Novel split type steel cylinder sleeve with carbon scraping ring and preparation method of novel split type steel cylinder sleeve

Abstract

The invention discloses a novel split type steel cylinder sleeve with a carbon scraping ring and a preparation method of the novel split type steel cylinder sleeve. The cylinder sleeve comprises a hollow cylinder sleeve large end, a cylinder sleeve small end and a carbon scraping ring located in an inner cavity, the outer diameter of the cylinder sleeve large end is larger than that of the cylinder sleeve small end, and the arc of the lower end face of the cylinder sleeve large end is located in a friction welding heat affected area. During preparation, a steel pipe is selected according to the size allowance of a finished product, subjected to high-frequency quenching and sawed off to form a semi-finished product of the cylinder sleeve before friction welding, then the large end and the small end of the cylinder sleeve are connected through the friction welding technology, friction welding parameters are strictly controlled, and then the clamping allowance of a large-end friction welding clamp is removed from the semi-finished product of the cylinder sleeve; and finally, honing and phosphating are carried out, and a finished product is obtained. The hardness and wear resistance of the carbon scraping ring are greatly improved, the service life is prolonged, the installation cost is saved, the reliability of the cylinder sleeve is enhanced, high performance and low cost of the cylinder sleeve are achieved, and the method is suitable for green and energy-saving batch production.

Description

Technical Field

[0001] The invention relates to the technical field of engine parts production, in particular to a novel split steel cylinder liner with a self-contained carbon scraping ring and a preparation method thereof. Background Art

[0002] The cylinder liner is one of the key parts of the engine. It is located in the "heart" of the engine and together with the piston and cylinder head, it forms a closed cylinder working space. Its main function is to withstand the gas pressure and drive the crankshaft to rotate through the piston-connecting rod mechanism to provide power. The cylinder liner is subjected to alternating mechanical and thermal loads during operation, and is under high temperature, high pressure, high speed and poor lubrication for a long time, so the working conditions are very harsh. With the continuous increase in the specific power and explosion pressure of diesel engines, the wear problem of the inner wall of the cylinder liner and the piston is becoming more and more serious, and serious carbon deposition often occurs on the surface of the piston head. This carbon deposition not only aggravates the wear of the inner wall of the cylinder liner and the piston, but also leads to an increase in lubricating oil consumption, and may cause premature wear, cavitation, cylinder collapse and other failure problems of the wet cylinder liner, which eventually leads to scrapping.

[0003] In order to solve the carbon deposit problem, the design of cylinder liner with carbon scraper ring came into being. When the carbon deposit on the piston head reaches a certain thickness, the carbon scraper ring can scrape it off during the reciprocating motion of the piston, thereby avoiding the formation of a thicker layer of carbon deposit. The scraped carbon deposit is blown away by the exhaust gas. However, the carbon scraper ring is also subjected to the high temperature and high pressure fuel during operation, so it will have a certain wear and tear, and carbon deposits may form on its own surface. This makes the carbon scraper ring one of the vulnerable parts of the engine. In addition, the reliability of the cylinder liner directly determines the reliability of the engine. Among the failure modes of the cylinder liner, the fracture of the support shoulder is a very dangerous failure mode. It can damage the piston and piston ring at the least, and may damage key components such as the cylinder block, cylinder head and connecting rod at the worst.

[0004] Therefore, how to improve the performance of the cylinder liner carbon scraper ring, including tensile strength, elastic modulus, plasticity, corrosion resistance, wear resistance, anti-friction, thermal conductivity and thermal fatigue resistance, so as to extend its service life and reduce the frequency of replacement due to wear, corrosion, thermal fatigue and other failures, is an important research direction for major OEMs and their parts manufacturers. At the same time, how to improve the strength of the cylinder liner support shoulder and reduce the risk of support shoulder fracture is also the key to improving the performance of the cylinder liner. Summary of the invention

[0005] The present invention is mainly aimed at the above problems existing in the prior art, and provides a novel split steel cylinder liner with a self-contained carbon scraping ring and a preparation method thereof.

