| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a surface treated steel sheet for a can excellent in performance, such as oxidation resistance (yellowing resistance) and coating adhesion, by controlling electrolysis conditions and achieving an amount of a phosphate film having a desired adhesion amount of P. <P>SOLUTION: A steel strip is subjected to degreasing and acid pickling. After forming a tin layer on the surface of the steel strip, the phosphate film having a controlled adhesion amount of P is formed on the tin layer by performing PR electrolytic treatment using forward/backward inverted cycle current at least twice in a PR electrolytic treatment bath containing an inorganic phosphate compound. Also, in the PR electrolytic treatment, the steel strip is subjected to cathodic treatment and then anodic treatment, and further, the PR electrolytic treatment is performed by repeating a cycle in which the cathodic treatment and the anodic treatment are performed, and then the cycle of the PR electrolytic treatment is terminated by the anodic treatment. Preferably, in the PR electrolytic treatment, anodic treatment time (a) of the steel strip in one cycle is set to be longer than cathodic treatment time (c), and also the anodic treatment time of that one cycle is set to be 0.3-0.8 sec. <P>COPYRIGHT: (C)2013,JPO&INPIT |
