passivaatori

Passivaatori is a term used in materials science to designate substances, processes, or mechanisms that induce passivation of a material surface, especially metals. A passivator promotes the formation of a protective, adherent oxide layer that reduces corrosion and chemical reactivity, thereby extending the component’s service life in aggressive environments. The word combines passivation with the -ator suffix used for agents or devices.

Most common passivaatori are chemical agents applied in surface treatments. For stainless steels, acids such as nitric acid or citric acid are used to remove free iron and enhance chromium-rich oxide formation. Citric acid is often favored for environmental and safety reasons, while nitric acid provides robust oxide films in many standard industrial practices. Other passivators include oxidizing or complexing solutions, electrolytic treatments like anodic oxidation, and combinations with detergents or chelants. The chosen method depends on metal composition, required film properties, process economics, and downstream use.

Validation and standards: Passivation procedures are governed by industry standards and guidelines, such as ASTM A380 and A967 for stainless steel and other alloys, which specify cleaning, passivation, and quality-control steps. Evaluation methods include visual inspection, surface analysis, and corrosion tests to verify film effectiveness. Safety and environmental considerations address chemical handling, waste treatment, and disposal. See also passivation (chemistry), corrosion, stainless steel, and passivation standards.