[0006] The purpose of the present invention is mainly achieved through the following solutions: In the first aspect, the present application provides a novel split steel cylinder liner with a self-contained carbon scraping ring, which adopts the following technical solution: A novel split steel cylinder liner with a carbon scraping ring comprises a hollow cylindrical cylinder liner big end and a cylinder liner small end, and a carbon scraping ring formed by friction welding and machining, wherein the carbon scraping ring is located in the inner cavity of the cylinder liner, the outer diameter of the cylinder liner big end is larger than the outer diameter of the cylinder liner small end, and the arc of the lower end surface of the cylinder liner big end is located within the heat affected zone generated by friction welding.

[0007] In a second aspect, the present application provides a method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring, using the following technical solution: The following steps are involved: S1. Preparation of the big end and small end blanks of the cylinder liner: Select steel pipe 1 with the same inner and outer diameter size according to the size of the finished cylinder liner big end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin for the inner diameter; select steel pipe 2 with the same inner and outer diameter size according to the size of the finished cylinder liner small end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin for the inner diameter; S2. High-frequency quenching treatment of steel pipe 1 and steel pipe 2: The inner holes of steel pipe 1 and steel pipe 2 are subjected to high-frequency quenching treatment, the depth of the quenching layer is 1.5-2mm, and the hardness of the quenching layer is determined according to the material; S3, preparation of semi-finished products before welding of the big end and small end of the cylinder liner: sawing the steel pipe 1 after the inner bore quenching into the required length to form the big end steel pipe of the cylinder liner, and sawing the steel pipe 2 into the required length to form the small end steel pipe of the cylinder liner; S4. Friction welding of the big end and small end of the cylinder liner: The big end steel pipe of the cylinder liner and the small end steel pipe of the cylinder liner are connected by friction welding. The welding shortening is greater than 1mm, the width of the welding heat affected zone is greater than 3mm, and the edge of the welding surface is chamfered with an arc of R0.5-5.0mm. The hardness and strength of the welding area are greater than the hardness and strength of the base materials of the big end and small end of the cylinder liner; S5. Machining of semi-finished products: First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face of the cylinder liner are processed; S6. Finishing of semi-finished products: Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. The hardness of the carbon scraping ring is greater than the hardness of the base material of the large end and small end of the cylinder liner; S7. Preparation of finished cylinder liner: Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern. The honed cylinder liner is phosphated and finally inspected for size to obtain a finished steel cylinder liner.

[0008] Preferably, in step S3, the sawing length of the steel pipe 1 is the length of the large end of the cylinder liner + half of the shortening amount of welding + the clamping length of the friction welding tooling, and the sawing length of the steel pipe 2 is the length of the small end of the cylinder liner + half of the shortening amount of welding.

[0009] Preferably, in step S4, the welding surface roughness Rz is 25-90 μm, the welding surface is set to an arc of R100 mm or a plane with chamfers, and the dimensional tolerance of the welding surface is not greater than ±0.05 mm.

[0010] Preferably, the friction welding technology is used in step S4, comprising the following steps: a. Clean the inner holes of the semi-finished products at the large and small ends of the cylinder liner to ensure the cleanliness of the welding surface. The maximum impurity particle size is less than 850μm and the weight of the impurities is less than 15mg; b. Friction welding is used to connect the big and small ends of the cylinder liner. The width of the welding burr is greater than the width of the carbon scraping ring required by the drawing, the height of the welding burr is greater than the height of the carbon scraping ring required by the drawing, and the welding root height is greater than 0.5mm.

[0011] Preferably, the welding amount of the cylinder liner big end and the cylinder liner small end is 1-10 mm.

[0012] Preferably, the width of the support shoulder at the small end of the cylinder liner is 3-6 mm, and the thickness of the support shoulder is 2-3 mm.

[0013] Preferably, in step S7, the cylinder liner is phosphated by high-temperature manganese-phosphorus co-diffusion technology, the roughness Rz of the cylinder liner surface is greater than 100 μm, and the thickness of the manganese-phosphorus co-diffusion layer is 2-10 μm.

[0014] Preferably, in step S1, the materials of the cylinder liner big end and the cylinder liner small end are low carbon steel, high carbon steel, alloy steel, ceramic material or other materials that can be friction welded, and the materials of the cylinder liner big end and the cylinder liner small end can be arbitrarily combined.

