Welcome to Jiangsu Lichao New Material Technology Co., Ltd.
What are the passivation treatment methods for stainless steel strips
source：www.cnlichao.net | Release time：2026年09月28日Soak the stainless steel strip in nitric acid bath to remove surface free iron impurities and promote chromium oxidation to form a dense passivation film. Can be divided into multiple concentration levels, suitable for austenitic stainless steels such as 304 and 316; The disadvantage is the generation of nitrogen oxide waste gas, strict environmental control, and some industries have restricted its use, following the ASTM A967 nitric acid specification. It can be soaked in continuous immersion tanks or segmented immersion, suitable for batch processing of coil materials.
2. Citric acid immersion passivation (environmentally friendly chemical passivation)
Soaking in a citric acid system solution, free iron on the surface is removed through chelation to form a passivation film. No smoke, easy to treat waste liquid, preferred for industries such as medicine, food, and clean equipment. It has minimal corrosion to the material substrate and does not change the appearance of the steel strip. It is suitable for precision stainless steel strips and corresponds to ASTM A967 citric acid type.
3. Spray passivation
Passivation agents are applied to the surface of stainless steel strips by spraying, without the need for soaking tanks, suitable for continuous production lines of wide and long coils, and with small equipment footprint; The medicinal solution can be recycled. Mostly used for online continuous processing of thin steel strips, strict control of spray uniformity is required to avoid insufficient local passivation.
4. Apply passivation paste for passivation
Paste like passivating agent, generally used for local repair. Stainless steel strip is used for local iron contamination points after slitting and welding, which is not suitable for large-scale continuous production of whole steel strip and is mostly used for later repair.
5. Electrochemical passivation (electrolytic passivation)
Direct current is applied to the electrolyte, and under the action of the anode, the surface of the steel strip rapidly accumulates chromium elements, generating a more uniform, stable, and corrosion-resistant passivation film. The passivation film has high quality and is suitable for stainless steel strips with precision and high corrosion resistance requirements; High equipment investment results in higher costs.
6. Integrated electro polishing and passivation
Electropolishing belongs to electrochemical surface treatment, which not only flattens the micro surface, but also enriches the surface chromium and simultaneously generates excellent passivation film. Not only passivation, but also polishing effect, significantly reducing surface roughness; It can be used to thin materials in small amounts and is generally used for BA mirror surfaces and stainless steel strips for high-purity fluid equipment.
prev:
What is the usual method for controlling the shap…
next:
How is the corrosion resistance of stainless stee…
【Related articles】
Jiangsu Lichao New Material Technology Co., Ltd.
+
WeChat ID:jinjiayi0512
WeChat ID:jinjiayi0512
Add WeChat
Contact us
The phone