Valve seat ring material suitable for methanol engine and preparation method of valve seat ring material

Abstract

The invention relates to the technical field of wear-resistant materials, and discloses a valve seat ring material suitable for a methanol engine and a preparation method thereof, the material comprises the following element raw materials by mass: 0.6-1.8% of C, 4-10% of W, 2-10% of Mo, 5-15% of V, 2-10% of Cr, 0.5-10% of Ni, 10-30% of Co, 10-25% of Cu, 0-1.5% of Mn, and the balance Fe. According to the scheme, carbon powder, tool steel powder, cobalt-molybdenum alloy powder and copper powder are subjected to ball milling to prepare cobalt alloyed matrix powder with excellent heat conductivity, super corrosion resistance and high-temperature wear resistance, and the cobalt alloyed matrix powder prepared through the formula and the process is good in formability and uniform in structure; the cobalt alloying matrix ensures super corrosion resistance, high temperature resistance and wear resistance of the whole matrix, and the copper alloy phase improves the strength and heat-conducting property of the matrix; the valve seat ring material effectively improves corrosion, high temperature and abrasion resistance, and can cope with the working condition of a methanol engine.

Description

Technical Field

[0001] The invention relates to the technical field of wear-resistant materials, and in particular to a valve seat ring material suitable for a methanol engine and a preparation method thereof. Background Art

[0002] Methanol is regarded as clean "coal", cheap "oil", simple "gas", mobile "electricity" and liquid "hydrogen". Methanol fuel vehicles are an important way to achieve "double carbon" in transportation. Methanol corrodes the engine, has poor low-temperature starting performance and a wide range of deflagration limits, which makes it difficult to expand the sales of methanol vehicles.

[0003] However, the existing system of powder metallurgy valve seat rings is difficult to meet the high-temperature wear requirements of methanol engines under corrosive conditions. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a valve seat material suitable for a methanol engine and a preparation method thereof, which can meet the high-temperature wear requirements of the methanol engine under corrosive conditions.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a valve seat material suitable for a methanol engine, comprising element raw materials in the following mass ratios: C: 0.6-1.8%, W: 4-10%, Mo: 2-10%, V: 5-15%, Cr: 2-10%, Ni: 0.5-10%, Co: 10-30%, Cu: 10-25%, Mn: 0-1.5%, Fe: balance.

[0006] Preferably, the raw materials contain the following elemental proportions by mass: C: 1.2%, W: 7%, Mo: 6%, V: 10%, Cr: 6%, Ni: 5%, Co: 20%, Cu: 16%, Mn: 0.7%, Fe: balance.

[0007] Preferably, the material is prepared by ball milling and mixing to prepare cobalt-based alloy powder as a matrix, and is prepared by a powder metallurgy process.

[0008] The second aspect of the present invention provides a method for preparing a valve seat material suitable for a methanol engine, comprising the following steps:

[0009] (1) ball-milling raw material powders in proportion to mix them uniformly, wherein the raw materials include carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder;

[0010] (2) The mixed powder is pressed into a compact on a press with a compact density of 6.4-6.7 g / cm 3 ;

[0011] (3) sintering the formed blank at high temperature in a sintering furnace;

[0012] (4) Cryogenic annealing treatment;

[0013] (5) Machining into a finished product to obtain the material.

[0014] Preferably, the ball milling is performed for 0.5-2 h at a rotation speed of 100-1000 r / min.

[0015] Preferably, the molding density is 6.4-6.7 g / cm 3 .

[0016] Preferably, the sintering temperature is 1100-1150° C., and the sintering time is 1-2 h.

[0017] Preferably, the deep cooling temperature is -120°C and maintained for 30 minutes; the tempering temperature is 450-600°C and maintained for 1.5-2.5 hours.

[0018] Preferably, the raw material contains the following elements in the following mass ratios: C: 0.6-1.8%, W: 4-10%, Mo: 2-10%, V: 5-15%, Cr: 2-10%, Ni: 0.5-10%, Co: 10-30%, Cu: 10-25%, Mn: 0-1.5%, Fe: balance.

[0019] Through the above technical scheme, carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder are used to prepare a cobalt-based alloyed matrix powder with excellent thermal conductivity, super corrosion resistance, and high temperature wear resistance by ball milling. The cobalt-based alloyed matrix powder prepared by this formula and process has good formability and uniform structure. The cobalt-based alloyed matrix ensures the super corrosion resistance, high temperature wear resistance of the entire matrix, and the copper alloy phase improves the strength and thermal conductivity of the matrix. The valve seat ring material of the present invention effectively improves the corrosion and high temperature wear resistance, and can cope with the working conditions of methanol engines.

[0020] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. DETAILED DESCRIPTION

[0021] The specific implementation of the embodiment of the present invention is described in detail below. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0022] Example 1

[0023] A valve seat material suitable for a methanol engine has the following composition, including carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder:

[0024]

[0025] A manufacturing process for valve seat ring materials for methanol engines: ball milling mixing → pressing molding → high temperature sintering → deep cold tempering → machining, as follows:

[0026] (1) The raw material powders were ball-milled and mixed uniformly according to the proportions. The ball milling process was performed for 1.2 hours at a speed of 600 r / min. (2) The mixed powders were pressed into a mold on a press. The molded density was 6.5 g / cm 3 ; (3) high-temperature sintering the formed blank in a sintering furnace, the sintering temperature is 1125°C, and the sintering time is 1.5 hours; (4) deep cold tempering treatment, the deep cold temperature is -120°C, and the temperature is maintained for 30 minutes; the tempering temperature is 530°C, and the temperature is maintained for 2 hours; (5) machining into a finished product.