[0015] Therefore, compared with the prior art, the present invention has the following advantages: (1) The present invention adopts a structural design with a self-contained carbon scraper ring, which not only saves the installation and connection costs of the carbon scraper ring, but also greatly improves the hardness and wear resistance of the carbon scraper ring, thereby effectively improving the carbon scraping effect and service life of the carbon scraper ring; (2) The present invention adopts friction welding technology to improve the welding strength between the big end and the small end of the cylinder liner, thereby ensuring the reliability of the cylinder liner. At the same time, the lower end surface of the big end of the cylinder liner is located within the welding heat-affected zone, which strengthens the arc of the lower end surface of the big end of the cylinder liner, greatly reduces the occurrence of failure of the cylinder liner falling off, and improves the overall strength and reliability of the cylinder liner. (3) The present invention achieves the optimal combination of cylinder liner performance by combining different materials, that is, selecting a suitable material combination to achieve a new way to improve the failures of the cylinder liner such as cavitation, high temperature deformation, and wear, thereby improving the carbon deposition resistance, wear resistance, and thermal fatigue resistance of the cylinder liner, thereby extending the service life of the cylinder liner; (4) The preparation method provided by the present invention is simple and efficient, can realize green and energy-saving mass production, and has low manufacturing and processing costs. It not only solves the technical problems of insufficient performance of the scraping ring in the traditional cylinder liner, high installation cost and low strength of the cylinder liner support shoulder, but also simplifies the design of the cylinder liner and its scraping ring, that is, simplifies the engine design, improves the overall performance and life of the engine, and achieves a good effect of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a semi-finished product of the welded cylinder liner in the present invention; Figure 2 It is the finished product of the cylinder sleeve in the present invention; Figure 3 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 1; Figure 4 This is a metallographic structure photograph of the small end of the cylinder liner in the finished cylinder liner of Example 1 (100 times); Figure 5 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 1 (100 times); Figure 6 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 1 (500 times); Figure 7 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 2; Figure 8 This is a metallographic structure photograph (100 times) of the small end of the cylinder liner in the finished cylinder liner of Example 2; Fig. 9 This is a metallographic photograph of the weld area in the finished cylinder liner of Example 2 (100 times); Fig.10 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 2 (500 times); Fig.11 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 3; Fig.12 This is a metallographic structure photograph of the small end of the cylinder liner in the finished cylinder liner of Example 3 (100 times); Fig.13 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 3 (100 times); Fig.14This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 3 (500 times); Fig.15 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 4; Fig.16 This is a metallographic structure photograph (100 times) of the small end of the cylinder liner in the finished cylinder liner of Example 4; Fig.17 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 4 (100 times); Fig.18 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 4 (500 times); Fig.19 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 5; Fig. 20 This is a metallographic structure photograph (100 times) of the small end of the cylinder liner in the finished cylinder liner of Example 5; Fig.21 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 5 (100 times); Fig. 22 This is a metallographic photograph of the weld area in the finished cylinder liner of Example 5 (500 times); Fig.23 This is a metallographic structure photograph (100 times) of the big end of the cylinder liner in the finished cylinder liner of Example 6; Fig.24 This is a metallographic structure photograph of the small end of the cylinder liner in the finished cylinder liner of Example 6 (100 times); Fig.25 This is a metallographic structure photograph of the weld area in the finished cylinder liner of Example 6 (100 times); Fig.26 This is a metallographic structure photograph (500 times) of the weld area in the finished cylinder liner of Example 6.

[0017] Illustration: 1-big end of cylinder liner, 2-small end of cylinder liner, 3-carbon scraper ring, 4-support shoulder. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0019] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods.

[0020] like Figure 1 , 2 A new type of split steel cylinder liner with a carbon scraping ring is shown, comprising a hollow cylindrical cylinder liner big end 1 and a cylinder liner small end 2, and a carbon scraping ring 3 formed by friction welding and machining. The carbon scraping ring 3 is located in the inner cavity of the cylinder liner, the outer diameter of the cylinder liner big end 1 is larger than the outer diameter of the cylinder liner small end 2, and the arc of the lower end surface of the cylinder liner big end 1 is located within the heat affected zone generated by friction welding.

