Since stainless steel is corrosion resistant material, not much of oxide scale forms. However, scale forms from heat treatment which is to make the surface even. In order to remove the smut, a mixture of nitric acid and hydrofluoric acid is widely used. Those substances are highly toxic and very hazardous when in contact with human body. It also produces large amount of fume (NO, NO2, HF) and creates poor and dangerous working conditions.
AST-207 is developed to solve these problems ideally.
• Shows excellent removal speed on scale
→ improves productivity
• Shows low harmfulness when in contact with human body, barely creates fume (NO, NO2, HF)
→ accords with environmental standards, reduces NOX gas disposal cost
• Surface roughness (glossiness) improves since the solution does not dissolve the target metal and no excessive corrosion occurs
→ improves product quality
[ Properties and method ]
Colorless transparent liquid
5~20% diluted in water
Light acid odor
55 ~ 60 ℃
Dipping, dipping ultrasonic
1.11 ± 0.02
20L (pail) / 200L (drum)
※ Solution management
(1) Check the initial acidity. (Use tanks and heaters made of acid and heat resistant material such as PP, PE, teflon, etc.)
(2) When the acidity and the amount of the solution decrease, add adequate amount of the original solution in order to reset the acidity back to its initial level
(3) Change to new solution when concentration of iron ion becomes 60~90g/ℓ.
※ Wastewater treatment
To minimize the amount of the sludge, treat with caustic soda + calcium chloride or caustic soda + calcium hydroxide.
[ Application ]
Applicable on all types of stainless steel (Pipe, angle, hot rolled coil, cold rolled coil, sheet, Wire, rod, etc.)