Black inactivation process for zinc-nickel alloy coating

Black inactivation process for zinc-nickel alloy coating

  • CN 1,148,464 C
  • Filed: 12/30/1999
  • Issued: 05/05/2004
  • Est. Priority Date: 12/30/1999
  • Status: Active Grant
First Claim
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1. , a kind of black inactivation process of zinc-nickel alloy coating, this passivation technology divide pre-passivation and two steps of sealing passivation to carry out, and it is characterized in that:

  • Contain following composition in the pre-passivating dip;

    Chromic anhydride;

    greater than 0~

    10 grams per literNitric acid;

    10~

    60 milliliters/literSulfuric acid;

    greater than 0~

    50 milliliter/literNaF;

    greater than 0~

    5 grams per liter;

    The sealing passivating dip contains following composition;

    Sodium dichromate 99, or potassium bichromate;

    greater than 0~

    100 grams per liter.

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