[0021] The present application also discloses a method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring, comprising the following steps: S1. Preparation of the blanks of the big end 1 and the small end 2 of the cylinder liner: Select a steel pipe 1 with the same inner and outer diameter size and model according to the size of the big end 1 of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin for the inner diameter; select a steel pipe 2 with the same inner and outer diameter size and model according to the size of the small end 2 of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin for the inner diameter. It should be noted here that different margins can be selected according to the specific deformation of each material during high-frequency quenching, and if the material hardness and wear resistance are suitable, the subsequent high-frequency quenching treatment of the inner hole may not be performed; S2. High-frequency quenching treatment of steel pipe 1 and steel pipe 2: The inner holes of steel pipe 1 and steel pipe 2 are subjected to high-frequency quenching treatment. The depth of the quenching layer is 1.5-2mm, which is determined according to the inner hole processing and honing allowance of the cylinder sleeve. It is generally 0.5-1mm larger than the allowance. The hardness of the quenching layer is determined according to the material; S3, preparation of semi-finished products before welding of cylinder liner big end 1 and cylinder liner small end 2: sawing the steel pipe 1 after inner bore quenching into required length to form cylinder liner big end 1 steel pipe, sawing the steel pipe 2 into required length to form cylinder liner small end 2 steel pipe; S4. Friction welding of the cylinder liner big end 1 and the cylinder liner small end 2: connect the cylinder liner big end 1 steel pipe and the cylinder liner small end 2 steel pipe by friction welding, the welding shortening is greater than 1mm, the welding heat affected zone width is greater than 3mm, and the edge of the welding surface is added with an arc chamfer of R0.5-5.0mm. The appropriate chamfer is determined according to the cylinder liner size and welding area. The hardness and strength of the welding area are greater than the hardness and strength of the cylinder liner big end 1 and small end substrates; S5. Machining of semi-finished products: First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is first removed, which is generally 8-15mm, and then the external welding flash is removed according to the drawing, and the outer circle and end face of the cylinder liner are processed; S6. Finishing of semi-finished products: The welding flash of the inner hole of the cylinder liner is processed into a carbon scraping ring 3 with the size required by the drawing. The hardness of the carbon scraping ring 3 is greater than the hardness of the base material of the big end 1 and the small end of the cylinder liner, generally greater than 500HV1. It is related to the material of the big end and the small end of the cylinder liner. The hardness of the flash on both sides can also be different. S7. Preparation of finished cylinder liner: Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern. The honing cylinder liner is phosphated and finally inspected for size to obtain a finished steel cylinder liner. The use of a stepped honing head can avoid affecting the shape and size of the carbon scraper ring.

[0022] In the present invention, the sawing length of the steel pipe 1 in step S3 is the length of the large end 1 of the cylinder liner + half of the welding shortening + the clamping length of the friction welding tooling, and the clamping length of the friction welding tooling is generally 8-15mm. The sawing length of the steel pipe 2 is the length of the small end 2 of the cylinder liner + half of the welding shortening.

[0023] In the present invention, in step S4, the welding surface roughness Rz is 25-90 μm, the welding surface is set to be an arc of R100 mm or a plane with chamfers, and the dimensional tolerance of the welding surface is not greater than ±0.05 mm.

[0024] In the present invention, friction welding technology is used in step S4, which includes the following steps: a. Clean the inner holes of the semi-finished products at the large end and small end of the cylinder liner to ensure the cleanliness of the welding surface. The maximum impurity particle size is less than 850μm and the weight of the impurities is less than 15mg; b. Use friction welding to connect the big end 1 and the small end of the cylinder liner. The width of the welding flash is greater than the width of the carbon scraping ring required by the drawing, the height of the welding flash is greater than the height of the carbon scraping ring required by the drawing, and the welding root height is greater than 0.5mm.

[0025] In the present invention, the welding amount of the cylinder liner big end 1 and the cylinder liner small end 2 is 1-10 mm.

[0026] In the present invention, the width of the support shoulder 4 at the small end 2 of the cylinder liner is 3-6 mm, and the thickness of the support shoulder 4 is 2-3 mm. The support shoulder plays a role in positioning and applying welding pressure during friction welding of the cylinder liner. The support shoulder will be removed during the machining process after welding.

[0027] In the present invention, in step S7, the cylinder liner is phosphated by high-temperature manganese-phosphorus co-diffusion technology, the roughness Rz of the cylinder liner surface is greater than 100 μm, and the thickness of the manganese-phosphorus co-diffusion layer is 2-10 μm.