[0027] Example 2

[0028] A valve seat material suitable for a methanol engine has the following composition, including carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder:

[0029] element C Co W V Cr Mo Ni Cu Fe Content wt% 1.4 18.3 6.3 8.9 4.9 5.3 2.3 18 margin

[0030] A manufacturing process for valve seat ring materials for methanol engines: ball milling mixing → pressing molding → high temperature sintering → deep cold tempering → machining, as follows:

[0031] (1) The raw material powders were ball-milled and mixed evenly according to the proportions, and the ball milling was performed for 0.5 h at a speed of 1000 r / min; (2) The mixed powders were pressed into a mold on a press, and the molded density was 6.4-6.7 g / cm 3 ; (3) high-temperature sintering the formed blank in a sintering furnace, the sintering temperature is 1100°C, and the sintering time is 2h; (4) deep cold tempering treatment, the deep cold temperature is -120°C, and the temperature is maintained for 30min; the tempering temperature is 450°C, and the temperature is maintained for 2.5h; (5) machining into a finished product.

[0032] Example 3

[0033] A valve seat material suitable for a methanol engine has the following composition, including carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder:

[0034] element C Co W V Cr Mo Ni Cu Fe Content wt% 1.6 25.2 8.7 13.1 8.2 8.5 4.1 23 margin

[0035] A manufacturing process for valve seat ring materials for methanol engines: ball milling mixing → pressing molding → high temperature sintering → deep cold tempering → machining, as follows:

[0036] (1) The raw material powders were ball-milled and mixed uniformly according to the proportion, and the ball milling was performed for 2 hours at a speed of 100 r / min; (2) The mixed powders were pressed into a mold on a press, and the molded density was 6.4-6.7 g / cm 3; (3) high-temperature sintering the formed blank in a sintering furnace, the sintering temperature is 1150°C, and the sintering time is 1h; (4) deep cold tempering treatment, the deep cold temperature is -120°C, and the temperature is maintained for 30min; the tempering temperature is 600°C, and the temperature is maintained for 1.5h; (5) machining into a finished product.

[0037] The commercially available reference material WR3119 was used as a comparative example. The samples obtained in the above Examples 1-3 and the reference material WR3119 were subjected to wear resistance tests (valve material: Ni30, test conditions: temperature 500°C, rotation speed 1500rpm, test time 20 hours, wear tester) and machinability tests (test conditions: CBN tool, rotation speed 1000rpm, feed rate 0.1mm / r). The experimental results are shown in the following table:

[0038] Table 1: Wear resistance test results

[0039]

[0040]

[0041] Table 2: Processability test results

[0042]

[0043] It can be seen from the test data that the wear resistance and processing performance of the valve seat ring materials obtained in Examples 1-3 of the present invention are better than those of the reference material. The cobalt-based alloyed matrix prepared by ball milling effectively improves the high-temperature wear resistance of the powder metallurgy seat ring while ensuring thermal conductivity and corrosion resistance. It can cope with harsh engine conditions, especially matching methanol engine conditions, and at the same time greatly improves the processing performance and saves tool costs. However, it is not the case that the wear resistance of the cobalt-based alloy matrix prepared by simply increasing the alloy element content is better. The higher the alloy element content, the steeper the cost, the lower the powder forming performance, the greater the tool loss, and the lower the comprehensive wear resistance. Therefore, only the cobalt-based alloyed matrix prepared by the appropriate formula and process can play the advantages of cost processing and performance balance.

[0044] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A valve seat material suitable for a methanol engine, characterized in that: The invention comprises element raw materials in the following mass ratios: C: 0.6-1.8%, W: 4-10%, Mo: 2-10%, V: 5-15%, Cr: 2-10%, Ni: 0.5-10%, Co: 10-30%, Cu: 10-25%, Mn: 0-1.5%, and Fe: balance.

2. The valve seat material for methanol engine according to claim 1, characterized in that: The raw materials contain the following elemental proportions by mass: C: 1.2%, W: 7%, Mo: 6%, V: 10%, Cr: 6%, Ni: 5%, Co: 20%, Cu: 16%, Mn: 0.7%, and Fe: balance.

3. The valve seat material for methanol engine according to claim 1, characterized in that: The material is prepared by using a powder metallurgy process and using cobalt alloy powder as a matrix prepared by ball milling and mixing.

4. A method for preparing a valve seat material suitable for a methanol engine, characterized in that: The process includes: (1) ball-milling raw material powders in proportion to mix them uniformly, wherein the raw materials include carbon powder, tool steel powder, cobalt-molybdenum alloy powder, and copper powder; (2) Pressing the mixed powder into a shape on a press; (3) sintering the formed blank at high temperature in a sintering furnace; (4) Deep cold tempering treatment; (5) Machining into a finished product to obtain the material.

5. The method for preparing a valve seat material for a methanol engine according to claim 4, characterized in that: The ball milling is performed for 0.5-2h at a rotation speed of 100-1000r / min.

6. The method for preparing a valve seat material suitable for a methanol engine according to claim 4, characterized in that: The molding density is 6.4-6.7g / cm 3 .

7. The method for preparing a valve seat material for a methanol engine according to claim 4, characterized in that: The sintering temperature is 1100-1150° C., and the sintering time is 1-2 hours.

8. The method for preparing a valve seat material for a methanol engine according to any one of claims 4 to 7, characterized in that: The deep cooling temperature is -120°C and maintained for 30 minutes; the tempering temperature is 450-600°C and maintained for 1.5-2.5 hours.

9. The method for preparing a valve seat material for a methanol engine according to claim 8, characterized in that: The raw material contains the following elements in the following mass ratios: C: 0.6-1.8%, W: 4-10%, Mo: 2-10%, V: 5-15%, Cr: 2-10%, Ni: 0.5-10%, Co: 10-30%, Cu: 10-25%, Mn: 0-1.5%, and Fe: balance.

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