Description

TR-392 Zinc - Nickel Alloy Blue Trivalent Chromium Passivation

Name: Fengfan Zinc Nickel Alloy Black Trivalent Chromium Passivation TR-392
Brand: Fengfan International Trade
Availability: InStock
Rating: 5 (1 reviews)

1. FEATURES

Environmentally friendly black passivation without hexavalent chromium, suitable for rack and barrel plating.

A dense black passivation layer can be formed on the zinc nickel alloy coating, which has strong anti-corrosion ability.

The passivation solution has a long service life and is easy to operate and maintain.

2. PROCESS FLOW
Zinc nickel alloy plating (preferably reaching over 8μm)→ Rinsing → Rinsing → Activate → Rinsing→ Immersion in TR-392 → Rinse → Rinse → Sealing → Dry

3. OPERATION CONDITIONS

Operation Conditions	Optimal	Operating Range
TR-391A	80ml/l	70-110ml/l
TR-391B	80ml/l	70-110ml/l
pH Value	1.9	1.8-2.3
Passivation Time	75s	65-90s
Passivation Temperature	28℃	25-35℃

Functional Positioning for Automotive Finishes
TR-392 is engineered as a high-performance trivalent chromium passivation specifically designed for zinc-nickel alloy layers (containing 12-15% nickel). It targets the high-end automotive and aerospace sectors where hexavalent chromium is banned, yet extreme corrosion resistance and a distinct black aesthetic are mandatory. This product allows specialized metal plating services to offer a compliant, premium finish that meets strict OEM specifications. It is designed for processors who need to achieve a consistent "piano black" appearance without the iridescence often found in inferior passivates. By adopting TR-392, facilities can transition seamlessly from legacy processes to sustainable manufacturing, ensuring they remain competitive in a market driven by environmental regulations and high durability standards for safety-critical components.

Chemical Architecture and Reaction Kinetics
The core chemistry of TR-392 utilizes a proprietary blend of trivalent chromium salts and organic oxidizers that react with the zinc-nickel substrate to form a dense conversion coating. Unlike standard passivates, this formulation is optimized to work effectively at moderate temperatures (25-35°C), reducing energy consumption. A key technical parameter is its ability to accept a post-dip sealer immediately, which locks in the color and boosts corrosion protection. As a leading electroplating supplier, we have formulated TR-392 to be robust against impurity buildup, specifically zinc and iron, which extends the bath life. The solution operates within a controlled pH range, creating a stable reaction environment that produces a nanostructured film capable of maintaining barrier integrity even under thermal stress.

Industrial Application and Value Proposition
In the industrial landscape, TR-392 is the standard-bearer for finishing components like brake calipers, fuel line fasteners, and chassis brackets. The black finish serves both a cosmetic function, offering a sleek look preferred by luxury brands, and a functional role by providing extended protection against white rust. For providers of plating solutions, this product simplifies the supply chain by offering a single additive that works effectively for both rack and barrel plating lines. It eliminates the need for expensive silver-based blackening agents. The TR-392 coating creates an excellent base for organic topcoats or torque-modifying lubricants, ensuring that the final assembly meets both the aesthetic and mechanical requirements demanded by modern engineering applications involving electroplating chemicals.

Product Advantages

Ecological Trivalent Matrix Design
The structural design of the TR-392 film is based on a trivalent chromium matrix that is completely free of hexavalent chromium and cobalt. This ecological architecture complies with RoHS, ELV, and WEEE directives, removing the toxicity risks associated with traditional black chromating. By switching to these safer electroplating chemicals, plating shops drastically reduce their hazardous waste treatment burden. The passivation layer forms a complex conversion coating that integrates seamlessly with the zinc-nickel lattice. This integration prevents the "rub-off" issues common with dye-based or silver-based black passivates. The film remains stable under thermal shock, meaning parts can be baked for hydrogen embrittlement relief without losing their corrosion resistance, a significant advantage for metal plating operations treating high-tensile steel fasteners.

Aesthetic Consistency and Stability
Achieving a uniform black color on zinc-nickel alloys is notoriously difficult due to alloy variation. TR-392 addresses this through a "Color-Stabilizing" module that ensures consistent reaction rates across high and low current density areas. This innovation eliminates the "rainbow" effect or gray edges often seen on complex shaped parts. For a facility offering metal plating services, this consistency reduces internal rejection rates and quality control overheads. The resulting finish is a deep, glossy black that rivals the appearance of e-coat but with the cathodic protection of the underlying plating. This visual uniformity is maintained even after the thermal shock of curing sealers, ensuring that the final parts delivered to the assembly line match the master sample perfectly every time.

