| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for enhancing the corrosion resistance of a mill scale steel in which surface scale need not be removed, surface treatment is unnecessary, and the desired corrosion resistance is demonstrated even when mill scale steel is used without machining. SOLUTION: The method comprises a step for immersing mill scale steel into a solution containing phosphoric acid ions, and a step for drying the mill scale steel after the immersing step, and a phosphate film is deposited on a cracked part in surface scale of the mill scale steel. Alternatively, in place of the immersion, the solution containing phosphoric acid ions is sprayed or coated. In addition, the temperature of the solution containing phosphoric acid ions is 10-80°C, the solution containing phosphoric acid ions contains phosphoric acid ions of 1-30%, and the solution containing phosphoric acid ions is calcium hydrogenphosphate solution (CaHPO<SB>4</SB>) or magnesium hydrogenphosphate solution (MgHPO<SB>4</SB>). COPYRIGHT: (C)2006,JPO&NCIPI
|
