Stainless steel surface treatment of a new era, pickling, passivation two-in-one!

original title: stainless steel surface treatment of a new era, pickling, passivation two-in-one!Stainless steel pickle passivation cream
is a chemical agent for the removal of yellow, blue, black welding spots and oxide skins produced by stainless steel welding and high-temperature processing,
is suitable for ferrogenics, austere and other stainless steel
. The stainless steel comprehensive acid washing passivation, the formation of a complete passivation film, can effectively improve its corrosion resistance, so that the stainless steel surface bright as new, excellent effect, in the process of acid washing passivation can simultaneously remove the surface of the work piece of oil, rust spots, welding spots, oxide layer, free iron and other dirt, after treatment of the surface into uniform silver. Today we will detail the principle of stainless steel surface treatment acid wash passivation and the common components of stainless steel picker passivation paste - 1, stainless steel surface treatment acid wash passivation principlepassivation
refers to the metal oxidizing medium treatment, its corrosion rate than before the original treatment has a significant decrease in the phenomenon, called metal passivation.Passivation
can mainly be explained by thin film theory, that is, passivation is considered to be
cause of metal and oxidizing medium
,
in the metal surface treatment to produce a very thin, dense, well-covered, can be firmly attached to the metal surface of the passivation film
. This film exists as a separate phase, usually a compound of oxygen and metal. It acts as a completely separate metal from the corrosion medium, preventing the metal from contacting the corrosion medium directly, thus basically stopping the metal from dissolving.Orthal stainless steel
after oxidizing media treatment, its surface can form to meet the above requirements of the
passivation film
, but the passivation film
in the active role of Cl-, Br-, F-and other halogen ions under the action of
,
is highly vulnerable to destruction
. This is one of the reasons why the Australtalic stainless steel pressure vessel, which has been acid-washed and passivated, cannot remove water stains after a water pressure test, but should control the Cl-content of the water not exceeding 25 ppm.the oxidation film of not any metal can be regarded as a passivation film, e.g. the oxide film formed by
carbon steel after high temperature oxidation cannot be used as a passivation film
because it cannot meet the requirements of firmly attaching to the metal surface. For Austereo stainless steel generally using oxidizing solution with nitric acid as the main agent to treat, in order to ensure the effect of passivation treatment, before passivation of the passivated surface for pickring treatment. The whole process is called pick wash passivation treatment, referred to as pick wash passivation.2. The common components of stainless steel acid wash passivation cream 1, corrosion agentcorrosion agents are generally used as acidic substances
, often used hydrofluoric acid, dilute hydrochloric acid, nitric acid or other types of acidic substances, fluoride, etc.
The main role
is
cleaning stains on stainless steel surfaces and oxide film
, nitric acid solution is used alone to remove free iron and other metal stains is effective, but for the removal of iron oxide skin, thick corrosion products, fire return film, etc. are not effective, generally should use HNO3-HF solution, in order to facilitate and safe operation, fluoride can be used instead of HF. However,
Some stainless steels are sensitive to
due to poor heat treatment or welding, and
the use of HNO3 plus HF pickles may produce intercrystalline corrosion
, which can concentrate halides during cleaning or subsequent processing. These allergenic stainless steels are generally not suitable for pickring with HNO3-HF solutions. Ultra-low carbon or stable stainless steel should be used after welding if this picky wash is necessary.2, oxidantoxidant is the main component of passivation cream
, often used in the rich hydrochloric acid, thick nitric acid, hydrogen peroxide, potassium chromate, potassium chromate and other substances.3, fillerthe role of the filler is
to give the acid wash passivation paste a certain hardness and viscosity, so that it can be made into a paste, often used magnesium-containing compounds
, magnesium nitrate, magnesium fluoride, magnesium sulfate and other substances, can also be selected as a molding agent. For example: Magnesium nitrate as a filler, can improve the adhesion and penetration of acid wash passivation cream.4, thickenerthickener effect is
to improve the viscosity of acid wash passivation cream
, often used as a thickener substances have stelipidates, such as magnesium stelipidate, can also choose other types of thickeners.5, inhibitorsin order
prevent the metal surface corrosion caused by
over-washing, often add some corrosion inhibitors. Corrosion inhibitors are divided into organic corrosion inhibitors and inorganic corrosion inhibitors. Frequently used inorganic corrosion inhibitors are vanadium, silicate, phosphate, polyphosphate, and organic corrosion inhibitors are benzodiazepines, ulotols and other amine-type substances.6, regulator stainless steel pickry passivation cream generally added the appropriate amount of water as a viscosity regulator, to
change the viscosity and hardness of the paste
. stening outward breakthrough looking for profound changes inwards Hefei Huaqing is committed to real innovation successfully developed efficensive stainless steel pickle passivation cream does not contain strong acids, low corrosion! ,~
SUS300 (SUS303、304、316、316L)
、、、、、,,。 Really achieve the effect of pickling, passivation two-in-one. If necessary, you can contact us.
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