phosphating is the most preferred conversion coating method
for indoor equipments due to its advantage of low first investment
cost and unit prices of the chemicals.
Iron phosphate coating chemicals are
easy to use products that can be used by wiping, spraying or
dipping for the metal surfaces do not require high corrosion
IRON PHOSPHATE CONVERSION COATING BY APPLICATIONS;
phosphate coating ranges in color
light yellow to
weight is generally between 0.2 - 1.0 gr/m2.
Concentration of the coating solution varies in the range of %1 – 10
and operating temperature is between room temperature – 65 °C.
Optimum pH value of phosphating solution is 4 to 6. Below pH 4
dusty coating may occur and above pH 6 coating may be loose and
phosphate coating is not a thick coating relatively, passivation and
drying stages should be operated carefully. When outbreak of
oxidation (rust) is observed after the treatment, this indicates
insufficient coating on the metal surface. Iron
phosphate coated but unpainted metal
workpieces do not have improved corrosion protection, that’s why it
is an advantage to paint the phosphated surface immediately after
phosphating increases paint adherence and impact resistance along
with improved flexibility. Treated metal surface has the ability to
stop progress of oxidation underneath the paint when damaged by an
iron phosphating suitable for ferrous metals, by the advantage of
surfactant content, it can also be employed in cleaning and etching
of aluminium or galvanized metals.
phosphating applied by
spraying, phosphating and
degreasing can be operate
at the same stage with proper quantity of both chemicals.