NIPPON STEEL CORPORATION

Quality characteristics of ZAM

Electrical conductivity

ZC treatment
Chromium-free inorganic treatment

① Excellent electrical conductivity

The inorganic film has low electrical resistance and excellent surface conductivity (spot weldability).

② Corrosion resistance

The resultant film has corrosion resistance equivalent to that obtained in the case of chromate treatment (A treatment).

③ Superior compatibility with the environment

The resultant material is friendly to the environment because its film is entirely free of chromium.

ZC treatment Chromium-free inorganic treatment

Quality characteristics

Treatment Elution of chromium Corrosion resistance
（SST72h）		 Contact resistance value
（grounded）		 Fingerprint resistance Alkali resistance Solvent resistance
Ethanol Acetone
ZC treatment No elution White rust occurrence 10% or less 10-5〜10-4Ω ΔL≤1.0 OK OK OK
Chromate treatment(A treatment) Elution White rust occurrence 10% or less 10-5〜10-4Ω ΔL≤1.0 OK OK OK
Elution of chromium: Amount of chromium elution measured after the specimen has been immersed for 3 minutes in boiling water
Corrosion resistance: Salt spray test (JIS Z2371)
Contact resistance value: Measured by the four-terminal, four-probe method (Dia Instruments MCP-TPO3P)
Fingerprint resistance: Difference in brightness (ΔL) before and after impression with artificial finger-smudge solution (JIS K2246)
Alkali resistance: Appearance after immersion for 2 minutes in alkali degreasing agent (Nippon Paint SD-270) adjusted to pH of 12 and a temperature of 40ºC
Solvent resistance: Appearance after rubbing 5 times with gauze impregnated with the solvent
(Evaluation standard/ ○ : no change, △ : some discoloration, × : film peeling)

Corrosion resistance of flat part

ZC treatment: Coating weight symbol 90, thickness: 0.8 mm
A treatment: Coating weight symbol 90, thickness: 0.8 mm
Untreated: Coating weight symbol 90, thickness: 0.8 mm
ZC treatment
Corrosion resistance of flat part: ZC treatment
A treatment
Corrosion resistance of flat part: A treatment
(Reference)Untreated
Corrosion resistance of flat part: (Reference)Untreated

Reference scale: 20mm

Appearances after 72 hours of salt spray test (SST)
No significant change in appearance was found in the ZC treated material even with SST lasting 72 hours.

Corrosion resistance of bent part

ZC treatment: Coating weight symbol 90, thickness: 0.8 mm
A treatment: Coating weight symbol 90, thickness: 0.8 mm
Untreated: Coating weight symbol 90, thickness: 0.8 mm
ZC treatment
Corrosion resistance of bent part: ZC treatment
A treatment
Corrosion resistance of bent part: A treatment
(Reference)Untreated
Corrosion resistance of bent part: (Reference)Untreated

Reference scale: 10mm

Appearances of bent parts after 24 hours of humidity cabinet test (BBT) (90º bend, bending radius: 1 mmR)
No significant change in appearance was found in the ZC-treated material even with BBT lasting 24 hours.

Product shape

ZC: Product shape