| 摘要 |
The invention relates to a method for pickling martensitic or ferritic high-grade steel, preferably in the form of wire, tubes or rods. According to the inventive method, the high-grade steel is contacted with a pickling solution that has a temperature in the range of from 15 to 29 DEG C and that contains 50 to 120 g/l free sulfuric acid, 5 to 40 g/l free HF and 5 to 40 g/l Fe(III) ions. The invention also relates to a process sequence for treating the surfaces of martensitic or ferritic high-grade steel. The sequence comprises the following steps: a) subjecting the high-grade steel to a treatment that breaks up oxidic coatings, preferably by sand-blasting or shot-blasting, a treatment with molten salt or a treatment with an aqueous permanganate/alkalihydroxide solution, b) pickling it according to the method defined in one or more of claims 1 to 6, and c) post-treating it with a passivating solution.
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