A compacted spheroidal graphite cast iron cylinder liner material and a method for producing the same
Patent Information
- Application Number
- CN202611003223.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-07
- Publication Date
- 2026-09-29
AI Technical Summary
[0016]（1）本发明所提供的技术方案中引入了Cu和Sb元素，其在灰铸铁气缸套材料中生成了极多的珠光体组织，且珠光体片层间距小致密性强，同时生成的石墨片细小且均匀分布，使气缸套的硬度，强度得到了极大提升。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of engine cylinder liner manufacturing technology, specifically relating to a dense pearlitic gray cast iron cylinder liner material and its preparation method. Background Technology
[0002] With the rapid development of the automotive industry, my country has become one of the world's largest automobile markets. In recent years, with the increasing prominence of energy, environmental, and transportation issues, my country has proposed a new development strategy for the automotive industry: "energy conservation and emission reduction." This necessitates higher fuel efficiency in our vehicles. The engine is considered the heart of a car, and the cylinder liner is one of its core components. The cylinder liner exists within the engine's rigid body, forming the combustion chamber along with the piston, piston rings, and cylinder head. During operation, it withstands high temperatures, high pressures, and significant friction. Therefore, cylinder liner products require extremely high quality to meet the demands of high-temperature, wear-resistant, and corrosion-resistant working conditions. Gray cast iron cylinder liners are among the most commonly used cylinder liners in automotive engines, characterized by low cost, high temperature resistance, and friction resistance. Currently, with the trend towards higher power and lighter weight in automobiles, the performance requirements for cylinder liners are becoming increasingly stringent. Developing a high-performance gray cast iron cylinder liner material to improve engine lifespan is of significant value. Summary of the Invention
[0003] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:
[0004] A dense pearlitic gray cast iron cylinder liner material, wherein the dense pearlitic gray cast iron cylinder liner material is composed of Fe, C, Si, Mn, P, S, Cu and Sb elements, with the chemical formula FeCSiMnPSCuSb, and each element is composed in the following weight percentages (wt.%): C 3.0%-3.4%, Si 1.8%-2.3%, Mn 0.3%-0.6%, P 0.13%-0.2%, S 0.04-0.08%, Cu 0.3-0.8%, Sb 0.02-0.04%, with the balance being Fe.
[0005] Preferably, the dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.02% Sb, with the balance being Fe.
[0006] Preferably, the dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.04% Sb, with the balance being Fe.
[0007] Preferably, the dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.6% Cu, 0.04% Sb, with the balance being Fe.
[0008] This invention also provides a method for preparing a dense pearlitic gray cast iron cylinder liner material, the preparation method specifically including the following steps:
[0009] Step 1: Mix and melt pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrisulfide powder, electrolytic copper, and ferroantimony according to the following weight percentages (wt.%): C: 3.0%-3.4%, Si: 1.8%-2.3%, Mn: 0.3%-0.6%, P: 0.13%-0.2%, S: 0.04-0.08%, Cu: 0.3-0.8%, Sb: 0.02-0.06%, with the balance being Fe.
[0010] Step 2: The centrifugal casting method is used for molding. The centrifugal speed during the centrifugal casting process is 1340-1500 rpm, the casting speed is 4.5-5.5 kg / s, and the casting temperature is 1420-1490℃.
[0011] Step 3: After centrifugal casting, a blank is obtained. The blank exits the mold at a temperature of 805-815℃, and the blank structure is in the austenitic state.
[0012] Step 4: After demolding, the blank is air-cooled at 535-585℃, then air-cooled to room temperature, and then annealed at 525-540℃ for 2-3.5 hours to obtain the cylinder liner material.
[0013] More preferably, in steps 2 and 3, the centrifugal speed during centrifugal casting is 1460 rpm, the casting speed is 5 kg / s, the casting temperature is 1440℃, and the blank exit temperature is 813℃.
