Pickling & Passivation

Multinal Group has the right expertise to effectively stain and passivate stainless steel such as:

sheet metal, tubes, piping, piping, mounting parts, gratings, frames, tubes, heat exchangers, flanges and housings.

With several pickling plants in the Netherlands, we know exactly what is involved in the correct and professional treatment of your product. In addition to the shape, the size and the best applicable technology, we of course closely monitor our pickling procedures with regard to the environment, safety and acid residue treatment. This way you can be sure that the corrosion resistance and thus the durability of your product is enhanced.


Options for pickling and passivation

  • Pickling and passivation of stainless steel, aluminum and carbon steel according to ASTM A380 standards;
  • Support and set up a specific pickling procedure for your customer;
  • Pickling treatment is also possible according to your customer’s standard;
  • Pickling in immersion baths or spray pickling in our pickling plants
  • Pickling at your location in the Netherlands or at an international location.

Why pickling and passivating stainless steel?

  • A chromium oxide layer is created naturally on the surface of the stainless steel, which gives the material its protection.
  • This chromium oxide layer is damaged by the various mechanical operations such as: sawing, cutting, setting, milling and welding.
  • Due to these operations there is a risk of “iron inclusion” taking place. As a result, stainless steel can eventually rust.

About the treatment

By pickling processed stainless steel in a solution of, for example, nitric acid with hydrogen fluoride, carbides, iron particles, but also annealing, rolling, forging and casting skin are removed from / from the surface. After the pickling treatment, the parts are rinsed thoroughly and the chromium oxide layer (the passivation) can form again naturally.

The formation of this natural passivation can take 24 – 48 hours. Some specifications or customer requirements require an additional passivation operation. By immersing the parts for a certain time in, for example, a nitric acid solution and also rinsing them thoroughly, this passivation layer is formed after 30 minutes.

On location or at one of our locations

You can also contact us for the effective (spray or brush) pickling and passivation of stainless steel piping systems, installations, production units, machines, boilers, heat exchangers, cooling towers, tanks and other production parts at your location.

With years of experience with stainless steel pickling and passivation on location and with several pickling plants in the Netherlands, we have the options for you, so the choice is yours.

For self-pickling of stainless steel or stainless steel products


Multinal offers various products for treating your product (s) yourself. Precisely because these stain products are non-toxic, and therefore a lot less environmentally harmful and more people-friendly than the current products on the Dutch market, we not only offer the products to you, but also use them ourselves on location and in our pickling plants. In this way we directly contribute to more environmentally friendly production and improve the health and safety conditions of our people.