Search

CN-122013097-A - High-wear-resistance air compressor crankshaft and processing method thereof

CN122013097ACN 122013097 ACN122013097 ACN 122013097ACN-122013097-A

Abstract

The invention discloses a processing method of a high wear-resistant air compressor crankshaft, which is characterized by comprising the following operation steps of front end shaft surface pretreatment, crank arm surface pretreatment, rear end shaft surface pretreatment and integral assembly of the crankshaft, wherein the front end shaft surface pretreatment, the crank arm surface pretreatment and the rear end shaft surface pretreatment all comprise oxygen-nitrogen co-permeation methods, the oxygen-nitrogen co-permeation methods comprise salt baths, and the salt bath formula comprises 30% -50% of urea, 20% -40% of potassium nitrate, 10% -30% of sodium carbonate and 5% -15% of lanthanum trifluoride according to weight percentage. The invention processes the surface layers of parts of each part of the crankshaft to improve the wear resistance of the air compressor crankshaft when the air compressor crankshaft operates under high strength and prolong the service life of the air compressor crankshaft.

Inventors

  • WANG YONGMING
  • WANG HUI

Assignees

  • 新昌县日月机械有限公司

Dates

Publication Date
20260512
Application Date
20250612

Claims (10)

  1. 1. A processing method of a high wear-resistant air compressor crankshaft is characterized by comprising the following operation steps of front end shaft surface pretreatment, crank arm surface pretreatment, rear end shaft surface pretreatment and integral assembly of the crankshaft; The front end shaft surface pretreatment, the crank arm surface pretreatment and the rear end shaft surface pretreatment all comprise oxygen-nitrogen co-permeation methods; the oxygen-nitrogen co-permeation method comprises a salt bath, wherein the salt bath comprises, by weight, 30% -50% of urea, 20% -40% of potassium nitrate, 10% -30% of sodium carbonate and 5% -15% of lanthanum trifluoride.
  2. 2. A highly wear resistant air compressor crankshaft as set forth in claim 1 wherein said front end shaft skin pretreatment includes the steps of: s1, performing ultrasonic cleaning on a front end shaft blank, and then performing sand blasting treatment and vacuum annealing to obtain the front end shaft blank with the surface purified: S2, carrying out salt bath on the front-end shaft blank after surface purification, and carrying out low-temperature nitriding and high-temperature oxygen expansion operation, wherein a composite layer with Fe 3 O 4 and epsilon-Fe 2-3 N is formed on the surface of the front-end shaft blank, and in the low-temperature nitriding operation, an enclosed space is protected by argon, in the high-temperature oxygen expansion operation, the enclosed space is NH 3 and CO 2 , and the gas volume ratio of NH 3 to CO 2 is 3:1; And S3, carrying out high-frequency quenching, low-temperature tempering, mechanical polishing and micro-arc oxidation on the front end shaft blank with the Fe 3 O 4 and epsilon-Fe 2-3 N composite layer, so as to obtain the front end shaft with the pretreated surface layer.
  3. 3. The highly wear-resistant air compressor crankshaft as set forth in claim 2, wherein said front end shaft surface layer pretreatment process comprises: The high-frequency quenching parameters comprise the heating rate of the heating surface of 80-120 ℃ per second, the target temperature of 860 ℃ plus or minus 30 ℃, the spraying cooling of 0.1% polyvinyl alcohol aqueous solution, the pressure of 0.3-0.5MPa and the cooling speed of more than or equal to 200 ℃ per second; the low-temperature tempering parameters are that the temperature is 180 ℃ plus or minus 20 ℃ and the vacuum tempering is carried out for 1-3 hours, and the temperature rising rate is less than or equal to 50 ℃ per hour; The mechanical polishing step comprises the steps of grinding diamond grinding paste; The micro-arc oxidation parameters are that the electrolyte formula (comprising Na 2 SiO 3 and KOH) has the voltage of 450V and the time of 0.5-1.5h.
  4. 4. A highly wear resistant air compressor crankshaft as set forth in claim 1 wherein said crank arm skin pretreatment includes the following operative steps: S1, performing ultrasonic cleaning on a crank arm blank, and then performing sand blasting treatment and vacuum annealing to obtain a crank arm blank with a purified surface: S2, carrying out salt bath on the crank arm blank with the surface purified, and carrying out low-temperature nitriding and high-temperature diffusion operations, wherein a composite layer with Fe 4 N and LaN is formed on the surface of the crank arm blank, in the low-temperature nitriding operation, an enclosed space is protected by argon, in the high-temperature diffusion operation, the enclosed space is NH 3 and CO 2 , and the gas volume ratio of NH 3 to CO 2 is 3:1; And S3, carrying out laser scanning on the crank arm blank with the Fe 4 N and LaN composite layer, and then adopting gradient rolling and low-temperature tempering and polishing treatment to obtain the surface-treated crank arm blank.
