What is the thickness of phosphate coating?
The thickness of various types of phosphate coatings will be of the order of 1 to 50 microns. However, for practical purposes, the coating thickness is usually quantified in terms of weight per unit area (usually as g/sq. m or mg/sq. ft) and commonly referred to as coating weight.
How do you use manganese phosphate coat?
The manganese phosphate coating process includes a specific sequence that normally includes degreasing and cleaning of the metal part, a water rinse, then pickling in mineral acid. This is followed by another water rinse, activation, manganese phosphate, water rinse and lubricating with special oils.
How is phosphate coating weight measured?
Weigh the panel in order to find the baseline weight. Once that is determined, dip the panel into a chromic acid bath, which will remove the phosphate coating from the panel. Weigh the panel again and subtract that weight from the baseline weight to find the phosphate coating weight.
How do you apply phosphate coating?
A phosphate coating is usually obtained by applying to the steel part a dilute solution of phosphoric acid, possibly with soluble iron, zinc, and/or manganese salts. The solution may be applied by sponging, spraying, or immersion.
What is iron phosphate coating?
Iron phosphate coatings are chemical coatings applied to metal surfaces before painting. Phosphating causes a reaction that changes the molecular structure of the surface, providing up to 1,000 times better paint adhesion than an untreated metal surface.
What color is manganese phosphate?
Manganese phosphate coatings, unlike zinc phosphate coatings, also provide continued wear protection after initial break-in. The coating is formed via immersion in a dilute phosphoric acid solution and is dark grey in appearance.
How do I know my coating weight?
There are two methods for measuring the zinc coating thickness of hot-dip galvanized steel; a magnetic thickness gauge and optical microscopy. The simplest and non-destructive way is to utilize a magnetic thickness gauge, as optical microscopy is a destructive test only used to resolve measurement disputes.
Does phosphate coating rust?
Phosphate coating provides strong adhesion and corrosion protection, and also improves the friction properties of sliding components. Some of the threaded parts are treated with phosphate coatings, which improves their anti-galling and rust inhibiting characteristics.
How thick should galvanized coating be?
Thickness should be between 1.4 and 3.9 mils (35 and 100 µm) depending on the coating grade.
What is the thickness of manganese phosphate coating?
These adhesive coatings provide an excellent base for painting. Coating thickness for zinc phosphate is between .0002 and .0006 inches and manganese phosphate coatings are typically between .0002 and .0004 inches thick. APPEARANCE: The color of zinc and manganese phosphate coatings range from gray to black.
What is the pH value of iron phosphate coating?
Iron phosphate coating ranges in color light yellow to blue-red. Coating 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.
How to choose the right steel for manganese phosphating?
Steels to be processed for manganese phosphating should not contain more than 6% alloying elements, as above that value the reactivity of the steel in the phosphating solution is lower than necessary to produce the right crystal structure, or enough coating thickness. The solutions for producing a manganese phosphate are typically proprietary.
How long does it take to make manganese phosphating coatings?
Manganese phosphating is mainly by immersion. Treatment times range from 5-20 minutes, the optimum time depending on the surface condition. The bath operating temperature is around 95°C and only in special cases can satisfactory coatings be formed at temperatures around 80°C.