JW-818 Trivalent Chromium Black Passivation Agent
Category:
Detailed description:
01
This product is a single‑component, trivalent chromium black passivation agent suitable for potassium chloride–based acidic zinc plating. It is widely used in the automotive, electronics, and toy industries. The undiluted formulation contains no hexavalent chromium and complies with the IEC 62321 standard of the International Electrotechnical Commission.
02
It can form a uniform, deep-black, highly protective passivation film on the surface of the zinc coating. The film is black and glossy, scratch‑resistant, and exhibits satisfactory salt‑spray resistance after sealing. It is suitable for barrel plating processes using potassium chloride acidic zinc plating and cyanide zinc plating.
03
This product is a single-dose formulation, offering simple and convenient use and maintenance, with excellent chemical stability and a long service life.
Process and Operating Procedures
Galvanizing—first- and third‑stage water rinsing—activation—water rinsing—trivalent chromium black passivation—water rinsing—hot‑air drying—immersion in oil—drying (at 120°C or higher)
Operating conditions
| Operating conditions | Scope | Recommended tank volume/parameters | ||
| Trivalent chromium black passivation JW-818 | 120–180 ml/L | 150 ml/L | ||
| Temperature | 20-35℃ | 25℃ | ||
| pH value (20% NaOH or HNO3) | 1.6-2.0 | 1.8 | ||
| Impregnation time | 10–30 seconds | 15 seconds | ||
| Drying temperature | 60-80℃ | 70℃ | ||
| Drying time | 3–5 minutes | 5 minutes | ||
| Stirring | Air stirring or mechanical stirring | Stirring | ||
| Water-oil sealing | JW-895:800-1000ml/L | 1000ml/L | ||
| pH value | 7-9 | 8 | ||
| Temperature | 80–150℃ | 120℃ | ||
| Time | 5-15s | 10s | ||
| Stirring method | Static | Static | ||
Keywords:
JW-818 Trivalent Chromium Black Passivation Agent
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