The invention belongs to the field of stainless steel
pickling, and particularly relates to an
austenitic stainless steel whole-hydrochloric-acid-based stepped
pickling method. At present, stainless steel
pickling is mainly based on a mixed acid pickling (
nitric acid and
hydrofluoric acid)
system, the problem of three-waste
discharge exists in the pickling process, the pickling process is only suitable for removing ferritic stainless steel with
weak binding force between an
oxide layer and a
metal matrix through pickling, and the
oxide layers on the surfaces of ferritic
cold plate stainless steel and
austenitic stainless steel are difficult to remove. In order to solve the problems,
hydrochloric acid is used for providing an acid environment, a pre-pickling and grading final pickling cooperative treatment method is adopted, a compact
oxide layer on the surface of the
austenitic stainless steel can be effectively removed, surface
polishing and surface
passivation can be achieved through the anodic polarization effect, and the stainless steel surface after pickling is free of
pitting corrosion and
intergranular corrosion phenomena; and the pickled stainless steel surface has high smoothness, the leveling and
polishing quality of the BA plate can be remarkably improved, meanwhile, the production cost is low, and pickling waste liquid can be regenerated and recycled.