  5. 5. A highly wear resistant air compressor crankshaft as set forth in claim 4 wherein said crank arm surface layer is pretreated; The laser scanning parameters are that the wavelength of the optical fiber laser is 1064nm, the power is 450-550W, the scanning speed is 1.5-2.5m/s, the distance is 150-250 mu m, and the depth is 3-8 mu m; The gradient rolling parameters comprise rolling force 2600-3000N, a roller type of hard alloy roller with the surface coated with Al 2 O 3 , a pressing depth of 0.3mm and a feeding amount of 0.08mm/r.
  6. 6. A highly wear resistant air compressor crankshaft as set forth in claim 1 wherein said rear end shaft skin pretreatment includes the steps of: s1, performing ultrasonic cleaning on the rear end shaft blank, and then performing sand blasting treatment and vacuum annealing to obtain the rear end shaft blank with the surface purified: S2, carrying out salt bath on the rear end shaft blank after surface purification, and carrying out low-temperature nitriding and high-temperature diffusion operation, wherein a composite layer with gamma' -Fe 4 N and Cr 2 O 3 is formed on the surface of the rear end shaft blank, and in the low-temperature nitriding operation, an enclosed space is protected by argon, in the high-temperature diffusion operation, the enclosed space is NH 3 and CO 2 , and the gas volume ratio of NH 3 to CO 2 is 1:1; and S3, rolling the rear end shaft blank with the composite layer of gamma' -Fe 4 N and Cr 2 O 3 by rollers, and then carrying out micro-arc oxidation hole sealing and low-temperature tempering to obtain the surface-treated rear end shaft blank.
  7. 7. The highly wear-resistant air compressor crankshaft as set forth in claim 6, wherein said rear end shaft skin pretreatment process comprises: The rolling parameters of the roller are that the roller type is roller with Al 2 O 3 coating, the rolling force is 1000+/-200N, the pressing depth is 0.1-0.2mm, the feeding amount is 0.05mm/r, and the cooling mode is liquid nitrogen injection; the micro-arc oxidation parameters comprise 450 V+/-20V of voltage, 1000Hz of frequency, 30% of duty ratio, 0.5-1.5h of time and electrolyte formula (comprising Na 2 SiO 3 、KOH、CrO 3 ).
  8. 8. A highly wear resistant air compressor crankshaft as set forth in claim 1 wherein said unitary assembly of said crankshaft includes the steps of: S1, inner spline holes at two ends of the crank arm correspond to the crankshaft body, the crank arm is heated to 180-200 ℃, rapidly pressed to the crankshaft body, and tight fit is formed after cooling; s2, connecting the front end shaft with the crank arm through a taper journal, and aligning and fixing a key slot of the front end shaft with the timing mark of the crankshaft body; S3, mounting a support bearing between the rear end shaft and the crank arm, pre-coating high-temperature lubricating grease on an inner ring of the bearing, arranging a groove in the crank arm so that a connecting rod bearing can slide into the root of a shaft neck conveniently, and locking the connecting rod bearing axially to obtain an air compressor crankshaft; S4, testing the rotating speed of the air compressor crankshaft on a balancing machine, calculating the residual unbalance amount, and removing the weight by polishing the non-stressed surface of the crank arm when the residual unbalance amount exceeds the standard.
  9. 9. A highly wear resistant air compressor crankshaft prepared by the method of processing a highly wear resistant air compressor crankshaft as claimed in any one of claims 1 to 8; The high-wear-resistance air compressor crankshaft comprises a crankshaft body, wherein the crankshaft body comprises a front end shaft, a crank arm and a rear end shaft which are sequentially connected, and the front end shaft, the crank arm and the rear end shaft are subjected to surface treatment; The front end shaft forms a first composite layer on the surface layer of the front end shaft through pretreatment, and the main components of the first composite layer comprise Fe 3 O 4 、ε-Fe 2-3 N and alpha-Al 2 O 3 ; The crank arm is subjected to pretreatment to form a second composite layer on the surface layer of the crank arm, and the main components of the second composite layer comprise Fe 4 N、LaN、Fe 3 O 4 and Al 2 O 3 ; The rear end shaft forms a third composite layer on the surface layer of the rear end shaft through pretreatment, and the main components of the third composite layer comprise gamma' -Fe 4 N、Cr 2 O 3 、Fe 3 O 4 and alpha-Al 2 O 3 .
  10. 10. The highly wear resistant air compressor crankshaft of claim 9 wherein the first composite layer comprises, by weight, 30% -40% Fe 3 O 4 %, 50% -70% epsilon-Fe 2-3 N, 2% -8% alpha-Al 2 O 3 , 0% -2% Fe 4 N, 0% -2% gamma' -Fe 4 N, 0% -2% Al 2 O 3 , 0% -2% Cr 2 O 3 , 0% -2% LaN, and the balance unavoidable impurities; In the second composite layer, the weight percentage of Fe 4 N is 65-85%, the weight percentage of LaN is 2-10%, the weight percentage of Fe 3 O 4 is 10-15%, the weight percentage of Al 2 O 3 is 2-8%, the weight percentage of epsilon-Fe 2-3 N is 0-2%, the weight percentage of gamma' -Fe 4 N is 0-2%, the weight percentage of alpha-Al 2 O 3 is 0-2%, the weight percentage of Cr 2 O 3 is 0-2% and the weight percentage of the rest unavoidable impurities is the same; In the third composite layer, the weight percentage of gamma' -Fe 4 N is 40% -60%, cr 2 O 3 is 10% -30%, alpha-Al 2 O 3 is 2-8%, fe 3 O 4 is 10% -15%, fe 4 N is 0% -2%, epsilon-Fe 2-3 N is 0% -2%, al 2 O 3 is 0% -2%, laN is 0% -2% and the rest unavoidable impurities are contained.

