Steel normal-temperature blackening solution composite film-forming accelerator, steel normal-temperature blackening solution and preparation method of steel normal-temperature blackening solution

Abstract

The invention discloses a steel normal-temperature blackening solution composite film-forming accelerator which comprises the following components in parts by weight: 1-3 parts of calcium nitrate, 4-8 parts of cobalt nitrate, 2.5-5 parts of sodium borate and 0.3-0.6 part of metanitrobenzene sulfonic acid. The adhesive force and corrosion resistance of a blackening film are obviously improved, and the film-forming speed is also increased. The invention also discloses a steel normal-temperature blackening solution. The steel normal-temperature blackening solution takes water as a solvent, has a pH value of 2-3 and comprises the main components of 2-8 g / L copper sulfate, 3-6.5 g / L selenium dioxide, 2-10 g / L potassium dihydrogen phosphate, 2-6 g / L zinc nitrate, 1-3 g / L nickel sulfate, 2-6 g / L composite film-forming accelerator, 3-8 g / L urea and 0.5-8 g / L complexing agent. The invention also discloses a preparation method of the steel normal-temperature blackening solution. The blackening film of the prepared blackening solution has firm adhesive force, high corrosion resistance and less sediment.

Description

Technical field [0001] The invention belongs to the field of metal surface chemical treatment, and specifically relates to a composite film-forming accelerator of a steel normal temperature blackening liquid, a steel normal temperature blackening liquid and a preparation method of the steel normal temperature blackening liquid. Background technique [0002] Steel blackening technology is mainly used for anti-corrosion and appearance decoration of steel workpieces. The blackening process can be divided into two categories, one is the traditional high-temperature blackening process, and the other is the new room-temperature blackening process. Since the invention of steel room temperature blackening technology by American engineers in the early 1980s, room temperature blackening technology has attracted widespread attention from society due to its outstanding advantages such as energy saving, environmental protection, and high efficiency compared with traditional high-temperat...

AI Technical Summary

Problems solved by technology

One of the important factors is that the current room temperature blackening technology is immature, and there is no good film-forming accelerator. Except for a very small number of blackening formulas that can produce products with better film-forming quality, most of the existing The blackening effect of disclosed blackening liquid formula is all unsatisfactory, and its common defect is:

[0006] The generation of precipitation will inevitably consume the added active ingredient selenium dioxide, reducing the efficiency

[0007] 2. There is still an insurmountable defect in the existing room temperature blackening products, which is that the operating time range is strictly limited. If the blackening time is a little longer, a large amount of floating black will appear in the blackening film, and it will even be loose and scrapped

This is because the blackening film is not fine enough and the adhesion is poor. The blackening liquid can penetrate the formed film and continue to react with the metal substrate, causing the film layer to be destroyed.

[0008] 3. Poor corrosion resistance. At present, the salt spray test of workpieces treated by the normal temperature blackening process is difficult to exceed 5 hours

[0009] 4. The adhesion of the blackened film is not firm: for several similar blackened products sold in the market, it is difficult to rub the surface of the blackened workpiece with experimental filter paper reciprocatingly, and its wear resistance is difficult to exceed 100 times