4. Conclusions
This cleaner steel phosphorization, which can produce high
quality colorful phosphating layers, uses the Zn–Mn phosphating
solution at temperature ranging from 3 to 35 C. Hazardous materials
including nitrite, chromium, and nickel are not used in the
phosphating solution. The operation parameters of the phosphating
process can be adjusted in a broad range. Pretreatment before
phosphating procedure and rinsing after phosphating procedure
are omitted. All the phosphating solution attached on the surface of
the phosphating layers covering the steel specimens is used for
phosphating layer development, which significantly saves the
material consumption and reduces the wastewater discharge.