Descaling pickling liquid and descaling pickling manner null

摘要

PROBLEM TO BE SOLVED: To provide a descaling pickling method using sulfuric acid or the descaling pickling solution mainly consisting of sulfuric acid for the steel, in particular, the heat-treated steel in which descaling is promoted, erosion of the base metal is suppressed, generation of smut and pitching is prevented, and the smooth and excellent surface can be obtained. ;SOLUTION: The pickling time is shortened, and generation of smut and pitching is greatly reduced by adding ≥1 g/L of thiourea as the descaling promoter to sulfuric acid or the descaling pickling solution mainly consisting of sulfuric acid for steel, and arbitrarily adding the pickling inhibitor less effective in descaling promotion. In order to avoid generation of red iron oxide-like brown smut to be generated in pickling scales on the heat-treated steel, oxy- carboxylic acid, imino-carboxylic acid, or the salt thereof is arbitrarily added as the descaling promotion adjuvant.;COPYRIGHT: (C)1999,JPO