ADL -32: Passivation Solutions for Quench Tanks

What is ADL -32?

ADL -32 is a Chromium III (Cr3+) passivation chemical for hot-dip galvanized (HDG) steel, used directly in the Quench Tank after the galvanizing process.

This product creates a thin transformation film on the zinc surface, reducing white rust , increasing corrosion resistance, and meeting the trend of replacing Chromium VI (Cr6+) technology with environmentally friendly solutions.

This product, ADL -32, creates a thin transformation film on the zinc surface, reducing

Developed by AD Chemicals (Netherlands) , the ADL-32 passivation product for hot-dip galvanizing is suitable for modern HDG lines that want to improve product quality without major equipment changes.

Key Benefits of ADL -32

Chromium III (Cr3+) technology does not contain Cr(VI).

Use directly in the Quench Tank ; no separate passivation tank is required with ADL -32.

Reduce the risk of white rust formation during storage and transportation.

Increase the corrosion resistance of galvanized steel products.

Low investment cost, easy integration into existing production lines.

In line with green production trends and export requirements.

Specifications

ADL-32 Usage Procedure

The passivation chemical for hot-dip galvanizing, ADL-32, is added directly to the Quench Tank, combining the cooling and passivation processes in a single step, thus simplifying the production process.

ADL-32 passivation process

When Should You Choose ADL-32?

Passivation for hot-dip galvanizing – ADL-32 is a suitable option when businesses:

Quench Tanks are already present in the HDG production line.
We want to upgrade from Cr(VI) technology to Cr3+ .
The phenomenon of White Rust needs to be limited .
We want to optimize investment costs.
No intention of renovating or adding a separate passivation tank.

If a business wants to separate the passivation process, then it should use ADL-3P or Spray Passivation.

Comparison of Passivation Products for Hot-Dip Galvanizing

ADL-32 Suitable For

Galvanized steel structure
Electric pole
Telecommunication pole
Railing
Solar panel mounting bracket
Prefabricated steel buildings

Corrosion Resistance Test Results

1. Neutral Salt Spray (NSS) Testing

The ADL-32 passivation for hot-dip galvanizing has been tested according to high quality standards for the hot-dip galvanizing industry.

The test results showed that:

Superior corrosion resistance.
The White Rust phenomenon is effectively controlled.
The surface remained clean and stable after testing.

The image shows that the surface behind the NSS remains clean, with high white rust protection.

2. 24-hour Humidity Test:

24-hour humidity tests showed that the ADL-32 passivation layer performed stably and provided good protection to galvanized steel surfaces.

After the testing process:

The surface remains bright and clean.
No premature oxidation occurred.
No white corrosion marks form.

Moisture test results showed that ADL-32 maintained a stable surface, without premature corrosion or white spots forming.

Comparison of ADL-32 Passivation with Chromium(VI) Chromate Technology

Criteria	Chromate (Cr VI)	Passivation ADL-32
Environmental impact	-/- (bad)	++ (very good)
Resistance to white rust	++	++
Chemistry foundation	Chromium(VI) – toxic	Chrome(III)
Operating procedure	++	++
Quality standards	Meets standards	Meets standards
Use directly in the tank.	YES	YES
Use after a cooling bath.	YES	YES
Coating color	Gold or transparent	Transparent, colorless
Wastewater treatment	Complex (removes Cr VI)	Normal handling
Easy to clean if needed.	NO	YES
Price	€	€€ (slightly higher)

Frequently Asked Questions (FAQ)

In which stage of the hot-dip galvanizing passivation product ADL-32 is used?

ADL-32 is used in the Quench Tank immediately after the hot-dip galvanizing process, in combination with the cooling and passivation process.

Can ADL-32 replace Cr(VI) technology?

Yes. ADL-32 uses Chromium III (Cr3+) technology and was developed to replace Chromium VI-containing passivation systems in many HDG applications.

Does ADL-32 help reduce white rust?

Yes. The conversion film created by ADL-32 helps reduce the risk of white rust formation during storage and transportation. The effectiveness depends on the quality of the coating and the operating conditions of the production line.

When should you choose the ADL-32 passivation product for hot-dip galvanizing instead of ADL-3P?

The ADL-32 is suitable for production lines that already have a Quench Tank. If the business has its own passivation tank after the cooling process, the ADL-3P would be a more suitable option.

Is ADL-32 suitable for current environmental requirements?

Yes. The passivation chemical for hot-dip galvanizing, ADL-32, does not contain Chromium VI and does not contain SVHC, aligning with environmentally friendly production trends and the requirements of many export markets.

Reference for Passivation Chemicals for Hot-Dip Galvanizing

Reference Materials for Metal Surface Treatment

DK-Chemicals: Metal surface pretreatment solutions for industry

DK-Chemicals provides chemical surface treatment solutions for metals serving the aluminum, galvanized sheet, color-coated steel, coil-coating, and related industrial applications.

With a focus on providing advanced, environmentally friendly technologies that meet modern production requirements, DK-Chemicals partners with customers in selecting suitable pre-treatment solutions, optimizing surface quality, and enhancing product durability after coating.

Contact DK Chemicals’ technical team today for detailed advice .

DK Chemical Company Limited

Address: 50 Street No. 12, Cityland Park Hills Residential Area, Go Vap Ward, Ho Chi Minh City

Hotline: 0909678599

Email: de@dk-chemicals.vn