Restore

Passivation of stainless steel

Promote the passive state of your stainless steel surfaces through treatment adapted to their condition, use, and your facility’s requirements.

Chemical passivation eliminates ferrous contamination and promotes a protective passive layer. Technochim adapts the treatment to the stainless steel grade, surface condition, and your facility’s requirements.

The challenges

Treatment benefits

Restore the passive state

Create favorable conditions for the formation of a chromium-rich passive layer, essential to stainless steel’s corrosion resistance.

Eliminate ferrous contamination

Remove free iron and certain superficial ferrous contamination with treatment adapted to the stainless steel grade and surface condition.

Preserve surface integrity

Integrate passivation into equipment fabrication, commissioning, or maintenance to preserve their properties over time.

Your need

When should passivation be performed?

Technochim defines the treatment according to the stainless steel grade—notably 316L widely used for pharmaceutical process equipment—the initial surface condition, previously performed operations, and your facility’s requirements.

After fabrication, welding, modification, or repair of stainless steel equipment.
After pickling or treatment requiring restoration of the passive state.
When superficial ferrous contamination is identified or suspected.
Before commissioning or recommissioning a tank, piping, or process equipment.
As part of a preventive maintenance strategy for stainless steel surfaces.

Our approach

Treatment defined according to surface and facility

Passivation is not simply the application of a chemical product. The result depends on the initial surface condition, its preparation, the stainless steel grade, the chemistry used, and the process parameters.

Technochim defines the protocol based on the actual surface condition and equipment constraints.

Assess the surface

Identify the stainless steel grade, initial condition, potential contaminations, and treatment history.

Prepare the surface

Define the preliminary operations necessary to obtain a surface compatible with passivation.

Control the passivation

Adapt the chemistry, concentration, temperature, contact time, and application method to the selected protocol.

Rinse, verify & document

Control the rinsing, verify defined criteria, and document the intervention before recommissioning.

Understanding passivation

From preparation to passive layer

Stainless steel’s corrosion resistance relies on an extremely thin passive layer, rich in chromium oxides. It forms naturally on a clean surface when the environment permits. Surface preparation and passivation treatment are adapted to its initial condition and intended operating conditions.

Prepare the surface

Passivation quality depends directly on the surface condition before treatment. Organic residues, oxides, ferrous contamination, or fabrication-related alterations may require preliminary degreasing, cleaning, or pickling operations.

Adapt the passivation process

Chemical passivation is then performed according to a formulation and parameters adapted to the material and facility. Depending on equipment configuration, treatment can be performed by immersion, circulation, filling, or application.

Control the rinsing

Rinsing constitutes a process step in its own right. The protocol specifies their execution conditions and the required water quality according to the treatment and facility requirements.

Affected surfaces and equipment

316L stainless steel process tanks

Process piping

PW/WFI loops

High-purity water production and storage equipment

Clean steam generators and distribution systems

Stainless steel parts and components

Technochim expertise

Mastering chemistry, surface, and facility

Technochim combines knowledge of stainless steels, mastery of surface chemistry, and experience with pharmaceutical and high-purity facilities. This approach enables passivation to be defined based on the actual surface condition and equipment requirements.

Prepare your intervention

Specify your equipment, stainless steel grade, surface condition, previously performed treatments, and your facility's constraints.

These elements will enable preparation of a technical discussion with Technochim.