A cast iron material, a method for producing the same, and an application thereof

Abstract

The application discloses a cast iron material and a preparation method thereof, and belongs to the technical field of metal materials and casting. The application applies Yb, a heavy rare earth, to a cylinder sleeve cast iron inoculant for the first time through Cu-Mo-Sn-Cr-V-W six-element synergistic strengthening and combined La and Ce light rare earth and Yb heavy rare earth composite inoculation. The tensile strength of the cast iron material is greater than or equal to 380 MPa (gray cast iron) or greater than or equal to 700 MPa (nodular cast iron), the 450 DEG C strength retention rate is greater than or equal to 85%, the effective inoculation time is prolonged to 8-10 minutes, and the cast iron material is suitable for centrifugal casting or sand mold casting production of internal combustion engine cylinder sleeves and compressor cylinder sleeves.

Description

Technical Field

[0001] This application relates to the field of cast iron materials technology, and in particular to a cast iron material, its preparation method, and its application. Background Technology

[0002] The cylinder liner (or simply cylinder liner) is a core component of internal combustion engines (including automotive engines, marine diesel engines, and compressors). Together with the piston rings and piston, it forms the engine's working chamber, directly bearing the cyclical action of high-temperature, high-pressure combustion gases and the high-speed reciprocating friction of the piston rings. Its working environment is extremely harsh, specifically: the combustion pressure of modern automotive diesel engines can reach 20-25 MPa, and high-performance engines (such as heavy-duty diesel engines and marine engines) can even reach 25-30 MPa; the combustion chamber temperature can reach over 2000℃, while the working temperature of the cylinder liner inner wall is typically between 200-400℃; the reciprocating speed of the piston rings can reach 10-15 m / s, and they are constantly under boundary lubrication. Therefore, the cylinder liner material must meet multiple requirements, including high strength, fatigue resistance, high temperature resistance, high wear resistance, and good processability.

[0003] Tensile strength is one of the most important mechanical properties of cast iron materials used in cylinder liners, directly affecting the structural safety and service life of the cylinder liner. Current technologies generally use alloying methods to improve the tensile strength of cast iron materials. While increasing alloying elements (Cr, Mo) and reducing the carbon equivalent can improve tensile strength, it reduces thermal conductivity, which is particularly detrimental to hot-load components such as brake discs and cylinder liners. Traditional inoculants (such as 75% ferrosilicon and single rare-earth ferrosilicon) have poor anti-fading capabilities, with an effective inoculation time of only 3-5 minutes, making them difficult to adapt to ladle casting processes, and resulting in unstable graphite morphology control. Summary of the Invention

[0004] To solve or partially solve the problems existing in the related technologies, this application provides a cast iron material, its preparation method and application, wherein the cast iron material achieves a tensile strength ≥380 MPa in gray cast iron cylinder liners.

[0005] This invention provides a cast iron material comprising the following chemical composition by weight percentage: C 3.0%-3.6%, Si 1.8%-2.6%, Mn 0.6%-1.0%, P ≤0.08%, S 0.06%-0.12%, Cr 0.25%-0.50%, Cu 0.4%-0.8%, Mo 0.25%-0.50%, Sn 0.03%-0.10%, V ≤0.15%, Ti ≤0.04%, W ≤0.02%; balance Fe and unavoidable impurities. The preparation method of cast iron material adopts a composite inoculant; the composite inoculant includes the following chemical composition by mass percentage: La 0.5%-3.0%, Ce 0.5%-3.0%, Yb 0.1%-1.5%, Ba 2.0%-8.0%, Si 40%-60%, with the balance being Fe and unavoidable impurities.

[0006] Optionally, the cast iron material comprises the following chemical composition by mass percentage: C 3.3%-3.5%, Si 2.0%-2.4%, Mn 0.7%-0.9%, P ≤0.05%, S 0.08%-0.10%, Cr 0.30%-0.45%, Cu 0.5%-0.7%, Mo 0.30%-0.45%, Sn 0.04%-0.08%, V 0.08%-0.12%, Ti 0.01%-0.03%, W 0.005%-0.015%, with the balance being Fe and unavoidable impurities.

[0007] Optionally, the compound inoculant comprises the following chemical components by weight percentage: La 1.0%-2.0%, Ce 1.0%-2.0%, Yb 0.3%-0.8%, Ba 4.0%-6.0%, Si 48%-55%, with the balance being Fe and unavoidable impurities.

