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CN-121976178-A - Method for removing rust or red ash of steel part chemical oxide film

CN121976178ACN 121976178 ACN121976178 ACN 121976178ACN-121976178-A

Abstract

The invention belongs to the technical field of metal surface treatment, and particularly relates to a method for removing rust or red ash of a steel part chemical oxide film. In order to remove rust or red ash on the surface of a steel part chemical oxide film, the invention carries out oxidation post-treatment after chemical oxidation, wherein the main components of post-treatment liquid comprise a reducing agent, a complexing agent and a surfactant, the reducing agent comprises sodium gluconate, potassium sodium tartrate and sodium ascorbate, the complexing agent comprises amino trimethylene phosphonic acid, disodium ethylene diamine tetraacetate and sodium citrate, the surfactant comprises AEO-7, AEO-9, fatty alcohol ether phosphate potassium salt and alkyl glycoside, and a small amount of sodium metasilicate can be added. Can effectively remove rust and ash on the surface of the chemical oxide film, the oxide film has no peeling and blackening phenomena, and the uniform luster is maintained.

Inventors

  • YU SIYUAN
  • WEI JIAO
  • LIU TING
  • ZHU YANAN
  • CHEN YUCONG
  • LIU JIAOYANG
  • LI WEI
  • SHI XIAOTONG

Assignees

  • 沈阳瑞特热表动力科技有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (9)

  1. 1. A method for removing rust or red ash of a steel part by chemical oxidation film is characterized by comprising the following steps of carrying out oxidation post-treatment after the chemical oxidation treatment of the steel part to remove rust or red ash of the chemical oxidation film, wherein the main components of post-treatment liquid adopted by the oxidation post-treatment comprise a reducing agent, a complexing agent and a surfactant; The reducing agent is an organic reducing agent, the complexing agent is a chelating complexing agent containing nitrogen or phosphorus, and the surfactant is at least one of an anionic surfactant containing phosphorus or nitrogen and a nonionic surfactant.
  2. 2. The method for removing rust or red hanging ash from a steel part chemical oxide film according to claim 1, wherein the mass ratio of the reducing agent to the complexing agent to the surfactant is 40:20:20, and the total concentration of the reducing agent, the complexing agent and the surfactant in the post-treatment liquid is 15g/L-25g/L.
  3. 3. The method for removing rust or red ash on a steel part chemical oxide film according to claim 1, wherein the reducing agent comprises sodium gluconate, potassium sodium tartrate and sodium ascorbate, the complexing agent comprises aminotrimethylene phosphonic acid, disodium ethylenediamine tetraacetate and sodium citrate, and the surfactant comprises AEO-7, AEO-9, fatty alcohol ether phosphate potassium salt and alkyl glycoside.
  4. 4. The method for removing rust or red hanging ash from a chemical oxide film of a steel part according to claim 3, wherein the reducing agent comprises 60% by mass of sodium gluconate, 30% by mass of sodium potassium tartrate and 10% by mass of sodium ascorbate.
  5. 5. The method for removing rust or red ash on a steel part chemical oxide film according to claim 3, wherein the complexing agent comprises 50% of amino trimethylene phosphonic acid, 30% of disodium edetate and 20% of sodium citrate.
  6. 6. The method for removing rust or red ash of a steel part chemical oxide film according to claim 3, wherein the surfactant comprises 40% by mass of AEO-7, 30% by mass of AEO-9, 20% by mass of fatty alcohol ether phosphate potassium salt and 10% by mass of alkyl glycoside.
  7. 7. The method for removing rust or red ash from a steel part by using a chemical oxide film according to claim 1, wherein the post-treatment liquid further comprises sodium metasilicate, and the dosage of the sodium metasilicate is 5g/L-15g/L.
  8. 8. The method for removing rust or red ash from a steel part by chemical oxidation film according to claim 1, wherein the pH of the post-treatment liquid is more than 7, the treatment temperature of the oxidation post-treatment is 50-75 ℃, and the treatment time is 5-10 min.
  9. 9. The method for removing rust or red ash from a steel part by using a chemical oxide film according to claim 1, wherein the concentration of iron ions in the post-treatment liquid is less than or equal to 500mg/L.