[0014] In a further preferred embodiment, after the blank is removed from the mold in step 4, it is air-cooled to 560°C and then air-cooled to room temperature. Then, it is annealed in an annealing furnace at 535°C for 2.7 hours to finally obtain the cylinder liner material.
[0015] Compared with the prior art, the present invention has the following advantages:
[0016] (1) The technical solution provided by the present invention introduces Cu and Sb elements, which generate a large number of pearlite structures in gray cast iron cylinder liner materials. The pearlite lamellar spacing is small and the density is strong. At the same time, the generated graphite flakes are small and evenly distributed, which greatly improves the hardness and strength of the cylinder liner.
[0017] (2) There are no special restrictions on the centrifugal casting method in this invention. The centrifugal casting technology well known in the art can be used to prepare gray cast iron. Therefore, this solution is highly operable and repeatable.
[0018] (3) The present invention uses air cooling to cool the blank until the eutectoid transformation is complete, which can reduce the lamellar spacing between pearlite, and achieve the effect of refining the alloy structure in terms of process, thereby increasing the hardness and wear resistance of the material. Attached Figure Description
[0019] Figure 1 Pearlite tissue diagrams for comparison of Example 1, Example 2 and Example 3.
[0020] Figure 2 The Brinell hardness of Experimental Example 1, Experimental Example 2, Experimental Example 3 and Comparative Example 1.
[0021] Figure 3 The tensile strength of Experimental Example 1, Experimental Example 2, Experimental Example 3 and Comparative Example 1. Detailed Implementation
[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0023] This invention discloses a dense pearlitic gray cast iron cylinder liner material, which is composed of Fe, C, Si, Mn, P, S, Cu and Sb elements, with the chemical formula FeCSiMnPSCuSb. The elements are composed in the following weight percentages (wt.%): C 3.0%-3.4%, Si 1.8%-2.3%, Mn 0.3%-0.6%, P 0.13%-0.2%, S 0.04-0.08%, Cu 0.3-0.8%, Sb 0.02-0.04%, and the balance is Fe.
[0024] This invention also provides a method for preparing dense pearlitic gray cast iron cylinder liner material, which specifically includes the following steps:
[0025] Step 1: Mix and melt pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrosulfite powder, electrolytic copper, and ferroantimony according to the following weight percentages (wt.%): C: 3.0%-3.4%, Si: 1.8%-2.3%, Mn: 0.3%-0.6%, P: 0.13%-0.2%, S: 0.04-0.08%, Cu: 0.3-0.8%, Sb: 0.02-0.06%, with the balance being Fe. This invention does not impose any special restrictions on the types and sources of the above-mentioned raw materials (pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrosulfite powder, electrolytic copper, and ferroantimony). Those skilled in the art can mix the materials according to the above-mentioned component ratios to achieve the required content of each component in the gray cast iron cylinder liner described in the scheme.
[0026] Step 2: Centrifugal casting is performed using a vertical centrifugal casting machine. The centrifugal speed during the centrifugal casting process is 1340-1500 rpm, the casting speed is 4.5-5.5 kg / s, and the casting temperature is 1420-1490℃. Preferably, the centrifugal speed is 1460 rpm and the casting speed is 5 kg / s.
[0027] Step 3: After centrifugal casting, a blank is obtained. The blank exits the mold at a temperature of 805-815℃, and the blank structure is in the austenitic state. Preferably, the blank exits the mold at a temperature of 813℃.