Operational Adaptability and Maintenance
From a systems perspective, TR-392 is designed for high adaptability within existing plating lines. It does not require specialized tanks or exotic heating systems; standard PVC-lined tanks and filtration are sufficient. The solution chemistry is compatible with a wide range of topcoats and sealers, allowing the electroplating supplier to tailor the final coefficient of friction according to customer specifications. The bath management is straightforward, relying on simple titration and pH control rather than complex instrumental analysis. This user interaction optimization means that line operators can maintain the bath within optimum parameters with minimal training. Furthermore, the robust nature of the passivation liquid means it has a long service life, reducing the frequency of bath dumps and new makeups, thereby optimizing the total cost of ownership for the metal plating operation.

Use Scenarios

Automotive Fastener Manufacturing
A Quality Manager at a Tier 1 automotive fastener plant oversees the finishing of high-strength bolts. The specification calls for a zinc-nickel alloy with a black finish that must withstand 720 hours of salt spray testing. The manager selects TR-392 as the passivation step. The process involves plating, followed by the TR-392 dip, and finally a sealer. The manager relies on the consistency of these plating solutions to ensure that every batch meets the friction coefficient requirements for automated assembly. The black color serves as a visual identifier for specific metric bolts on the assembly line. By using TR-392, the plant ensures that the bolts do not corrode during ocean shipping or after installation in the vehicle chassis, protecting the brand's reputation for reliability.

Commercial Job Shop Processing
A Line Supervisor at a commercial job shop manages a flexible line that processes everything from hydraulic fittings to electrical connectors. They face a diverse range of part geometries, necessitating a passivation process that works well in both rack and barrel applications. The supervisor utilizes TR-392 because of its excellent throwing power and color uniformity. When processing a barrel load of small clips, the liquid penetrates the mass to coat every surface evenly. The supervisor values the technical support from their electroplating supplier, who helps adjust the immersion time to balance color depth with throughput speed. The robustness of TR-392 against iron contamination means the supervisor spends less time troubleshooting bath issues and more time meeting production targets using reliable electroplating chemicals.

OEM Validation Laboratory
A Materials Scientist in an OEM validation lab is testing new coating systems for next-generation electric vehicles. The focus is on replacing cadmium and standard zinc with high-performance zinc-nickel. The scientist prepares panels treated with TR-392 for accelerated corrosion testing (CASS and NSS). They analyze the cross-section of the passivation layer using SEM (Scanning Electron Microscopy) to verify the film thickness and density. The results confirm that the plating solutions used in TR-392 form a barrier that effectively retards the oxidation of the zinc-nickel layer. The scientist issues a validation report approving TR-392 for use on exposed brackets and battery housings, citing its superior environmental performance and aesthetic stability under UV and thermal stress, recommending it to their approved metal plating services.

About Us

Shandong Fengfan Electrochemical is a pioneering force in the surface finishing industry, dedicated to the research, development, and manufacturing of advanced electroplating additives. With a heritage of innovation, we have transitioned from a local chemical provider to a global partner for high-end metal plating facilities. Our core expertise lies in zinc alloy plating and trivalent chromium passivation technologies. We are not merely a trading entity; we are primary manufacturers with a state-of-the-art synthesis plant and a dedicated application engineering center. Our product portfolio, including the TR-392 series, is designed to meet the rigorous standards of the automotive, aerospace, and electronics industries. We collaborate closely with our clients to solve complex finishing challenges, offering tailored plating solutions that balance performance, cost, and environmental compliance. Our commitment to quality is reflected in our ISO 9001 certification and our relentless pursuit of greener, safer chemistries. We empower our partners to achieve defect-free finishes that stand the test of time.
Contact our technical experts today to request a sample of TR-392!

FAQ

What is the optimal Zinc-Nickel alloy composition for TR-392?
TR-392 is optimized for zinc-nickel alloys containing 12-15% nickel. This alloy range ensures the best receptivity for the passivation film, maximizing both the corrosion resistance and the depth of the black color.

Does TR-392 requires a sealer for maximum performance?
While TR-392 provides significant corrosion resistance on its own, we highly recommend applying a topcoat or sealer. This is standard practice for metal plating services to protect the black color, enhance scratch resistance, and extend salt spray performance to over 720 hours.

Is this process compliant with environmental regulations?
Yes, TR-392 is a trivalent chromium process that is fully compliant with RoHS, ELV, and REACH regulations. It allows facilities to avoid the use of toxic hexavalent chromium while still using high-performance electroplating chemicals.

Can TR-392 be used in barrel plating lines?
Absolutely. The formulation has excellent covering power and stability, making it suitable for both rack and barrel plating operations. It ensures uniform black coverage even on small, tumbling parts processed by your electroplating supplier.

What operating temperature is required?
TR-392 operates efficiently at low temperatures, typically between 25°C and 35°C. This low-energy requirement helps facilities reduce utility costs while maintaining stable reaction kinetics for the plating solutions.