Description

High-wear-resistance air compressor crankshaft and processing method thereof Technical Field The invention relates to the technical field of air compressor crankshaft machining, in particular to a high-wear-resistance air compressor crankshaft and a machining method thereof. Background The crankshaft on the air compressor is positioned at the connecting rod of the air compressor, and the crankshaft generates rotary motion to drive the connecting rod to make the piston generate reciprocating motion and convert the rotary motion into linear motion, and the crankshaft bears periodic complex alternating load in the working process. Among them, the processing technology of the air compressor crankshaft is critical to the quality and production efficiency of the crankshaft. At present, the crankshaft of the air compressor needs to bear periodic alternating load, common materials include 45 steel, 40Cr steel and the like, high fatigue strength and wear resistance are required, and the crankshaft is widely applied to the industrial fields of drilling equipment, natural gas compression, ship compressors and the like. The choice of suitable materials is critical to the performance and life of the crankshaft. Secondly, structural design of the crankshaft is required, and parameters such as length, diameter, shoulder width and the like of the shaft are included so as to ensure the strength and stability of the crankshaft. And finally determining the processing flow, working procedure, equipment selection and the like of the crankshaft to ensure the safety and high efficiency of the processing process of the crankshaft. Specifically, the crankshaft comprises a crankshaft body, wherein the crankshaft body comprises a front end shaft, a crank arm and a rear end shaft which are sequentially connected. The front end shaft is generally of a solid or stepped shaft structure, a key groove or threads are arranged on the surface of the front end shaft, a certain requirement on wear resistance is achieved, a crank arm is connected with a main journal and a connecting rod journal and is in a bent or branched shape, a through oil duct lubricating journal is arranged in the crank arm, high fatigue strength is needed, the tail end of the rear end shaft is a flange disc, and the rear end shaft is rigidly connected with a flywheel through a bolt and is used for transmitting power to a transmission system, so that the rear end shaft has strong biting force as a key of power output and axial positioning. The steel of the material has the characteristics of good hardenability, heat resistance, wear resistance, thermal fatigue impact toughness, thermal shock resistance and the like, and the surface treatment is carried out on the steel of each part of the crankshaft, so that the service life of the surface can be prolonged, and the core structure with excellent comprehensive performance can be reserved. Disclosure of Invention The application provides a high wear-resistant air compressor crankshaft and a processing method thereof, which aims at processing the surface layers of parts of the crankshaft, so as to improve the wear resistance of the air compressor crankshaft operating under high strength and prolong the service life of the air compressor crankshaft. The application provides a processing method of a high wear-resistant air compressor crankshaft, which is characterized by comprising the following operation steps of front end shaft surface pretreatment, crank arm surface pretreatment, rear end shaft surface pretreatment and integral assembly of the crankshaft, wherein the front end shaft surface pretreatment, the crank arm surface pretreatment and the rear end shaft surface pretreatment all comprise oxygen-nitrogen co-permeation methods, the oxygen-nitrogen co-permeation methods comprise salt baths, and the salt bath formula comprises 30% -50% of urea, 20% -40% of potassium nitrate, 10% -30% of sodium carbonate and 5% -15% of lanthanum trifluoride according to weight percentage. By adopting the technical scheme, the front end shaft, the crank arm and the rear end shaft are subjected to oxygen-nitrogen co-permeation by adopting the same salt bath formula. The process of the application utilizes geometrical differences to guide local chemical reaction paths on the basis of uniform salt bath through structure self-adaptive design and combines functional customization post-treatment to realize the accurate regulation and control of multiple effects of one dose. According to the different structures of the front end shaft, the crank arm and the rear end shaft and the different post-treatment modes, the front end shaft with high wear resistance and corrosion resistance, the crank arm with high fatigue property, the rear end shaft with high tightness and seizure resistance are formed, and the wear resistance of the air compressor crankshaft running under high strength is ensured, so that the service life of the air compressor crankshaft