STEEL MATERIAL AND PLATED STEEL MATERIAL AS WELL AS DERUSTING SOLUTION FOR THOSE TEST PIECE

摘要

PROBLEM TO BE SOLVED: To obtain a derusting solution by which rust caused on a steel material or a plated steel material can be removed in a short time while the erosion of substrate iron is being suppressed by a method wherein hydrogen peroxide or the like is added additionally to a derusting solution in which hydrochloric acid and hexamethylenetetramine at specific concentrations are contained. ;SOLUTION: A derusting solution which is used to quantitatively analyze the amount of rust caused on the surface of a test piece is prepared in such a way that 0.1 to 5 wt.% of hydrogen peroxide is added to a derusting solution composed of an aqueous solution which contains 5 to 24 wt.% of hydrochloric acid and 0.1 to 10 g/l of hexamethylenetetramine are contained. Alternatively, a derusting solution which removes rust caused on the surface of a steel material or a plated steel material used for a structure and which restores a beautiful appearance is an aqueous solution in which 5 to 25% of hydrochloric acid, 1.0 to 10 g/l of hexamethylenetetramine and 10 to 200 g/l of ferrous chloride are contained. Alternatively, 0.1 to 5 wt.% of hydrogen peroxide may be contained additionally in the derusting solution. When the beautiful appearance on the surface of the steel material is to be regenerated, the hydrogen peroxide may be added from the beginning.;COPYRIGHT: (C)1999,JPO