[0008] Optionally, the preparation method of the compound progesterone is as follows: La, Ce, Yb, Ba, and Si are heated to 1480℃ and melted. After complete melting, the mixture is stirred evenly and cast into ingots. After the ingots cool, they are crushed and then screened: particles with a diameter of 5-15 mm are used for pre-inoculation in the ladle, and particles with a diameter of 2-6 mm are used for in-flow inoculation.

[0009] This invention also provides a method for preparing cast iron material, comprising the following steps: (1) Batching: Weigh the furnace charge according to the mass fraction of claim 1; (2) Smelting: The furnace charge is melted, heated, and held at the temperature before being subjected to overheating treatment; (3) Composition adjustment: Sampling and analyzing chemical composition to adjust final sulfur content; (4) Inoculation treatment: Cool the molten iron and add a compound inoculator; (5) Casting: The molten iron after inoculation treatment is cast into shape.

[0010] Optionally, in step (2), the heating temperature is 1520-1550℃ and the holding time is 10-15 minutes.

[0011] Optionally, the final sulfur content can be adjusted to 0.08%-0.10%.

[0012] Optionally, the molten iron is cooled to 1430-1480℃; the amount of composite inoculant added is 0.5%-1.2% of the mass of the molten iron.

[0013] The present invention also provides the application of the above-mentioned cast iron material in the preparation of internal combustion engine cylinder liners or compressor cylinder liners.

[0014] The technical solution provided in this application may include the following beneficial effects: (1) This invention achieves a tensile strength of ≥380 MPa in gray cast iron cylinder liners through the synergistic strengthening of six elements: Cu-Mo-Sn-Cr-VW, which is more than 30% higher than that of conventional cast iron cylinder liners (280-320 MPa); and a tensile strength of ≥700 MPa in ductile iron cylinder liners.

[0015] (2) This invention utilizes a composite inoculation process of light and heavy rare earth elements (La, Ce, Yb) combined with active sulfur control (S 0.08%-0.10%) to form rare earth sulfide nucleation cores, thereby controlling the hardness fluctuation of the cylinder liner within ±10 HB, which is significantly better than that of conventional cylinder liners. The substantial improvement in hardness uniformity is beneficial for subsequent precision machining and reduces uneven wear during use.

[0016] (3) The technical solution of the present invention is applicable to both gray cast iron and ductile iron cylinder liners, and is suitable for centrifugal casting and sand casting processes. It can obtain excellent microstructure uniformity and mechanical properties for cylinder liners with wall thickness of 8-20mm, and has good prospects for industrial promotion and application.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0018] These embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0019] Example 1 Example 1 provides a method for preparing cast iron material, comprising the following steps: (1) Ingredients Weigh the following furnace charge per ton of molten iron: Q10 pig iron: 450 kg Low-carbon scrap steel: 350 kg 200 kg of recycled material of the same type Graphitized carbide: appropriate amount 75% Ferrosilicon (FeSi75): 15 kg Ferromanganese (FeMn65): 8 kg Ferrochrome (FeCr65): 5 kg Electrolytic copper (Cu≥99.5%): 6 kg Ferromolybdenum (FeMo60): 4 kg Tin granules (Sn≥99%): 0.6 kg Ferrovanadium (FeV50): 1.5 kg Iron titanium (FeTi30): 0.5 kg Ferrotungsten (FeW70): 0.2 kg Iron sulfide (FeS): Appropriate amount Target chemical composition: C 3.6%, Si 2.2%, Mn 0.6%, P 0.05%, S 0.09%, Cr 0.25%, Cu 0.6%, Mo 0.50%, Sn 0.06%, V 0.15%, Ti 0.02%, W 0.01%, with the balance being Fe and unavoidable impurities.

[0020] (2) Smelting Weighed pig iron, scrap steel, and recycled materials are added to the medium-frequency induction furnace, and the power is turned on to heat and melt them. After all the materials have melted, the temperature is raised to 1450℃, and the carburizing agent is added in batches, holding for 5 minutes to allow the carburizing agent to fully dissolve and be absorbed. Then, ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, ferrotitanium, and ferrotungsten are added in sequence, and the temperature is raised to 1480℃, stirring to ensure that the alloying elements are evenly dissolved. Finally, electrolytic copper and tin granules are added, and the temperature is further raised to 1540℃, holding for 10 minutes for overheating treatment to purify the molten iron and eliminate the inherited defects of the materials.

