Product Categories / Metal Treatment / Passivation

Durapass 712

Product description

Durapass 712 is a specifically formulated chrome free liquid blended product based in zirconium. It is used where strict environmental condition does not allow the use of chromium based products for the passivation of metals.


  •  Durapass 712 is formulated product to be used for immersion and spray systems for most of the steel iron.
  •  Durapass 712 forms colorless fine passivated coating on work piece after phosphating of steel to enhance anticorrosion protection and eliminate salt water contamination on the surface.


  • Durapass 712 is an environmental friendly product producing thin, uniform and transparent chromium
    free passivation at low concentration and temperature on metals.

Physical & Chemical Properties

Appearance :Liquid.
Color: Colorless to yellowish.
pH (1% ) at 25oC :3.4 ± 0.3
Sp. gr at 25oC: 1.09 ± 0.03
Total Acid point:  2.5 ± 0.1
(1%) Miscible.


Tank can be fabricated from hard PVC or stainless steel or fluoride resistant plastic. All other equipments in contact could be of SS316 (L).

Process Sequences

  •  Phosphating with Duraphos products system or galvanizing process.
  •  DI Water Rinse
  •  Passivation with Durapass 712.
  •  Drying

Operating Parameters

Concentration (%v/v) :3 to 5
Pointage :7 to 13
Temperature (oC) :25 to 40
Time (min) :1 to 3
Nozzle pressure (Bar) (in spray) :0.5 to 1.0
pH :4 to 5

Initial preparation:

Add 30 to 50 liters of Durapass 712 per 1000 liter
of operating volume.


D.I water should be used to prepare the bath with
max conductivity 50 μS.

Reagents & Equipments

  •  0.1 N Sodium Hydroxide Solution.
  •  Phenolphthalein Indicator.
  •  Conical flask 100 ml.
  •  Glass Burette 50 ml.
  •  10 ml Pipette.