, Al≤1.5%, and the balance is Fe.
5. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 2, characterized in that: In step (3), the amount of the spheroidized wire is 0.8% of the mass of the molten iron.
6. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 5, characterized in that: The spheroidized yarn comprises the following formula components: Mg 17-24%, Re 2-4%, Si 40-45%, Ca 2-4%, Al≤1.2%, and the balance is Fe.
7. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 2, characterized in that: In step (4), the amount of the inoculant is 0.5% of the mass of the molten iron.
8. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 7, characterized in that: The inoculant comprises the following formula components: Si 68-75%, Ca 1-2%, Ba4-6%, Al≤1.5%, and the balance is iron.
9. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 2, characterized in that: The time from the molten iron entering the wire feeding spheroidizing station to the completion of pouring is within 6 minutes.
10. The method for preparing a cast iron glass mold with a gradient graphite morphology change according to claim 2, characterized in that: In step (5), the pouring temperature is 1380-1280°C.