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CN-121820537-B - Resin sand casting method of axle housing casting

CN121820537BCN 121820537 BCN121820537 BCN 121820537BCN-121820537-B

Abstract

The invention provides a resin sand casting method of axle housing castings, which belongs to the technical field of casting, and comprises the steps of casting and process design, mould and sand core manufacture, mold closing and pouring preparation, smelting and pouring, cooling, shakeout and cleaning, heat treatment and finishing, and used sand regeneration. The casting resin sand comprises water-washed quartz sand, biomass modified furan resin, HTAM high-temperature-resistant migration-resistant modifier, p-toluenesulfonic acid, aluminum dihydrogen phosphate, lactic acid, ammonium bicarbonate, polystyrene, expandable graphite, silane coupling agent, mica powder, calcined kaolin and diabase powder. The biomass modified furan resin is prepared by reacting furfuryl alcohol, bio-based polyol, urea, phenol and p-toluenesulfonic acid and adding KH-550. HTAM the high temperature resistant and migration resistant modifier is prepared by the reaction of KH-570 modified activated ceramic microbeads, pyromellitic dianhydride and 4,4' -diaminodiphenyl ether and heat treatment.

Inventors

  • PAN TIANYONG
  • ZHOU XIAOWEI
  • E LIMING
  • JIANG HONGBIN
  • Xu Baocong

Assignees

  • 丹东金田机械有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (9)