[0021] After heat treatment, the pre-furnace sample was analyzed for chemical composition using a direct-reading spectrometer. Based on the analysis results, the sulfur content was adjusted to 0.09%.

[0022] After the adjustment is completed, turn off the power and allow the molten iron to cool naturally to 1460℃ (inoculation temperature) in preparation for tapping.

[0023] (3) Preparation of compound progesterone A mixture of 3.0% La, 1.5% Ce, 0.1% Yb, 5.0% Ba, 50% Si, and the balance iron was added to a medium-frequency induction furnace and heated to 1480℃ for melting. After complete melting, the mixture was stirred evenly and cast into ingots. After cooling, the ingots were crushed using a jaw crusher and then sieved using a vibrating screen: particles with a diameter of 5-15mm were used for pre-inoculation in the ladle, and particles with a diameter of 2-6mm were used for in-flow inoculation. The sieved inoculant was then stored in a moisture-proof sealed bag for later use.

[0024] (4) Pregnancy treatment Pre-inoculating particles (5-15mm), accounting for 40% of the total inoculant, are added to the bottom of the ladle. Then, the molten iron obtained in step (2) at 1460℃ is poured into the ladle, and the inoculant is fully melted by the impact force of the molten iron. During tapping, inoculating particles (2-6mm), accounting for 60% of the total inoculant, are added evenly with the iron flow. The total amount of inoculant added is 0.8% of the mass of the molten iron. After tapping, the molten iron is manually stirred for 10-15 seconds to ensure that the inoculant is evenly distributed.

[0025] After inoculation, the molten iron should be poured within 8 minutes to take advantage of the anti-fading window provided by the Yb element.

[0026] (5) Centrifugal casting Preheat the centrifugal casting mold to 200℃, uniformly spray water-based zircon powder coating with a thickness of 0.3-0.5mm, and dry with hot air. Start the centrifuge and increase the speed to 1200 rpm (adjust according to the cylinder liner diameter). Pour the inoculated molten iron obtained in step (4) into the mold in a measured amount at a pouring temperature of 1390℃ and a pouring time of less than 8 seconds. Keep the mold rotating for about 60 seconds, and stop the machine after the molten iron has completely solidified. Remove the casting. The casting temperature at the time of removal from the mold is about 850℃.

[0027] (6) Cooling and cleaning After removal, the cylinder liner casting is allowed to cool naturally to room temperature in the air. Once cooled, the gate and riser are removed using a hydraulic hammer, and then the outer diameter is rough-turned on a horizontal lathe to remove the mold contact layer (approximately 1.5 mm of turning material per side). A visual inspection is performed after rough turning to confirm the absence of casting defects such as cracks, porosity, and shrinkage cavities.

[0028] (7) Performance testing Samples were taken from single-cast test bars from the same heat and subjected to the following tests: Tensile strength test: Tensile test was performed using a universal testing machine in accordance with GB / T 228.1 standard, and the tensile strength was measured to be 385 MPa.

[0029] Hardness test: Three points were evenly selected on the inner wall of the cylinder liner and tested using a Brinell hardness tester (indenter diameter 10mm, load 3000kg, holding time 10 seconds). The measured hardness values ​​were 242 HB, 238 HB, and 245 HB, with an average hardness of 242 HB and a hardness fluctuation of 7 HB for the same part.

[0030] Metallographic examination: A metallographic sample was cut at 1 / 2 of the cylinder liner wall thickness, etched with 4% nitric acid alcohol, and observed under an optical microscope (100×). The results showed that the graphite morphology was type A graphite, with uniform graphite distribution; the matrix structure was pearlite, with a pearlite content of 90%. There were no pinhole defects caused by aluminum.

[0031] High-temperature strength retention rate test: According to GB / T 228.2 standard, a high-temperature tensile test was conducted at 450℃. The tensile strength at 450℃ was measured to be 339 MPa, and the tensile strength at room temperature was 385 MPa. The strength retention rate at 450℃ was calculated to be 88%.

[0032] (8) Conclusion The gray cast iron cylinder liner prepared in this embodiment has a tensile strength of 385 MPa, a hardness of 242±7 HB, and a strength retention rate of 88% at 450℃. Its comprehensive performance meets the requirements for use in high-strength engine cylinder liners.

