Passivation solution

Abstract

The invention relates to a passivation solution. The passivation solution comprises a solvent and a solute, wherein the solvent is water; and 18.75+ / -1g of sodium hydroxide, 20.65+ / -1g of sodium phosphate, 50+ / -2g of phosphoric acid and 100+ / -4g of potassium dichromate are added into each 1,000g of water. A micro shaft made of a martensitic stainless steel material can be subjected to a salt spray test at the temperature of 35 DEG C under the condition of 5 percent sodium chloride and cannot be corroded within about 60 hours after being passivated by the passivation solution, and the passivation solution has high corrosion resistance; and in addition, a substrate cannot be subjected to hydrogen embrittlement by the passivation solution, and the passivation solution does not have any adverse effect on other performance of the substrate, so that the strength of the substrate is still kept unchanged while the corrosion resistance of the substrate is improved.

Description

technical field [0001] The invention relates to a passivation solution, in particular to a passivation solution for metal surface treatment. Background technique [0002] Passivation solution is a solution that can make the metal surface passive. Generally used for post-plating treatment of galvanized, cadmium and other coatings. The purpose is to form a surface state on the surface of the coating that can prevent the normal reaction of the metal, improve its corrosion resistance, and increase the appearance of the product. The main components of commonly used passivation solutions are chromic acid, nitric acid, and sulfuric acid. However, due to the environmental pollution caused by chromic acid, the use of low or medium concentration chromic acid passivation solution in recent years can also meet the general product requirements. In some occasions, the product requires silvery white or blue-white, and the iridescent passivation film formed after three-acid passivati...

AI Technical Summary

Problems solved by technology

[0004] The problem to be solved by the present invention is to improve the problems in the background technology that the anti-corrosion performance of the passivation solution is not enough, and it is easy to cause hydrogen embrittlement to the substrate.