Stainless steel rust how to remove rust?

Stainless steel rust how to remove rust?

# Rust removal # Industrial rust removal is to remove oxides and rust spots on the metal surface. Common is mechanical rust and chemical rust, chemical industry rust, also known as pickling rust removal, is the use of pickling liquid, acid rust remover to reduce the metal surface of metal oxides through chemical reaction to metal atoms, reducing the probability of continuous oxidation of metal rust.

01
What acid is used for industrial rust removal?
Sulfuric acid: itself is a kind of strong oxidation, pickling and rust removal need to dilute a certain proportion of concentrated sulfuric acid. Sulfuric acid is mainly used to remove metal rust by mechanical stripping.
Note: Industrial rust removal with sulfuric acid is easy to lead to "over-corrosion" of the iron matrix of the steel workpiece, increasing the possibility of "hydrogen embrittleness", the need for heating operation, iron salt is not easy to thoroughly wash off, and concentrated sulfuric acid is easy to cause personal injury.
② Hydrochloric acid: mainly depends on the dissolution of the oxide on the metal surface to remove. It is easy to operate at room temperature, has small corrosion on the iron surface, bright surface of the workpiece, less hydrogen absorbed by the steel, and easy to wash off the iron salt on the surface.
Note: The utilization of waste acid is difficult, the price is high, the precipitation of asphyxiating gas, and the utilization efficiency of pickling solution is low.
(3) Nitric acid: When in contact with the metal, the surface of these metals can be rapidly oxidized, resulting in a dense oxide film, and the internal metal will no longer be corroded, playing a passivation protection role.
Note: Nitric acid is a pungent odor of volatile acid, strong corrosive, chemical reaction with steel can produce harmful gas - nitrogen. Easy environmental protection not pass.
Phosphoric acid: phosphoric acid is a medium strength acid, suitable for welding parts, components before painting rust removal.
Note: The rust removal capacity of phosphoric acid is low, so the rust removal of phosphoric acid solution generally requires heating.
Organic acids: organic acids for industrial rust removal are also carried out by pickling and rust removal principle, which is easier to meet environmental requirements than inorganic acids. Recommended vci-708 environmental protection rust removal agent, compound organic acid composition, will not cause "hydrogen embrittle" phenomenon, compound environmental requirements, no irritating odor.

02
What is used for industrial rust removal?
Industrial derusting can be carried out according to the desired derusting effect and the choice of derusting process.
① Organic acid rust remover is recommended for pickling metal parts, steel plates and coils.
② For industrial rust removal that needs to achieve the dual effect of rust removal and corrosion prevention, such as large I-beams, steel, color steel tiles, steel pipes, etc., rust conversion agent is recommended to convert rust into anti-corrosion layer, which can be corroded for 10 years under the theory.
③ For industrial rust removal of precision parts, it is recommended that neutral rust remover, PH 7, will not cause any adverse effects on the metal surface.