[0028] Step 4: After demolding, the blank is air-cooled at 535-585℃ until it reaches room temperature. Then, the blank is annealed at 525-540℃ for 2-3.5 hours to obtain the cylinder liner material. Preferably, the blank is air-cooled to 560℃ and then air-cooled to room temperature. Then, it is annealed in an annealing furnace at 535℃ for 2.7 hours to obtain the cylinder liner material. Specific implementation method one:
[0030] This embodiment describes a dense pearlitic gray cast iron cylinder liner material composed of Fe, C, Si, Mn, P, S, Cu, and Sb elements, with the chemical formula FeCSiMnPSCuSb, and is composed of the following weight percentages (wt.%): C 3.0%-3.4%, Si 1.8%-2.3%, Mn 0.3%-0.6%, P 0.13%-0.2%, S 0.04-0.08%, Cu 0.3-0.8%, Sb 0.02-0.04%, with the balance being Fe. Specific Implementation Method Two:
[0032] In this embodiment, a dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.02% Sb, with the balance being Fe. Specific implementation method three:
[0034] In this embodiment, a dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.04% Sb, with the balance being Fe. Compared with specific embodiment two, this embodiment has a higher Sb content, while the contents of other elements are the same. Specific implementation method four:
[0036] In this embodiment, a dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.6% Cu, 0.04% Sb, with the balance being Fe. Compared with specific embodiment three, this embodiment has a higher Cu content, while the contents of other elements are the same. Specific implementation method five:
[0038] Step 1: Mix and melt pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrisulfide powder, electrolytic copper, and ferroantimony according to the following weight percentages (wt.%): C: 3.0%-3.4%, Si: 1.8%-2.3%, Mn: 0.3%-0.6%, P: 0.13%-0.2%, S: 0.04-0.08%, Cu: 0.3-0.8%, Sb: 0.02-0.06%, with the balance being Fe.
[0039] Step 2: The centrifugal casting method is used for molding. The centrifugal speed during the centrifugal casting process is 1340-1500 rpm, the casting speed is 4.5-5.5 kg / s, and the casting temperature is 1420-1490℃.
[0040] Step 3: After centrifugal casting, a blank is obtained. The blank exits the mold at a temperature of 805-815℃, and the blank structure is in the austenitic state.
[0041] Step 4: After demolding, the blank is air-cooled at 535-585℃, then air-cooled to room temperature, and then annealed at 525-540℃ for 2-3.5 hours to obtain the cylinder liner material. Specific implementation method six:
[0043] Compared with Specific Implementation Method 5, step 1 is the same as Specific Implementation Method 5, except that the ingredients are prepared by weight percentage (wt.%) as follows: 3.3%C, 2.1%Si, 0.35%Mn, 0.14%P, 0.06%S, 0.4%Cu, 0.02%Sb, with the balance being Fe. Specific implementation method seven:
[0045] Compared with Specific Implementation Method 5, step 1 is the same as Specific Implementation Method 5, except that the ingredients are prepared by weight percentage (wt.%) as follows: 3.3%C, 2.1%Si, 0.35%Mn, 0.14%P, 0.06%S, 0.4%Cu, 0.04%Sb, with the balance being Fe. Detailed implementation method eight:
[0047] Compared with Specific Embodiment Five, step 1 is the same as Specific Embodiment Five, except that the ingredients are prepared by weight percentage (wt.%) as follows: 3.3%C, 2.1%Si, 0.35%Mn, 0.14%P, 0.06%S, 0.6%Cu, 0.04%Sb, with the balance being Fe. Specific implementation method nine:
[0049] Compared with Specific Implementation Method 5, in step 2, the centrifugal casting speed is 1460 rpm to ensure good filling effect of molten metal; the casting speed is 5 kg / s to achieve "sequential solidification" and eliminate casting defects; the casting temperature is 1440℃ to ensure that molten metal can quickly fill the mold; the blank exit temperature is 813℃ to prevent the cylinder liner from deforming or cracking due to large thermal stress caused by temperature difference. Other aspects are the same as in Specific Implementation Method 5. Specific Implementation Method Ten:
[0051] Compared with Specific Implementation Method 5, in step 3, after the blank is removed from the mold, it is quickly air-cooled to 560°C and then air-cooled to room temperature. Then, it is annealed in an annealing furnace at 535°C for 2.7 hours. The rest is the same as Specific Implementation Method 5.