Description

Method for removing rust or red ash of steel part chemical oxide film Technical Field The invention belongs to the technical field of metal surface treatment, and particularly relates to a method for removing rust or red ash of a steel part chemical oxide film. Background The surface of a steel part (such as bearing steel, stainless steel, heat-resistant steel and the like) of a military aircraft engine usually needs a chemical oxide film so as to realize surface protection with low cost, high precision and high compatibility under the extreme working conditions of high-temperature friction, fuel oil/lubricating oil corrosion, salt spray corrosion and alternating stress, and meet the combat readiness requirements of the military aircraft with high reliability, long service life and low maintenance. The chemical oxide film on the surface of the steel part is uniformly dark blue-black, blue-black or black, and the main component of the chemical oxide film of the steel part is magnetic ferric oxide (ferroferric oxide), but in the process of generating a film layer, the impermissible defects such as surface rust or red ash hanging are easy to generate due to overlong exposure time of carbon steel parts in air or when the bath solution is in a critical state. The corrosion on the surface (the red rust Fe 2O3 is formed by oxidation reaction of matrix iron) can form corrosion channels in time to cause cracking and skinning of a film layer, continuous corrosion can cause pitting corrosion of precise components such as bearing raceways, gear tooth surfaces and the like, the fatigue strength of a transmission system is reduced, the fatigue life is shortened, and even cracks and fractures are initiated to directly cause the failure of the transmission system of an engine. The attachment of red ash (Fe 3+ deposited or loosened Fe 2O3 in residual groove liquid) to the surface can increase the friction coefficient of motion of bearings, gears and the like, increase part wear, reduce part life, reduce engine efficiency and even cause jamming risks. The surface rust or red hanging ash is mainly removed through the acid corrosion (HCl+if T) in the pretreatment process at present, namely, the film removal and reoxidation process is needed after the part runs through all the processes, and the protective film layer spontaneously formed on the surface of the part can be corroded while the hanging ash and the rust are removed by the repaired part, so that the phenomenon of part light loss can occur due to redeposition of the oxide film layer after repair, the process cost is increased, the processing efficiency is reduced, and the film quality of the repaired part is poorer. Therefore, the method which can timely remove rust or red ash on the surface of the deposited oxide film layer in the process and can not damage the protective film layer of the part is researched, so that the deposited oxide film layer has good quality and can achieve the purposes of reducing cost and enhancing efficiency. Disclosure of Invention Aiming at the problems, the invention provides a method for removing rust or red ash of a steel part chemical oxide film. The conventional process of the oxide film on the surface of the part comprises the following steps of part hanging, chemical degreasing, hot water washing, cold water washing, corrosion, cold water washing, neutralization, chemical oxidation, protective packaging and delivery. The scheme of the invention mainly adds an oxidation post-treatment process after the main process of the chemical oxidation of the steel part, and the main process comprises the steps of part hanging, chemical degreasing, hot water washing, cold water washing, corrosion, cold water washing, neutralization, chemical oxidation, oxidation post-treatment, protection packaging and delivery. The steel part is subjected to oxidation post-treatment after being subjected to chemical oxidation treatment so as to remove rust or red ash, wherein post-treatment liquid adopted in the oxidation post-treatment process is alkaline, and the main components comprise a reducing agent A, a complexing agent B and a surfactant C in a mass ratio of 40:20:20, wherein the total concentration of the reducing agent A, the complexing agent B and the surfactant C in the post-treatment liquid is 15g/L-25g/L; The reducing agent A is an organic reducing agent and comprises sodium gluconate, potassium sodium tartrate and sodium ascorbate, wherein in the reducing agent A, the mass of the sodium gluconate accounts for 60%, the mass of the potassium sodium tartrate accounts for 30%, and the mass of the sodium ascorbate accounts for 10%; The complexing agent B is a weak chelating complexing agent containing nitrogen or phosphorus and comprises aminotrimethylene phosphonic Acid (ATMP), disodium ethylenediamine tetraacetate (EDTA-2 Na) and sodium citrate, wherein in the complexing agent B, the mass of the aminotrimethylene phosphonic acid accounts for 50%, th