To provide a surface treatment solution and treatment method for gold or gold alloy plating that effectively suppresses corrosion of underlying metal or substrate metal from pinholes that develop on the gold or gold alloy plating film. [Solution] A surface treatment solution containing a disulfide compound is brought into contact with a gold or gold alloy plating film. A compound represented by the following formula (2) is preferred as the disulfide compound.
X.sup.1O.sub.3S—R.sup.3—S—S—R.sup.4—SO.sub.3X.sup.2  (2)
in the formula, R.sup.3 and R.sup.4 independently represent a linear or branched alkylene group having from 1 to 10 carbon atoms, cyclic alkylene group having from 3 to 10 carbon atoms, or phenylene group, R.sup.3 and R.sup.4 independently may be substituted by one or more substituents selected from an alkyl group, halogen atom, hydroxyl group, or alkoxy group, and X.sup.1 and X.sup.2 represent monovalent cations.

The present disclosure relates generally to the field of conversion coating. More specifically, the present disclosure relates to improved methods for improving efficiency of chromium conversion coat processing lines.

The present disclosure relates generally to the field of conversion coating. More specifically, the present disclosure relates to improved methods for improving efficiency of chromium conversion coat processing lines.

The present disclosure relates generally to the field of conversion coating. More specifically, the present disclosure relates to improved methods for improving efficiency of chromium conversion coat processing lines.

The present disclosure relates generally to the field of conversion coating. More specifically, the present disclosure relates to improved methods for improving efficiency of chromium conversion coat processing lines.

The present disclosure relates generally to the field of conversion coating. More specifically, the present disclosure relates to improved methods for improving efficiency of chromium conversion coat processing lines.