[0028] In the present invention, in step S1, the materials of the cylinder liner big end 1 and the cylinder liner small end 2 are low carbon steel, high carbon steel, alloy steel, ceramic material or other materials that can be friction welded, and the materials of the cylinder liner big end 1 and the cylinder liner small end 2 can be arbitrarily combined.

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific applications: Embodiment 1: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the big end of the cylinder liner is 20# steel, and the blank of the small end of the cylinder liner is bainitic steel. According to the outer diameter of the big end of the finished cylinder liner, a 0.5-1mm margin is reserved, and the inner diameter is reserved. A steel pipe 1 (20# steel) with the same inner and outer diameter size model is selected. According to the outer diameter of the small end of the finished cylinder liner, a 0.5-1mm margin is reserved, and the inner diameter is reserved. A steel pipe 2 (bainitic steel) with the same inner and outer diameter size model is selected; S2. Perform high-frequency quenching treatment on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 30-40HRC, and the quenching layer hardness of steel pipe 2 is 50-60HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 10mm, and an arc chamfer of R3mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0030] Figure 3This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Figure 4 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Figure 5 This is a metallographic photograph of the weld area in this embodiment (100 times); Figure 6 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0031] Embodiment 2: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the big end of the cylinder liner is 45# steel, and the blank of the small end of the cylinder liner is bainitic steel. According to the size of the big end of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter, select the steel pipe 1 (45# steel) with the same inner and outer diameter size model. According to the size of the small end of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter, select the steel pipe 2 (bainitic steel) with the same inner and outer diameter size model. S2. Perform high-frequency quenching treatment on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 40-50HRC, and the quenching layer hardness of steel pipe 2 is 50-60HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 16mm, and an arc chamfer of R4mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0032] Figure 7This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Figure 8 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Fig. 9 This is a metallographic photograph of the weld area in this embodiment (100 times); Fig.10 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0033] Embodiment 3: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the big end of the cylinder liner is 50# steel, and the blank of the small end of the cylinder liner is bainitic steel. According to the size of the big end of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter, select the steel pipe 1 (50# steel) with the same inner and outer diameter size model. According to the size of the small end of the finished cylinder liner with a 0.5-1mm margin for the outer diameter and the inner diameter, select the steel pipe 2 (bainitic steel) with the same inner and outer diameter size model. S2. Perform high-frequency quenching treatment on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 40-50HRC, and the quenching layer hardness of steel pipe 2 is 50-60HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 17mm, and an arc chamfer of R3.5mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0034] Fig.11This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Fig.12 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Fig.13 This is a metallographic photograph of the weld area in this embodiment (100 times); Fig.14 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0035] Embodiment 4: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the big end of the cylinder liner is 20# steel, and the blank of the small end of the cylinder liner is 40Cr quenched and tempered steel. According to the size of the finished cylinder liner big end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin, select the steel pipe 1 (20# steel) of the same inner and outer diameter size model. According to the size of the finished cylinder liner small end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin, select the steel pipe 2 (40Cr quenched and tempered steel) of the same inner and outer diameter size model. S2, high frequency quenching treatment is performed on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 30-40HRC, and the quenching layer hardness of steel pipe 2 is 50-60HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 12mm, and an arc chamfer of R3mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0036] Fig.15This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Fig.16 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Fig.17 This is a metallographic photograph of the weld area in this embodiment (100 times); Fig.18 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0037] Embodiment 5: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the big end of the cylinder liner is 20# steel, and the blank of the small end of the cylinder liner is 42CrMo quenched and tempered steel. According to the size of the finished cylinder liner big end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin, select the steel pipe 1 (20# steel) of the same inner and outer diameter size model. According to the size of the finished cylinder liner small end with a 0.5-1mm margin for the outer diameter and the inner diameter with a 0.5-1mm margin, select the steel pipe 2 (42CrMo quenched and tempered steel) of the same inner and outer diameter size model. S2, high frequency quenching treatment is performed on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 30-40HRC, and the quenching layer hardness of steel pipe 2 is 50-60HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 13mm, and an arc chamfer of R3.5mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0038] Fig.19 This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Fig. 20 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Fig.21 This is a metallographic photograph of the weld area in this embodiment (100 times); Fig. 22 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0039] Embodiment 6: A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring comprises the following steps: S1. The material of the cylinder liner big end is 20# steel, and the cylinder liner small end blank is 45# steel. According to the size of the finished cylinder liner big end outer diameter with a reserve of 0.5-1mm and the inner diameter with a reserve of 0.5-1mm, select the steel pipe 1 (20# steel) of the same inner and outer diameter size model. According to the size of the finished cylinder liner small end outer diameter with a reserve of 0.5-1mm and the inner diameter with a reserve of 0.5-1mm, select the steel pipe 2 (45# steel) of the same inner and outer diameter size model. S2. Perform high-frequency quenching treatment on the inner holes of steel pipe 1 and steel pipe 2, the quenching layer depth is 1.5-2mm, the quenching layer hardness of steel pipe 1 is 30-40HRC, and the quenching layer hardness of steel pipe 2 is 45-55HRC; S3, sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner line segment steel pipe, wherein the sawing length of the steel pipe 1 is the length of the cylinder liner big end plus half of the welding shortening, and the sawing length of the steel pipe 2 is the length of the cylinder liner small end plus half of the welding shortening; S4. Connect the cylinder liner big end steel pipe and the cylinder liner small end steel pipe by friction welding, with a welding shortening of 5mm, a welding heat affected zone width of 9mm, and an arc chamfer of R3.5mm on the edge of the welding surface to ensure that the arc at the lower end of the cylinder liner big end is within the welding heat affected zone, and the hardness and strength of the welding area are greater than the hardness and strength of the base material of the cylinder liner big end and small end; S5. First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture of the large end of the cylinder liner 1 is removed first, and then the external welding flash is removed according to the drawing, and the outer circle and end face size of the cylinder liner are processed; S6. Process the welding flash of the inner hole of the cylinder liner into a carbon scraping ring with the size required by the drawing. Due to the fast cooling rate of friction welding, the hardness of the heat-affected zone of the weld is significantly higher than that of the substrate. The hardness of the carbon scraping ring 3 is greater than the hardness of the substrate at the large end 1 and the small end of the cylinder liner. S7. Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern, perform phosphating treatment and final size inspection on the cylinder liner after the inner hole is honed, and obtain the steel cylinder liner in this embodiment.

