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CN-122007343-A - Strengthening and baking method for fan casting sand mould

CN122007343ACN 122007343 ACN122007343 ACN 122007343ACN-122007343-A

Abstract

The invention discloses a strengthening and baking method of a fan casting sand mould, which relates to the technical field of fan casting and comprises the following steps of S1, sand mould preparation, S2, paint preparation, S3, surface flow coating, S4, ignition and spontaneous combustion, wherein the sand, resin and curing agent are mixed according to the mass ratio of 1:0.01:0.005 to obtain a sand mould matrix, the high-temperature-resistant fire-resistant paint is mixed with industrial alcohol to be prepared into slurry suitable for flow coating, the slurry is flow coated on the surface of the sand mould matrix to form a uniform coating, and the slurry on the surface of the flow coated sand mould is ignited. According to the invention, through a synergistic dehydration mechanism combining ignition spontaneous combustion and staged baking, most of the surface and shallow solvent are rapidly removed by alcohol spontaneous combustion, and deep bound water is thoroughly and stably removed by a mild baking strategy of low temperature and high temperature, so that the sand mould is ensured to be in an absolute dry state before casting, and the risk of explosion caused by instantaneous expansion of water vapor is eliminated.

Inventors

  • YANG ZHIDE
  • ZHANG BUQING
  • ZHU GUOXIANG
  • XU XINRONG

Assignees

  • 安徽涌诚机械有限公司

Dates

Publication Date
20260512
Application Date
20251031

Claims (8)

  1. 1. The strengthening and baking method of the fan casting sand mould is characterized by comprising the following steps of: S1, preparing a sand mould, namely mixing sand, resin and a curing agent according to the mass ratio of 1:0.01:0.005, and naturally reacting and forming to obtain a sand mould matrix; s2, preparing a coating, namely mixing the high-temperature-resistant refractory coating with industrial alcohol to prepare slurry suitable for flow coating; s3, surface flow coating, namely, flow coating the slurry on the surface of the sand mould matrix to form a uniform coating; S4, igniting and spontaneous combustion, namely igniting the slurry on the surface of the sand mould after flow coating, and carrying out primary solidification and drying on the coating by utilizing spontaneous combustion of industrial alcohol; s5, baking in stages, namely sending the sand mould subjected to ignition and spontaneous combustion treatment into baking equipment, and sequentially carrying out low-temperature baking and high-temperature curing.
  2. 2. The method for strengthening and baking a sand mold for a fan casting according to claim 1, wherein in the step S2, the mass ratio of the high temperature resistant refractory coating to the industrial alcohol is 1:0.4.
  3. 3. The method for strengthening and baking a sand mold for fan casting according to claim 2, wherein in step S2, the high temperature-resistant refractory coating is ISOPENG-1600 sulfur-penetration-resistant coating, and the flow coating working baume is adjusted to 20-50 be by adding the industrial alcohol.
  4. 4. The method for strengthening and baking a sand mold for casting a fan according to claim 3, wherein the ISOPENG-1600 sulfur penetration-resistant paint has a density of 1.4-1.7g/cm3 and comprises, by mass, 22% of carbon, 28% of magnesium oxide and 15% of silicon.
  5. 5. The method for strengthening and baking a sand mold for fan casting according to claim 1, wherein in step S4, the ignition spontaneous combustion period is 1 to 3 minutes.
  6. 6. The method for strengthening and baking a sand mold for fan casting according to claim 1, wherein in step S5, specific parameters of the staged baking are: the low-temperature baking temperature is 80-120 ℃ and the baking time is 30-60 minutes; The high-temperature curing temperature is 180-220 ℃ and the baking time is 60-120 minutes.
  7. 7. The method for strengthening and baking a sand mold for a fan casting according to claim 6, wherein a rate of temperature rise from room temperature to a target temperature is controlled to be within 20 ℃ per hour in the low-temperature baking stage.
  8. 8. The method of claim 6, wherein after the high temperature solidification stage is completed, the sand mold is cooled to 80 ℃ or less in the baking equipment and is discharged.