[0033] Example 2 This embodiment provides a method for preparing cast iron material, the specific steps of which are as follows: (1) Ingredients Weigh the following furnace charge per ton of molten iron: Q10 pig iron: 500 kg Low-carbon scrap steel: 350 kg Ductile iron remelting material: 150 kg Graphitized carbide: appropriate amount 75% ferrosilicon: 18 kg Ferromanganese: 7 kg Ferrochrome: 4 kg Electrolytic copper: 6.5 kg Ferromolybdenum: 5 kg Tin granules: 0.5 kg Ferrovanadium: 1.3 kg Titanium iron: 0.5 kg Ferrotungsten: 0.15 kg Spheroidizing agent (FeSiMg6RE2): 12 kg Iron sulfide: appropriate amount Target chemical composition: In this embodiment, the specific values ​​are: C 3.0%, Si 2.4%, Mn 1.0%, P 0.08%, S 0.085%, Cr 0.50%, Cu 0.65%, Mo 0.25%, Sn 0.10%, V 0.05%, Ti 0.04%, W 0.02%, with the balance being Fe and unavoidable impurities.

[0034] (2) Smelting and spheroidizing treatment The smelting process was the same as in Example 1, with the temperature superheated to 1540°C and held for 10 minutes, and the sulfur content adjusted to 0.085%.

[0035] Before tapping, the spheroidizing agent (FeSiMg6RE2) is placed in the recess at the bottom of the ladle and covered and compacted with silicon steel sheets. The tapping temperature is 1480℃, and spheroidization is performed using the pouring method. The reaction is vigorous after the molten iron is poured in, so stirring is maintained. After spheroidization, the slag is skimmed off 2-3 times to remove the slag produced by the spheroidization reaction.

[0036] (3) Preparation of compound progesterone The specific values ​​of the inoculant in this embodiment are: La 0.5%, Ce 3.0%, Yb 1.5%, Ba 8.0%, Si 60%, and the balance is iron.

[0037] The preparation method is the same as in Example 1.

[0038] (4) Pregnancy treatment The process employs a combination of in-lamb inoculation and in-flow inoculation: After spheroidization, 40% of the total inoculant volume (5-15mm) is added to the ladle, and stirred to ensure uniform distribution. During the tapping process to the casting ladle, 60% of the total inoculant volume (2-6mm) is added evenly with the molten iron. The total inoculant volume is 1.0% of the molten iron mass. The molten iron should be poured within 10 minutes after the inoculation treatment.

[0039] (5) Centrifugal casting The pouring temperature was 1400℃, the casting speed was 1300 rpm, and the other parameters were the same as in Example 1.

[0040] (6) Cooling, cleaning and inspection Cooling and cleaning are the same as in Example 1.

[0041] Performance test results: tensile strength 730 MPa, hardness 265 HB, spheroidization rate 88%, pearlite content 90%, strength retention rate at 450℃ 90%, and no pinhole or porosity defects in the casting.

[0042] (7) Conclusion The ductile iron cylinder liner prepared in this embodiment has a tensile strength of 730 MPa and a spheroidization rate of 88%, and its comprehensive performance meets the requirements for use in high-strength engine cylinder liners.

[0043] Example 3 This embodiment provides a method for preparing cast iron material, the specific steps of which are as follows: (1) Ingredients Target chemical composition: In this embodiment, the specific values ​​are: C 3.3%, Si 1.8%, Mn 0.8%, P 0.06%, S 0.12%, Cr 0.35%, Cu 0.8%, Mo 0.35%, Sn 0.03%, V 0.10%, Ti 0.01%, W 0.005%, with the balance being Fe and unavoidable impurities.

[0044] (2) Smelting The smelting process is the same as in Example 1, with superheating to 1530°C and adjusting the sulfur content to 0.12%. After adjustment, the molten iron is allowed to cool naturally to 1450°C in preparation for tapping.

[0045] (3) Preparation of compound progesterone The specific values ​​of the inoculant in this embodiment are: La 1.0%, Ce 0.5%, Yb 0.3%, Ba 2.0%, Si 45%, and the balance is iron.

[0046] The preparation method is the same as in Example 1.

[0047] (4) Pregnancy treatment The total amount of inoculant added was 0.9% of the mass of molten iron. The process of pre-inoculation in the ladle plus in-flow inoculation was adopted, in the same manner as in Example 1.

[0048] (5) Centrifugal casting The pouring temperature was 1380℃, and the other parameters were the same as in Example 1.