[0040] Fig.23 This is a metallographic structure photo of the big end of the cylinder liner in this embodiment (100 times); Fig.24 This is a metallographic structure photo of the small end of the cylinder liner in this embodiment (100 times); Fig.25 This is a metallographic photograph of the weld area in this embodiment (100 times); Fig.26 This is a metallographic photograph of the weld area in this embodiment (500 times).

[0041] The strength of the finished cylinder liner has shown excellent performance after fatigue testing. After running for 1200 hours in the engine bench test, the wear of the inner wall of the cylinder liner is significantly less than that of the traditional cylinder liner, and the carbon deposits on the piston head are significantly reduced, which effectively verifies the advantages of the present invention. The final product was installed and tested on another engine, and also achieved excellent results. Within the operating cycle of 600,000 kilometers, there were no failure problems such as support shoulder fracture and cavitation. The carbon scraping ring always maintained good carbon scraping performance, and the lubricating oil consumption was significantly reduced compared with similar engines, further proving the adaptability and excellent performance of the present invention to different materials.

[0042] It should be understood that this embodiment is only used to illustrate the present invention and is not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A new type of split steel cylinder liner with a carbon scraping ring, characterized in that: The invention comprises a cylindrical cylinder liner big end (1) and a cylinder liner small end (2) with a hollow interior, and a carbon scraping ring (3) formed by friction welding and machining, wherein the carbon scraping ring (3) is located in the inner cavity of the cylinder liner, the outer diameter of the cylinder liner big end (1) is larger than the outer diameter of the cylinder liner small end (2), and the arc of the lower end surface of the cylinder liner big end (1) is located within the heat affected zone generated by friction welding.

