Tegehall, PE, Vannerberg, NG, "Nucleation and Formation of Zinc Phosphate Conversion Coating
on Cold Rolled Steel.
Until recently, Roper Corporation used an iron phosphate conversion coating
that required a bath of 125 to 140oF (52 to 60oC) and a post-treatment rinse stage.
Bonderite[R] 952 is a zinc phosphate conversion coating
formulated for a spray application on substrates such as steel, galvanized and electrogalvanized, zincalloy, and aluminum.
Secondly, a groundbreaking step has been taken to eliminate the traditional zinc phosphate conversion coating
and all of its associated operating conditions creating a simpler and friendly conversion coating.
Phosphate conversion coating
involves the formation of a surface layer of hydrated metal phosphate crystals whose coverage approaches 100%.
These processes are capable of both removing fabricating soils and developing an iron phosphate conversion coating
in one operation.
First significant advantage of the process is that there is no effluent to dispose of after the degreasing stage because the oils and greases removed from the components being treated are absorbed and become part of the polymeric phosphate conversion coating
on steel, aluminium or zin coated steel.
More recently, Zhai and coworkers [Paper 2008-01-1158, SAE World Congress, Detroit, Ml, April 2008, SAE International, Warrendale, PA] showed that painted modified FZ on cold-rolled steel gave corrosion resistance comparable to that of painted phosphate conversion coatings
We also use a wide variety of aqueous chemical solutions such as in acid pickling, phosphate conversion coatings
It is compatible with all lubricants, cutting oils, and hydraulic oils and acts as a topcoat over black oxide and phosphate conversion coatings
to seal out corrosion and provide break-in protection.
In the case of aqueous processes such as amorphous (iron) phosphate conversion coatings
, separate cleaning and rinsing stages can be used before the phosphate stage or as is often the case, cleaning and phosphating can be combined to give a suitable conversion coating.
Nate Goodnow, managing director of PPG Coating Services, said, "The industry has been excited about the introduction of Alltech's level of coatings competence in Taiwan, with state-of-the-art equipment and technology for processing zinc phosphate conversion coatings
and multiple colors of electrocoat.