[0052] The following embodiments are used to verify the beneficial effects of the present invention:
[0053] Example 1: In this example, a dense pearlitic gray cast iron cylinder liner material is composed of 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.02% Sb by weight percentage (wt.%), with the balance being Fe.
[0054] Its preparation method is as follows:
[0055] Step 1: Mix and melt the raw materials, including pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrite powder, electrolytic copper, and ferroantimony.
[0056] Step 2: Centrifuge the molten iron to obtain a blank. The centrifugal casting speed is 1460 rpm, the casting speed is 5 kg / s, the casting temperature is 1440℃, and the blank exit temperature is 813℃.
[0057] Step 3: After exiting the mold, quickly air-cool the blank to 560℃ and then air-cool it to room temperature. Then, anneal it in an annealing furnace at 535℃ for 2.7 hours to obtain the cylinder liner material.
[0058] Example 2: In this embodiment, a dense pearlitic gray cast iron cylinder liner material is composed of 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.04% Sb by weight percentage (wt.%), with the balance being Fe.
[0059] Its preparation method is as follows:
[0060] Step 1: Mix and melt the raw materials, including pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrite powder, electrolytic copper, and ferroantimony.
[0061] Step 2: Centrifuge the molten iron to obtain a blank. The centrifugal casting speed is 1460 rpm, the casting speed is 5 kg / s, the casting temperature is 1440℃, and the blank exit temperature is 813℃.
[0062] Step 3: After exiting the mold, quickly air-cool the blank to 560℃ and then air-cool it to room temperature. Then, anneal it in an annealing furnace at 535℃ for 2.7 hours to obtain the cylinder liner material.
[0063] Example 3: In this embodiment, a dense pearlitic gray cast iron cylinder liner material is composed of 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.6% Cu, 0.04% Sb by weight percentage (wt.%), with the balance being Fe.
[0064] Its preparation method is as follows:
[0065] Step 1: Mix and melt the raw materials, including pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrite powder, electrolytic copper, and ferroantimony.
[0066] Step 2: Centrifuge the molten iron to obtain a blank. The centrifugal casting speed is 1460 rpm, the casting speed is 5 kg / s, the casting temperature is 1440℃, and the blank exiting the mold temperature is 813℃.
[0067] Step 3: After exiting the mold, quickly air-cool the blank to 560℃ and then air-cool it to room temperature. Then, anneal it in an annealing furnace at 535℃ for 2.7 hours to obtain the cylinder liner material.
[0068] Comparative Example 1: In this example, a dense pearlitic gray cast iron cylinder liner material is composed of 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S by weight percentage (wt.%), with the balance being Fe.
[0069] Its preparation method is as follows:
[0070] Step 1: Mix and melt the raw materials, including pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrite powder, electrolytic copper, and ferroantimony.
[0071] Step 2: Centrifuge the molten iron to obtain a blank. The centrifugal casting speed is 1460 rpm, the casting speed is 5 kg / s, the casting temperature is 1440℃, and the blank exiting the mold temperature is 813℃.
[0072] Step 3: After exiting the mold, quickly air-cool the blank to 560℃ and then air-cool it to room temperature. Then, anneal it in an annealing furnace at 535℃ for 2.7 hours to obtain the cylinder liner material.
[0073] Experiment Summary:
[0074] In contrast, no copper or antimony was added in Example 1, while both Example 2 and Example 3 contained copper and antimony. Furthermore, the copper content in Example 3 was higher than that in Example 2. Figure 1 The diagram shows the pearlite microstructure of Comparative Example 1, Experimental Example 2 and Experimental Example 3. With the addition of copper and antimony, the pearlite lamellars are greatly refined and the microstructure is more compact.