Description

Strengthening and baking method for fan casting sand mould Technical Field The invention relates to the technical field of fan casting, in particular to a method for strengthening and baking a sand mould for fan casting. Background In the casting production process of fan castings, the preparation and treatment of sand molds are key links related to casting quality and production safety. At present, a sand mould is generally manufactured by adopting a resin sand process, and fireproof paint is coated on the surface of the sand mould in a spraying manner so as to improve the surface quality and resist the molten iron scouring. The traditional sand mold baking process mainly relies on kiln or hot air convection to perform long-time heating and drying, and aims to remove paint solvent and moisture. However, the single hot baking mode has the obvious defects that firstly, if the baking is insufficient, the solvent or the moisture remained in the deep layer of the sand mould can be instantaneously vaporized when contacting high-temperature molten iron, so that huge pressure is generated, the sand mould is burst to cause safety and quality accidents, secondly, the surface of the coating is difficult to be effectively reinforced by pure hot air drying, the hardness and the roughness of the surface of the sand mould are insufficient, and the defects of sand washing, sand burning and the like are easily generated in the casting process, so that the casting precision is influenced. In addition, the whole process depends on an external heat source, so that the energy consumption is high, the production period is long, and the efficiency is low. Although attempts have been made in the industry to improve the above problems by adjusting the paint formulation or extending the baking time, the technical limitations of single thermal energy driven and dehydration and strengthening separation have not been fundamentally broken through. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a method for strengthening and baking a sand mould for casting a fan. In order to achieve the purpose, the technical scheme of the invention is as follows, the strengthening and baking method of the fan casting sand mould comprises the following steps: S1, preparing a sand mould, namely mixing sand, resin and a curing agent according to the mass ratio of 1:0.01:0.005, and naturally reacting and forming to obtain a sand mould matrix; s2, preparing a coating, namely mixing the high-temperature-resistant refractory coating with industrial alcohol to prepare slurry suitable for flow coating; s3, surface flow coating, namely, flow coating the slurry on the surface of the sand mould matrix to form a uniform coating; S4, igniting and spontaneous combustion, namely igniting the slurry on the surface of the sand mould after flow coating, and carrying out primary solidification and drying on the coating by utilizing spontaneous combustion of industrial alcohol; s5, baking in stages, namely sending the sand mould subjected to ignition and spontaneous combustion treatment into baking equipment, and sequentially carrying out low-temperature baking and high-temperature curing. Preferably, in the step S2, the mass ratio of the high temperature resistant refractory coating to the industrial alcohol is 1:0.4. Preferably, in step S2, the high temperature resistant refractory coating is ISOPENG-1600 sulfur penetration resistant coating, and its flow coating working baume is adjusted to 20-50 be by adding the industrial alcohol. Preferably, the ISOPENG-1600 sulfur penetration resistant paint has a density of 1.4-1.7g/cm 3, and comprises the main components of 22% of carbon, 28% of magnesium oxide and 15% of silicon in percentage by mass. Preferably, in step S4, the ignition self-ignition period is 1 to 3 minutes. Preferably, in step S5, specific parameters of the staged baking are: the low-temperature baking temperature is 80-120 ℃ and the baking time is 30-60 minutes; The high-temperature curing temperature is 180-220 ℃ and the baking time is 60-120 minutes. Preferably, in the low-temperature baking stage, the rate of temperature rise from room temperature to the target temperature is controlled within 20 ℃ per hour. Preferably, after the high temperature solidification stage is completed, the sand mould is cooled to below 80 ℃ along with the furnace in the baking equipment and then is discharged from the furnace. Compared with the prior art, the invention has the beneficial effects that: 1. according to the invention, through a synergistic dehydration mechanism combining ignition spontaneous combustion and staged baking, most of the surface and shallow solvent are removed rapidly by alcohol spontaneous combustion, and deep bound water is thoroughly and stably removed by a mild baking strategy of low temperature and high temperature, so that the sand mould is ensured to be in an absolute dry state before casting, and