Hard chromium plating method and solution formula for piston rod class parts

Abstract

The invention belongs to the field of chemical engineering and particularly relates to a hard chromium plating method and solution formula for piston rod class parts. The objective is to solve the problem that when a piston rod is produced, the quality of a hard chromium coating produced by a traditional electric chromium plating technology is not ideal, and the current efficiency is low. The method comprises the following steps: first, removing oil; then, washing, drying and carrying out insulation protection; after washing, carrying out weak corrosion; washing, and then, plating hard chromium; after washing, carrying out backflow bleaching, after neutralization, washing and drying; and after removing hydrogen, carrying out test. The hard chromium plating solution formula comprises 200-225g/L of CrO3, 2.3-2.5g/L of H2SO4 and 3-6g/L of Cr3+. The hard chromium plating method and solution formula are more suitable for piston rod class parts, particularly the production of hard chromium films of 30GrMnSiA materials. Moreover, the CrO3 content in the formula is reduced, so that the cost is reduced, and environmental pollution is reduced.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a hard chromium plating method and solution formula for piston rod parts. Background technique [0002] At present, all the servo mechanisms of the carrier series and weapon series include piston rod parts, and the material is 30GrMnSiA. Due to the design performance of the parts, the piston rod is required to be partially electroplated with hard chromium. [0003] In the traditional electrochrome plating process, the electroplating solution is based on chromic acid and sulfuric acid is used as the catalyst. The ratio of the two is 100:1. The advantages of the process are that the plating solution is stable and easy to operate; The quality of the coating is relatively high, with the advantages of brightness, wear resistance, stability, etc., so it has been widely used. However, the cathodic current efficiency of this solution formula is very low, generally only 8% to...

AI Technical Summary

Problems solved by technology

However, the cathodic current efficiency of this solution formula is very low, generally only 8% to 16%, and consumes a lot of energy. Moreover, the concentration of chromic acid is high, the pollution of chromium-containing wastewater and waste gas is large, the waste of materials is serious, the temperature of the plating solution is high, and the waste of energy is large. Therefore, the electroplating industry at home and abroad has been committed to reforming the traditional high-chromium chromium plating process. Extensive research and exploration have been carried out in order to reduce the concentration of chromic acid, reduce its hazards, and improve the efficiency of chromium plating.

To improve the traditional chromium plating process, the method of adding additives to the chromic acid plating solution is generally adopted. At present, there are several prominent processes, one uses fluoride as a catalyst, and the other uses chlorine, bromine, iodine and stable carboxyl Acid is used as a catalyst, and there is also a chromium plating process using rare earth as an additive, but fluoride has certain pollution, which is not good for the environment, and the cost of rare earth is relatively high

[0004] When producing piston rods, the quality of the hard chromium plating produced by the traditional electrochrome plating process is not ideal (the film layer is rough), and the current efficiency is low, which is related to the cylindrical structure and material of the piston rod. For this problem, it is urgent to provide a hard chromium plating method and solution formula for piston rod parts, so that it is more suitable for the production of piston rod parts and improves the quality of the film layer

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