Pickling agent containing urea and method of producing it
AssigneeAvestapolarit Aktiebolag (Publ)
InventorsSven-Eric Lunner, Fredrik Hägg
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Abstract
A long-time stable pickling agent for the removal of an oxide layer on a stainless steel after heat treatment, such as welding, which pickling agent comprises nitric acid and fillers and constitutes of a pickling paste or pickling gel to be coated on the heat treated stainless steel, or of a pickling liquid to be sprayed on the steel. According to the invention, the pickling agent also comprises urea for reduced formation of nitrous fumes when the pickling agent is used.
Claims20
A pickling agent for the removal of an oxide layer on stainless steel after heat treatment, such as welding, which pickling agent comprises nitric acid and a filler, said filler comprising a pulverous, inorganic thickener in an amount of 2 to 30 percent by weight, said pickling agent being a pickling paste or pickling gel suitable for coating on the heat treated stainless steel, or a pickling liquid suitable for spraying on the steel, wherein said pickling agent also comprises at least 60 g/l of urea for reduced formation of nitrous fumes during use of the pickling agent, and wherein the pickling agent exhibits long term stability when stored at room temperature.
Dependencies are inferred from the claim text.