Iron Phosphate Pretreatment System
Products Description of Iron Phosphate Pretreatment System
- Iron Phosphate Pretreatment Systems. Iron phosphate systems, also known as alkali metal phosphates, are used for parts that require a durable finish but are not exposed to severely corrosive environments. These systems can involve two to six stages, with the shortest sequence being a cleaner-coater stage followed by a tap-water rinse. Short sequence systems are employed if performance requirements are low.
- Parts that are more difficult to clean or have higher quality requirements call for a separate cleaning stage, appropriate rinse tanks, iron phosphate, post-treatment rinse, and a DI rinse. A post-treatment rinse (chrome or non-chrome) results in improved corrosion performance over the phosphate alone.
- Iron phosphates produce an amorphous conversion coating on steel that ranges in color from iridescent blue to gray, depending on operating conditions and product formulation. Mixed metals may be treated with modified formulas that typically contain fluoride.
- Iron phosphate processes are much easier to operate and require fewer process stages than zinc phosphating. However, iron phosphates do not provide the degree of corrosion protection imparted by zinc phosphates.
- Zinc Phosphate Pretreatment Systems. A zinc phosphate system varies from an iron system in two critical areas. First, it requires the use of a surface conditioner stage. Second, a zinc phosphate bath has additional metal ions in the solution which are incorporated into the coating along with the metal ions from the substrate being processed.