The removal and/or restoration of the (old) oxide layer can be done by means of mechanical processes such as brushing, grinding, polishing, tumbling, blasting, electrolytic polishing or by means of pickling and passivation with a mixture of various acids.
Welding methods usually cause a brown-blue discoloration of the material in the weld zone. To restore the appearance and corrosion resistance of this, the material usually also needs to be pickled and passivated.
In most cases, pickling and passivation baths are used for this. However, it is not always possible to use these pickling baths. Think of assembly welding on construction sites and small pickling work in construction workshops. HOLLIMEX has a number of pickling pastes, spray pickling agents and passivation agents in its delivery package for this purpose that give excellent results. You can find these products in our webshop.
CAUTION!
Mordants contain a mixture of acids, such as nitric acid, hydrofluoric acid and other additives. It is highly toxic and corrosive. It is therefore corrosive to the eyes, skin and respiratory organs, inhalation of vapour and/or mist can cause shortness of breath. In severe cases there is even a risk of death.
Therefore, always use protective clothing such as:
First aid for burns to eyes and skin:
First aid for inhalation:
The pickling agents and the rinsing water are not biodegradable and must therefore be delivered to an approved waste processing company. Always ensure that the product cannot end up in surface water and cleaning must be done with liquid-binding agents, such as sand, sawdust or lime.
Hollimex also supplies pickling products that are non-toxic. These products are milder, less environmentally harmful and more human-friendly.
Please note! The times and consumption specified for a named product are approximate. This depends strongly on the ambient temperature, the degree of discolouration and combustion and the applied layer thickness of the product.
After pickling, the objects should be thoroughly cleaned with (demineralised) water, which will create a clean and pure surface and give the stainless steel optimum corrosion resistance.
In case of very high contamination and/or high quality requirements, we advise to pickle and passivate separately. Passivation after a pickling treatment is a very precise and important process. This process ensures that optimum corrosion resistance is obtained. Passivation can take place naturally or be accelerated by means of chemical passivation.
HOLLIMEX has various products in stock. Think of pickling, passivating and cleaning agents, tools, acid-resistant brushes and protective aids such as (acid-protective) gloves, goggles etc.
More information about "PICKLING, PASSIVATION, PICKLING PRODUCTS, TREATMENT SYSTEMS AND ACCESSORIES FOR STAINLESS STEEL" can be found in our WEBSHOP.