  1. 1. The resin sand casting method of the axle housing casting is characterized by comprising the following steps of: Designing pouring positions and parting surfaces of castings, selecting bottom pouring, setting a riser, preparing a plurality of sand cores with tensile strength of more than 1.2MPa and collapsibility index of more than 95% after the room temperature tensile strength is more than 2.8MPa and the 800 ℃ high temperature is 10min, bonding and assembling the sand cores, coating refractory coating, drying, combining a lower box, the sand cores and an upper box, fastening the box, placing a pouring cup and a pouring ring, pouring casting liquid, cooling to below 500 ℃ in a casting mold, vibrating and removing sand sticking and flash burrs on the surfaces of the castings, and obtaining casting blanks; the sand core is prepared from casting resin sand, wherein the casting resin sand comprises, by mass, 100 parts of water-washed quartz sand, 1.5 parts to 2 parts of biomass modified furan resin, 1.2 parts to 1.8 parts of HTAM high-temperature-resistant migration-resistant modifier, 0.4 part to 0.6 part of composite curing agent, 0.5 part to 1.0 part of gradient dispersing agent, 0.1 part to 0.2 part of silane coupling agent, 0.2 part to 0.3 part of cracking resistance auxiliary agent and 1.5 part to 2.5 parts of high-temperature-resistant reinforcing phase, the composite curing agent comprises p-toluenesulfonic acid, aluminum dihydrogen phosphate and lactic acid, the gradient dispersing agent comprises ammonium bicarbonate, polystyrene and expandable graphite, the cracking resistance auxiliary agent is mica powder, and the high-temperature-resistant reinforcing phase comprises calcined kaolin and lithium-bright stone powder; The biomass modified furan resin is prepared by stirring furfuryl alcohol, bio-based polyol, urea and deionized water, adding phenol and p-toluenesulfonic acid for polycondensation reaction, adjusting pH to 4.0-4.5, diluting with deionized water, adding KH-550, stirring, and adjusting the solid content to 75-80 wt%; the HTAM high-temperature-resistant migration-resistant modifier is prepared by dispersing activated ceramic microbeads modified by KH-570 into N-methylpyrrolidone, adding pyromellitic dianhydride and 4,4' -diaminodiphenyl ether, stirring for reaction, carrying out filter pressing, sequentially carrying out heat treatment on filter cakes at 100-110 ℃, 150-160 ℃ and 200-220 ℃ and cooling to room temperature, and then scattering and sieving.
  2. 2. The method for casting resin sand for axle housing castings according to claim 1, wherein casting resin sand generated by vibration shakeout is collected, crushed, winnowed and magnetically separated, and roasted for 1.5-2 hours at 550-650 ℃ and subjected to granularity adjustment, so that reclaimed sand is obtained, and the reclaimed sand rate is more than 80 wt%.
  3. 3. The resin sand casting method of the axle housing casting is characterized in that the granularity of the water-washed quartz sand is 40-70 meshes, and the composite curing agent comprises 60-65wt% of p-toluenesulfonic acid aqueous solution, 45-50wt% of aluminum dihydrogen phosphate aqueous solution and 85-90wt% of lactic acid aqueous solution in a mass ratio of (70-75) (25-30) (3-5).
  4. 4. The resin sand casting method of the axle housing casting is characterized in that the gradient dispersant comprises ammonium bicarbonate, polystyrene microspheres and expandable graphite in a mass ratio of (1-1.2) (0.5-0.7) (0.8-1), the silane coupling agent is KH-550 or KH-560, and the high-temperature resistant reinforcing phase comprises calcined kaolin and lithium-ion powder in a mass ratio of (2-2.5) (1-1.2).
  5. 5. The resin sand casting method of the axle housing casting is characterized by comprising the steps of stirring and dissolving 60-70 parts of furfuryl alcohol, 15-25 parts of bio-based polyol, 5-10 parts of urea and 3-5 parts of deionized water, adding 2-5 parts of phenol and 0.5-1.5 parts of p-toluenesulfonic acid, stirring and polycondensing, adjusting pH to 4.0-4.5, adding 2-4 parts of deionized water for dilution, adding 0.3-0.8 part of KH-550 for stirring, adjusting solid content to 75-80 wt% with deionized water at room temperature, and filtering to obtain the biomass modified furan resin.
  6. 6. The method for casting resin sand for axle housing castings, which is characterized in that the bio-based polyol is polytrimethylene ether glycol with a number average molecular weight of 500g/mol, the stirring and dissolving temperature is 60-65 ℃, the stirring and polycondensation reaction is 80-85 ℃ and stirring and polycondensation reaction is 90-120 min, the pH is adjusted by 5-8 wt% of sodium carbonate aqueous solution, the temperature is reduced to 40-50 ℃ after the pH is adjusted, and the filtration is carried out through a 100-150-mesh sieve.
  7. 7. The method for casting resin sand for axle housing castings, which is characterized in that the preparation method of the HTAM high-temperature-resistant migration-resistant modifier comprises the steps of dispersing activated ceramic microbeads modified by KH-570 into 70-80 parts of N-methylpyrrolidone under the protection of nitrogen, stirring at a temperature below 15 ℃, dropwise adding 20-22 parts of NMP solution of pyromellitic dianhydride, adding 20-23 parts of 4,4' -diaminodiphenyl ether, stirring for reaction, press-filtering, and sequentially carrying out heat treatment on filter cakes at 100-110 ℃, 150-160 ℃ and 200-220 ℃, cooling to room temperature, scattering and sieving to obtain the HTAM high-temperature-resistant migration-resistant modifier.
  8. 8. The method for casting resin sand for axle housing castings, which is characterized by comprising the steps of adding 30-35 parts of hollow closed-cell hollow ceramic microbeads into 60-70 parts of ethanol aqueous solution, stirring and dispersing, adding 3-4 parts of KH-570, adjusting the pH to 3.5-4.5,50 ℃ and reacting for 3-4 hours at 55 ℃, carrying out suction filtration, washing a filter cake with ethanol, and carrying out vacuum drying to obtain the activated ceramic microbeads.
  9. 9. The resin sand casting method of the axle housing casting is characterized in that the concentration of NMP solution of pyromellitic dianhydride is 40-45 wt%, stirring reaction is carried out for 5-6 h at 15-20 ℃, heat treatment is carried out for 1-1.5 h at 100-110 ℃, heat treatment is carried out for 1-1.5 h at 150-160 ℃, heat treatment is carried out for 1.5h at 200-220 ℃, and the mesh number of the sieving is 100-150 mesh.