[0049] (6) Performance testing The tensile strength is 378 MPa, the hardness is 240 HB, the strength retention rate at 450℃ is 87%, the graphite morphology is type A (85%), the pearlite content is 91%, and the casting is free of pinholes and porosity defects.

[0050] (7) Conclusion The cast iron material prepared in this embodiment has a tensile strength of 378 MPa, a hardness of 240 HB, and a strength retention rate of 87% at 450℃, exhibiting good overall performance.

[0051] Example 4 This embodiment provides a method for preparing cast iron material, the specific steps of which are as follows: (1) Ingredients Target chemical composition: In this embodiment, the specific values ​​are: C 3.2%, Si 2.6%, Mn 0.7%, P 0.04%, S 0.06%, Cr 0.40%, Cu 0.4%, Mo 0.40%, Sn 0.08%, V 0.12%, Ti 0.03%, W 0.015%, with the balance being Fe and unavoidable impurities.

[0052] (2) Smelting The smelting process is the same as in Example 1, with superheating to 1520°C and adjusting the sulfur content to 0.06%. After adjustment, the molten iron is allowed to cool naturally to 1470°C in preparation for tapping.

[0053] (3) Preparation of compound progesterone The specific values ​​of the inoculant in this embodiment are: La 2.5%, Ce 2.0%, Yb 0.6%, Ba 6.5%, Si 55%, and the balance is iron.

[0054] The preparation method is the same as in Example 1.

[0055] (4) Pregnancy treatment The total amount of inoculant added is 1.0% of the mass of molten iron. The process of pre-inoculation in the ladle plus in-flow inoculation is the same as in Example 1.

[0056] (5) Centrifugal casting The pouring temperature was 1410℃, and the other parameters were the same as in Example 1.

[0057] (6) Performance testing The tensile strength is 390 MPa, the hardness is 248 HB, the strength retention rate at 450℃ is 89%, the graphite morphology is type A (87%), the pearlite content is 93%, and the casting is free of pinholes and porosity defects.

[0058] (7) Conclusion The cast iron material prepared in this embodiment has a tensile strength of 390 MPa, a hardness of 248 HB, and a strength retention rate of 89% at 450℃, exhibiting excellent comprehensive performance.

[0059] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in step (1), the ingredients are 0.15% Cr, 0.2% Cu, 0.15% Mo, and 0.01% Sn, while other conditions remain unchanged.

[0060] Performance testing: tensile strength 312 MPa, hardness 210 HB, strength retention rate at 450℃ 72%, graphite morphology is type A (75%), pearlite content 78%, castings are free of pinholes and porosity defects.

[0061] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that Yb is not added to the compound inoculant in step (3), while other conditions remain unchanged.

[0062] Performance testing: tensile strength 358 MPa, hardness 232 HB, strength retention rate at 450℃ 80%, graphite morphology is type A (82%), but a small amount of supercooled graphite appeared 8 minutes after inoculation, effective inoculation time is about 5 minutes, pearlite content is 85%, and the casting has no pinhole or porosity defects.

[0063] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that La and Ce are not added to the composite inoculant in step (3) (only Yb is retained), while other conditions remain unchanged.

[0064] Performance testing: tensile strength 348 MPa, hardness 225 HB, strength retention rate at 450℃ 76%, graphite morphology is type A (70%), with a large amount of supercooled graphite, pearlite content 80%, and no pinhole or porosity defects in the casting.

[0065] Comparative Example 4 The difference between Comparative Example 3 and Example 1 is that the ratio of the composite inoculant La-Ce-Yb in step (3) is 0.2% La, 0.2% Ce, and 2.0% Yb, while other conditions remain unchanged.

[0066] Performance testing: tensile strength 352 MPa, hardness 250 HB, strength retention rate at 450℃ 78%, graphite morphology is type A (72%), but there are signs of excessive rare earth elements (graphite coarsening, local carbides), pearlite content 82%, and the casting has no pinhole or porosity defects.

[0067] Comparative Example 1, with altered Cr, Cu, Mo, and Sn contents, exhibited a tensile strength of only 312 MPa, a strength retention rate of only 72% at 450℃, and a pearlite content of only 78%, resulting in significantly lower overall performance compared to Example 1.