2. A method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring, characterized in that: The following steps are involved: S1. Preparation of the blanks of the cylinder liner big end (1) and the cylinder liner small end (2): Select a steel pipe 1 with the same inner and outer diameter size and model according to the size of the finished cylinder liner big end (1) with a 0.5-1mm margin for the outer diameter and a 0.5-1mm margin for the inner diameter; select a steel pipe 2 with the same inner and outer diameter size and model according to the size of the finished cylinder liner small end (2) with a 0.5-1mm margin for the outer diameter and a 0.5-1mm margin for the inner diameter; S2. High-frequency quenching treatment of steel pipe 1 and steel pipe 2: The inner holes of steel pipe 1 and steel pipe 2 are subjected to high-frequency quenching treatment, the depth of the quenching layer is 1.5-2mm, and the hardness of the quenching layer is determined according to the material; S3, preparation of semi-finished products of the cylinder liner big end (1) and the cylinder liner small end (2) before welding: sawing the steel pipe 1 after the inner bore quenching into the required length to form the cylinder liner big end (1) steel pipe, and sawing the steel pipe 2 into the required length to form the cylinder liner small end (2) steel pipe; S4. Friction welding of the cylinder liner big end (1) and the cylinder liner small end (2): the cylinder liner big end (1) steel pipe and the cylinder liner small end (2) steel pipe are connected by friction welding, the welding shortening is greater than 1 mm, the width of the welding heat affected zone is greater than 3 mm, the edge of the welding surface is increased with an arc chamfer of R0.5-5.0 mm, and the hardness and strength of the welding area are greater than the hardness and strength of the base materials of the cylinder liner big end (1) and the cylinder liner small end (2); S5. Machining of semi-finished products: First, the end face needs to be offset, that is, the clamping allowance of the friction welding fixture at the large end of the cylinder liner (1) is removed, and then the external welding flash is removed according to the drawing, and the outer circle and end face of the cylinder liner are processed; S6, finishing of the semi-finished product: processing the welding flash of the inner hole of the cylinder liner into a carbon scraping ring (3) with the size required by the drawing, the hardness of the carbon scraping ring (3) being greater than the hardness of the base material of the cylinder liner big end (1) and the cylinder liner small end (2); S7. Preparation of finished cylinder liner: Use a stepped honing head to hone the inner hole of the cylinder liner to obtain a mesh pattern. The honed cylinder liner is phosphated and finally inspected for size to obtain a finished steel cylinder liner.

3. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 2 is characterized in that: In step S3, the sawing length of the steel pipe 1 is the length of the large end (1) of the cylinder liner + half of the shortening amount by welding + the clamping length of the friction welding tooling, and the sawing length of the steel pipe 2 is the length of the small end (2) of the cylinder liner + half of the shortening amount by welding.

4. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 2 is characterized in that: In the step S4, the welding surface roughness Rz is 25-90 μm, the welding surface is set to be an arc of R100 mm or a plane with chamfers, and the dimensional tolerance of the welding surface is not greater than ±0.05 mm.

5. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 2 is characterized in that: The friction welding technology is adopted in step S4, and the steps include: a. Clean the inner holes of the semi-finished product at the large end (1) and small end of the cylinder liner to ensure the cleanliness of the welding surface. The maximum impurity particle size is less than 850 μm and the weight of the impurities is less than 15 mg. b. Use friction welding to connect the big end (1) and the small end of the cylinder liner. The width of the welding burr is greater than the width of the carbon scraping ring required by the drawing. The height of the welding burr is greater than the height of the carbon scraping ring required by the drawing. The welding root height is greater than 0.5 mm.

6. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 5 is characterized in that: The welding amount of the cylinder liner big end (1) and the cylinder liner small end (2) is 1-10 mm.

7. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 6 is characterized in that: The width of the support shoulder (4) at the small end (2) of the cylinder sleeve is 3-6 mm, and the thickness of the support shoulder (4) is 2-3 mm.

8. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 2 is characterized in that: In the step S7, the cylinder liner is phosphated by high temperature manganese-phosphorus co-diffusion technology, the roughness Rz of the cylinder liner surface is greater than 100 μm, and the thickness of the manganese-phosphorus co-diffusion layer is 2-10 μm.

9. The method for preparing a novel split steel cylinder liner with a self-contained carbon scraping ring according to claim 2 is characterized in that: In step S1, the materials of the cylinder liner big end (1) and the cylinder liner small end (2) are low carbon steel, high carbon steel, alloy steel, ceramic material or other materials that can be friction welded, and the materials of the cylinder liner big end (1) and the cylinder liner small end (2) can be any combination.

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