Description

Resin sand casting method of axle housing casting Technical Field The invention belongs to the technical field of casting, and particularly relates to a resin sand casting method of an axle housing casting. Background The axle housing is used as a core bearing component of the automobile chassis, and needs to bear alternating load, impact vibration and complex stress in the running process of the automobile, and the casting quality directly determines the running safety of the whole automobile and the durability of the chassis. The traditional axle housing casting adopts a clay sand molding process mostly, the process has the defects of low raw material cost and wide applicability, but the process has the defects of poor sand collapsibility, high casting surface roughness, low dimensional accuracy and the like, the casting is easy to have casting defects such as sand inclusion, air holes, shrinkage porosity and the like, a large number of cutting processing procedures are needed subsequently, the material utilization rate is only 60% -70%, and the light weight and high-precision manufacturing requirement of the high-end commercial vehicle axle housing is difficult to meet. With the improvement of the quality requirements of the automobile industry on castings, the resin sand casting technology gradually replaces the clay sand technology, and becomes a main stream forming method of axle housing castings. The resin sand takes furan resin, phenolic resin and the like as binders, and achieves molding sand hardening through a curing agent-induced crosslinking reaction, and has the advantages of high molding sand strength, good collapsibility, high casting size precision, good surface finish and the like, and can greatly reduce machining allowance and improve the material utilization rate to more than 85%. Meanwhile, the resin sand molding can realize mechanized and automatic production, and is suitable for the manufacturing requirements of axle housing castings in various and large batches. However, the existing resin sand casting method still has the technical bottlenecks that on one hand, formaldehyde, phenols and other harmful gases are released in the traditional furan resin sand curing process, the operation environment is bad, and on the other hand, the high-temperature deformation resistance of the resin sand is insufficient, thick and large parts of the axle shell casting, such as axle shell flanges and shaft heads, are easy to cause wall migration in the casting process, so that shrinkage cavity and shrinkage porosity of the casting are caused, riser feeding is additionally arranged, and the process complexity and the production cost are increased. In addition, the collapsibility of the conventional resin sand is obvious in attenuation at high temperature, the casting cleaning difficulty is high, the waste sand recycling rate is only 50% -60%, and the problem of resource waste is outstanding. At present, the trend of automobile weight reduction promotes axle housing castings to develop towards thinning and complicating directions, and higher requirements are put forward on the high-temperature performance, environmental friendliness and reproducibility of resin sand. Therefore, the casting process and the matched resin sand of the axle housing casting are required to be developed, and the manufacturing requirements of high quality and low cost of the axle housing casting are met. Disclosure of Invention The method aims at solving the problems that the thick and large part of the casting is easy to have wall migration in the casting process, so that the shrinkage cavity and shrinkage porosity of the casting are caused, the collapsibility is obvious in attenuation at high temperature, and the cleaning difficulty of the casting is high in the existing resin sand casting of the axle housing casting. The invention provides a method for casting resin sand of axle housing castings, which systematically solves the bottlenecks of poor high-temperature deformation resistance, collapse property attenuation, low regeneration rate and the like of traditional resin sand through the cooperative optimization of a bonding system, functional additives and a process, realizes the cooperation of normal temperature and high temperature strength, balanced migration resistance and collapse property, and well guarantees the environmental protection regeneration and the casting quality of the resin sand. The specific technical scheme is as follows: a resin sand casting method of axle housing castings comprises the following steps: Designing pouring positions and parting surfaces of castings, selecting bottom pouring, setting a riser, preparing a plurality of sand cores with tensile strength of more than 1.2MPa and collapsibility index of more than 95% after the room temperature tensile strength is more than 2.8MPa and the 800 ℃ high temperature is 10min, bonding and assembling the sand cores, coating refractory coating, drying,