[0068] Comparative Example 2, due to the absence of Yb in the inoculant, exhibited a tensile strength of 358 MPa, which was lower than that of Example 1 (392 MPa). The strength retention rate at 450°C was 80%, which was also lower than that of Example 1 (89%). The effective inoculum time was only 5 minutes, significantly shorter than the 8 minutes of Example 1, indicating a significantly insufficient resistance to degradation.

[0069] Comparative Example 3, due to the absence of La and Ce (light rare earth elements) in the inoculant and the reliance solely on Yb (heavy rare earth elements), exhibited a tensile strength of 348 MPa, which was lower than that of Example 1 (392 MPa). The graphite morphology deteriorated, with an increase in supercooled graphite and a pearlite content of only 80%, resulting in a significant decrease in overall performance.

[0070] Comparative Example 4 altered the contents of La, Ce, and Yb, resulting in an imbalance in the ratio of light to heavy rare earth elements. The tensile strength of 352 MPa was lower than that of Example 1 (392 MPa). The graphite morphology deteriorated, with graphite coarsening and carbides appearing due to excessive rare earth elements, leading to a decline in overall performance.

[0071] The range of chemical components and the range of probiotic components protected by this invention have a synergistic effect; exceeding or falling below the range will not achieve the expected comprehensive performance.

[0072] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A cast iron material, characterized in that, Includes the following chemical components by mass percentage: C 3.0%-3.6%, Si 1.8%-2.6%, Mn 0.6%-1.0%, P ≤0.08%, S 0.06%-0.12%, Cr 0.25%-0.50%, Cu 0.4%-0.8%, Mo 0.25%-0.50%, Sn 0.03%-0.10%, V ≤0.15%, Ti ≤0.04%, W ≤0.02%; balance Fe and unavoidable impurities. The method for preparing the cast iron material employs a composite inoculant; the composite inoculant comprises the following chemical components by mass percentage: La 0.5%-3.0%, Ce 0.5%-3.0%, Yb 0.1%-1.5%, Ba 2.0%-8.0%, Si 40%-60%, with the balance being Fe and unavoidable impurities.

2. The cast iron material according to claim 1, characterized in that, The chemical composition includes the following percentages by mass: C 3.3%-3.5%, Si 2.0%-2.4%, Mn 0.7%-0.9%, P ≤0.05%, S 0.08%-0.10%, Cr 0.30%-0.45%, Cu 0.5%-0.7%, Mo 0.30%-0.45%, Sn 0.04%-0.08%, V 0.08%-0.12%, Ti 0.01%-0.03%, W 0.005%-0.015%, with the balance being Fe and unavoidable impurities.

3. The cast iron material according to claim 1, characterized in that, The composite inoculant comprises the following chemical components by mass percentage: La 1.0%-2.0%, Ce 1.0%-2.0%, Yb 0.3%-0.8%, Ba 4.0%-6.0%, Si 48%-55%, with the balance being Fe and unavoidable impurities.

4. The cast iron material according to claim 1, characterized in that, The preparation method of the compound progesterone is as follows: La, Ce, Yb, Ba, and Si are heated to 1480℃ and melted. After complete melting, the mixture is stirred evenly and cast into ingots. After the ingots cool, they are crushed and then screened: particles with a diameter of 5-15 mm are used for pre-inoculation in the ladle, and particles with a diameter of 2-6 mm are used for in-flow inoculation.

5. A method for preparing cast iron material, characterized in that, Includes the following steps: (1) Batching: Weigh the furnace charge according to the mass fraction described in claim 1; (2) Smelting: The furnace charge is melted, heated, and held at the temperature before being subjected to overheating treatment; (3) Composition adjustment: Sampling and analyzing chemical composition to adjust final sulfur content; (4) Inoculation treatment: Cool the molten iron and add a compound inoculator; (5) Casting: The molten iron after inoculation treatment is cast into shape.

6. The method for preparing cast iron material according to claim 5, characterized in that, In step (2), the heating temperature is 1520-1550℃ and the holding time is 10-15 minutes.

7. The method for preparing cast iron material according to claim 5, characterized in that, The final sulfur content is adjusted to 0.08%-0.10%.

8. The method for preparing cast iron material according to claim 5, characterized in that, The molten iron is cooled to 1430-1480℃; the amount of composite inoculant added is 0.5%-1.2% of the mass of the molten iron.

9. The use of the cast iron material according to any one of claims 1-8 in the manufacture of internal combustion engine cylinder liners or compressor cylinder liners.