[0075] Figure 2 The figures show the Brinell hardness diagrams for Experimental Examples 1, 2, 3, and Comparative Example 1. The hardness of the gray cast iron cylinder liner material prepared in Comparative Example 1 is 273 HB, while the hardnesses of the gray cast iron cylinder liner materials prepared in Experimental Examples 1, 2, and 3 are 367 HB, 384 HB, and 398 HB, respectively. This is because the addition of copper and antimony elements produces a large amount of dense pearlite structure, and the hardness of the gray cast iron cylinder liner material is greatly improved due to the grain refinement and solid solution strengthening effects.
[0076] Figure 3 The tensile strengths of Experimental Examples 1, 2, 3, and Comparative Example 1 are given. The tensile strength of the gray cast iron cylinder liner prepared in Comparative Example 1 is 325 MPa, while the tensile strengths of the gray cast iron cylinder liners prepared in Experimental Examples 1 and 2 are 409 MPa, 437 MPa, and 486 MPa, respectively. This is because the gray cast iron cylinder material has a more uniform microstructure, which in turn improves its tensile strength.
[0077] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. A dense pearlitic gray cast iron cylinder liner material, characterized in that: The dense pearlitic gray cast iron cylinder liner material is composed of Fe, C, Si, Mn, P, S, Cu and Sb elements, with the chemical formula FeCSiMnPSCuSb. Each element is composed of the following weight percentages (wt.%): C 3.0%-3.4%, Si 1.8%-2.3%, Mn 0.3%-0.6%, P 0.13%-0.2%, S 0.04-0.08%, Cu 0.3-0.8%, Sb 0.02-0.04%, with the balance being Fe.
2. The dense pearlitic gray cast iron cylinder liner material according to claim 1, characterized in that: The dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.02% Sb, with the balance being Fe.
3. The dense pearlitic gray cast iron cylinder liner material according to claim 1, characterized in that: The dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.4% Cu, 0.04% Sb, with the balance being Fe.
4. The dense pearlitic gray cast iron cylinder liner material according to claim 1, characterized in that: The dense pearlitic gray cast iron cylinder liner material is composed of the following weight percentages (wt.%): 3.3% C, 2.1% Si, 0.35% Mn, 0.14% P, 0.06% S, 0.6% Cu, 0.04% Sb, with the balance being Fe.
5. A method for preparing a dense pearlitic gray cast iron cylinder liner material, characterized in that: The preparation method specifically includes the following steps: Step 1: Mix and melt pig iron, scrap steel, ferrosilicon, ferromanganese, ferrophosphorus, ferrisulfide powder, electrolytic copper, and ferroantimony according to the following weight percentages (wt.%): C: 3.0%-3.4%, Si: 1.8%-2.3%, Mn: 0.3%-0.6%, P: 0.13%-0.2%, S: 0.04-0.08%, Cu: 0.3-0.8%, Sb: 0.02-0.06%, with the balance being Fe. Step 2: The centrifugal casting method is used for molding. The centrifugal speed during the centrifugal casting process is 1340-1500 rpm, the casting speed is 4.5-5.5 kg / s, and the casting temperature is 1420-1490℃. Step 3: After centrifugal casting, a blank is obtained. The blank exits the mold at a temperature of 805-815℃, and the blank structure is in the austenitic state. Step 4: After demolding, the blank is air-cooled at 535-585℃, then air-cooled to room temperature, and then annealed at 525-540℃ for 2-3.5 hours to obtain the cylinder liner material.
6. The method for preparing a dense pearlitic gray cast iron cylinder liner material according to claim 5, characterized in that: In steps 2 and 3, the centrifugal casting process involves a centrifugal rotation speed of 1460 rpm, a casting speed of 5 kg / s, a casting temperature of 1440℃, and a blank exit temperature of 813℃.
7. The method for preparing a dense pearlitic gray cast iron cylinder liner material according to claim 5, characterized in that: After exiting the mold in step 4, the blank is air-cooled to 560°C and then air-cooled to room temperature. Then, it is annealed in an annealing furnace at 535°C for 2.7 hours to obtain the cylinder liner material.