Disclosed are an ionic liquid for pickling a stainless steel capable of rapidly removing oxide scale from the stainless steel at room temperature without using nitric acid or hydrofluoric acid and a method for pickling a stainless steel by using the same. The method for pickling a stainless steel according to an embodiment includes performing electrolytic pickling treatment by immersing a stainless steel in a pickling solution including an ionic liquid, wherein the ionic liquid comprises at least one of an imidazolium cation, a betainium cation, a sulfonium cation, a piperidinium cation, a phosphonium cation, an ammonium cation, a pyridium cation, a pyrrolidinium cation, and a morpholinium cation, as a cationic functional group, and at least one of a halide anion, a sulfonate anion, an alkylsulfate anion, a phosphinate anion, a salicylate anion, a nitrate anion, a tetrafluoroborate anion, a hexafluorophosphate anion, and a bistriflimide anion, as an anionic functional group.

A heterocyclic compound having a structure in which a benzene ring and a nitrogen-containing heterocycle are condensed is added to a sulfuric acid solution that contains a persulfuric acid component such as peroxomonosulfuric acid, peroxomonosulfate, peroxodisulfuric acid, or peroxodisulfate as an oxidant and in which impurities that promote the reduction in the oxidant concentration are present. Here, the heterocyclic compound having a structure in which a benzene ring and a nitrogen-containing heterocycle are condensed is preferably a benzotriazole-based compound. The impurities that promote a reduction in the oxidant concentration are suitably one or more selected from copper ions, iron ions, nitrate ions, and nitrite ions. The method of the present invention of inhibiting a reduction in the oxidant concentration in a sulfuric acid solution containing a persulfuric acid component can inhibit the reduction in the oxidant concentration to a minimum even when impurities that cause a reduction in the oxidant concentration are mixed.

A corrosion inhibitor composition, which includes i) an aqueous alcohol base fluid, ii) a mixture of at least three polysaccharides selected from carboxymethyl cellulose, gum arabic, pectin, a salt of alginic acid, chitosan, dextran, hydroxyethyl cellulose, and soluble starch, with each polysaccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt. %, based on a total weight of the corrosion inhibitor composition, iii) silver nanoparticles, and iv) a pineapple leaves extract. A method of inhibiting corrosion of metal during acid cleaning/pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition.

A corrosion inhibitor composition, which includes i) an aqueous alcohol base fluid, ii) a mixture of at least three polysaccharides selected from carboxymethyl cellulose, gum arabic, pectin, a salt of alginic acid, chitosan, dextran, hydroxyethyl cellulose, and soluble starch, with each polysaccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt. %, based on a total weight of the corrosion inhibitor composition, iii) silver nanoparticles, and iv) a pineapple leaves extract. A method of inhibiting corrosion of metal during acid cleaning/pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition.

A corrosion inhibitor composition, which includes i) an aqueous alcohol base fluid, ii) a mixture of at least three polysaccharides selected from carboxymethyl cellulose, gum arabic, pectin, a salt of alginic acid, chitosan, dextran, hydroxyethyl cellulose, and soluble starch, with each polysaccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt. %, based on a total weight of the corrosion inhibitor composition, iii) silver nanoparticles, and iv) a pineapple leaves extract. A method of inhibiting corrosion of metal during acid cleaning/pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition.

Provided is an acid-pickling additive for a surface oxide scale of a stainless steel material, a preparation method thereof and an acid-pickling method. The acid-pickling additive consists of 1 to 10 parts by weight of an alcohol amine compound, 0.1 to 5 parts by weight of a metal complex ligand, 0 to 10 parts by weight of a nitrogen-containing organic cyclic compound, 0 to 3 parts by weight of an alcohol compound, 0 to 3 parts by weight of a plant extract, and 1 to 2 parts by weight of water. This acid-pickling additive can solve the problems of high energy consumption, environmental pollution, and high cost in the existing method for removing an oxide scale of a stainless steel.

The invention relates to cleaning deposits of various natures from metal, glass and ceramic surfaces of industrial equipment and can be used for the removal of such deposits, as metal oxides (iron, chromium, nickel, etc.), carbonate and salt deposits, asphalt-tar-paraffin deposits and deposits of an oily nature, deposits of organic and biological nature (bacterial deposits). The proposed solution for removing deposits of different natures comprises hydrogen peroxide, complexing agent, calixarene and water in the following quantitative ratio, wt. %: hydrogen peroxide, 2-90; complexing agent, 3-30; calixarene, 0.01-10; water, the balance. EFFECT: increased degree of cleaning off deposits of various natures with simultaneous reduction of solution aggressiveness to structural materials.

Disclosed are metal cleaning formulations and methods of use. A formulation of the present teachings comprises one or more furoate esters such as ethyl 5-methyl-2-furoate and methyl 5-methyl-2-furoate. The formulations further comprise a base oil, which can be, for example, a naphthenic oil, a synthetic oil or a combination thereof. In some embodiments, a formulation can further comprise a metal protection additive and a lubrication additive. A variety of base oils, metal protection additives, and lubrication additives are suitable for use in the present teachings. Formulations of the present teachings are especially useful for the cleaning of metal products such as firearms. The cleaning power of a formulation of the instant teachings can exceed that required for US Military Specifications.

A corrosion inhibitor composition, which includes i) an aqueous alcohol base fluid, ii) a mixture of at least three polysaccharides selected from carboxymethyl cellulose, gum arabic, pectin, a salt of alginic acid, chitosan, dextran, hydroxyethyl cellulose, and soluble starch, with each polysaccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt. %, based on a total weight of the corrosion inhibitor composition, iii) silver nanoparticles, and iv) a pineapple leaves extract. A method of inhibiting corrosion of metal during acid cleaning/pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition.

The invention relates to cleaning deposits of various natures from metal, glass and ceramic surfaces of industrial equipment and can be used for the removal of such deposits, as metal oxides (iron, chromium, nickel, etc.), carbonate and salt deposits, asphalt-tar-paraffin deposits and deposits of an oily nature, deposits of organic and biological nature (bacterial deposits). The proposed solution for removing deposits of different natures comprises hydrogen peroxide, complexing agent, calixarene and water in the following quantitative ratio, wt. %: hydrogen peroxide, 2-90; complexing agent, 3-30; calixarene, 0.01-10; water, the balance. EFFECT: increased degree of cleaning off deposits of various natures with simultaneous reduction of solution aggressiveness to structural materials.