ALKALINE ZINC COATING
Our alkaline zinc coating process provides excellent adhesion, uniform thickness and high visual appeal.
Our fully automated alkaline zinc coating line is equipped with advanced inner-outer conical perforated drum technology. This enables high-capacity, fast, efficient and internationally compliant zinc coating services.
Zenit Surface Technologies ensures quality control at every stage of the process, delivering top-level solutions both in corrosion resistance and aesthetic appearance.
Standards: ISO 4042, ASTM B633, DIN EN 12339, DIN EN 50961, BRS 17 1005, BOSCH N67F 821 69, VW TL217, DIN 50979, DBL 8451, BMW GS 90010, ISO 4520, TS EN ISO 3613, ISC-B11, VW 13750, CNH MAT0320, DBL 8451, FORD WX100, WABCO JED256
Zinc Nickel Coating
Superior corrosion resistance even at low thickness; proven performance under ASTM B117 NSS conditions.
Eco-friendly alkaline zinc-nickel coating fully complies with RoHS and REACH directives.
Transparent/black passivation options are applied as needed; highly efficient for parts suitable for drum systems.
Delivers durable and reliable coating solutions for automotive, machinery and industrial applications.
Standards: DBL 8451, BMW GS 90010, ISUZU ISC-B11-004J, VW 13750, FORD WX100, VW TL244, DIN 50962, GME 00252
Hydrogen Embrittlement Relief
Critical heat treatment to remove hydrogen diffused during coating, pickling or welding of high-strength steels.
This process is vital to prevent microstructural fractures and unexpected mechanical failures.
Typically applied at 200–250 °C for 2, 4 or 6 hours.
- 200 – 250 °C temperature range
- 2, 4 or 6 hours baking
Longer annealing (200–300 °C) may be applied upon request.
Parameters are set according to material properties and standards (ASTM F519, ISO 9587).
- Hydrogen atoms are removed from the lattice
- Risk of brittle fracture minimized
- Ductility preserved in high-strength steels
- Safe and long-lasting part performance
Process executed with calibrated furnaces and precise temperature control for repeatable quality.
Passivation and Sealer Applications
Enhances corrosion resistance with Cr+6-free processes that form a protective film.
Passivation forms a nano–micro scale protective oxide/hydroxide film on zinc coatings.
Cr+3 based passivations (white/yellow/black) applied in compliance with environmental directives.
- Cr+3 White Passivation – High brightness
- Cr+3 Yellow Passivation – Traditional protection
- Cr+3 Black Passivation – High resistance, decorative
Sealer applications improve performance:
- Fills micropores, 2–3× corrosion resistance
- Optimizes friction coefficient
- Repeatable torque values
- High durability in ASTM B117 / ISO 9227 tests
Parameters controlled by temperature, pH and concentration.
Applications
- Automotive: fasteners, chassis and engine parts
- White goods and appliances
- Electrical-electronics: connectors, contacts
- Defense industry: critical components
- Machinery and construction components
Phosphating Processes
Essential preparation and protection for steel, galvanized steel and aluminum surfaces.
Provides the following advantages:
- Preparation and adhesion for painting
- Improved corrosion resistance
- Enhanced paint adhesion
- Reduced friction during forming
- Less wear in metal-to-metal contact
Zinc Phosphate Coating
Ideal pretreatment for powder/e-coat/plastic; high corrosion resistance and long-term performance.
Manganese Phosphate Coating
Provides wear resistance, dark rough surface; optional oiling reduces friction and extends life.
Applications
- Defense industry
- Automotive
- Machinery and moving parts
Standards:
- VW 13750
- MIL-DTL-16232G
- DIN 50942
Hot Alkaline Blackening (Black Oxidation)
Provides rust delay and black appearance for iron and steel materials.
Main purposes: delay rusting, provide homogeneous black appearance, suitable for thin coatings.
- Delays rust during storage and use
- Uniform black appearance
- Suitable for dimension-critical parts
Surface Properties
- Polished surface → glossy black
- Matte surface → matte black
Technical Benefits
- Does not change size, hardness, surface
- No risk of hydrogen embrittlement
- Ideal for precision parts
Applied under controlled temperature and concentration for long-term protection.
Stainless Steel Cleaning and Passivation
Removes defects from manufacturing; Cr2O3 passive layer enhances corrosion resistance.
Manufacturing may leave heat stains, weld marks and iron oxide layers:
- Heat stains
- Weld marks
- Color changes
- Iron oxide layers
Cleaning Process
Cleaning removes grease, organics and slag using special chemicals and mechanical methods.
Passivation Process
Passivation forms a controlled chromium oxide layer, enhancing corrosion resistance and durability.
- Increases corrosion resistance
- Ensures long life and durability
- Ideal surface for subsequent processes
Technical and Standard Compliance
Standards applied:
- ASTM A967 / A967M
- ASTM A380
- ISO 8501-1
- SAE AMS 2700
Provides repeatable quality and industry compliance.
Stainless Steel Blackening (SS Black Oxide)
Provides aesthetic black finish; sealer can be applied for enhanced durability.
Process provides black finish and enhances corrosion resistance.
Sealer may be applied depending on use; improves durability and appearance retention.
Standards:
- MIL-DTL-13924
Standards-compliant processes ensure long-lasting black surfaces.