such as those using Zn–Mn phosphating solution. The phosphating
area formed was more than 0.8 m2 per liter of the phosphating
solution before regeneration of the phosphating solution was
required. The phosphating solution attached on the surface of the
steel samples after phosphating procedure completely deposited as
phosphating layer, which almost doubled the material usage.
Therefore, material consumption and wastewater discharge were
reduced. Hazardous materials such as nitrite and chromium were
not used in the phosphating solution either. Therefore, this phosphating
process was environmentally friendly.
From the experimental results and discussion described above,
we can conclude that this phosphating solution led to a cleaner
production process for steel phosphorization.