A concentrate aqueous composition for removing Type I and Type III rouge from various stainless-steel items. The liquid composition comprises oxalic acid, a phosphonic acid, and various amines. The use of an amine has been found to provide synergistic results in removal of the noted types of corrosion from various stainless-steel items that include medical instruments, machines, equipment, pipes, tools, mixing and storage vessels, and the like.

The present disclosure relates to compositions and methods for the removal of deposits from oilfield apparatus and wellbore surfaces. In particular, removal of deposits comprising heavy hydrocarbon materials and finely divided inorganic solids. The composition includes a mixture of a corrosion inhibitor component which is morpholine or a morpholine derivative having corrosion inhibitor properties, and a surfactant which is a quaternary ammonium compound having biocidal properties. Methods of removing a deposit from a surface or unplugging an oilwell which has been plugged with a deposit, are also included wherein the method comprising contacting the deposit with a composition as disclosed herein for a selected period of time.

A film forming apparatus is connected to a carbon steel purification system piping of a BWR plant (S1). Formic acid (surface purification agent) is injected into a circulation piping of the film forming apparatus (S4). A surface purification agent aqueous solution containing 30000 ppm of formic acid is contacted with the inner surface of the purification system piping, and a large amount of Fe.sup.2+ is dissolved from the purification system piping, and a large amount of electrons are generated by this dissolution. Thereafter, a formic acid Ni aqueous solution is injected into the surface purification agent aqueous solution to produce a film forming aqueous solution (S5). The film forming aqueous solution storing the electrons is contacted with the inner surface of the purification system piping, and Ni ions incorporated into the inner surface are reduced by the electrons, and a Ni metal film is formed on the inner surface. Platinum ions and a reducing agent are injected into the circulation piping (S9, S10), and an aqueous solution containing the platinum ions and the reducing agent is supplied to the purification system piping to deposit platinum on the surface of the Ni metal film.

An aqueous synthetic acid composition for use in oil industry activities, said composition comprising: lysine and hydrogen chloride in a molar ratio ranging from 1:3 to 1:12.5, preferably from more than 1:5 to 1:8.5; it can also further comprise a metal iodide or iodate; an alcohol or derivative thereof Said composition demonstrates advantageous properties over known synthetic acids at temperatures above 90 C. Said composition is useful in various oil and gas industry operations. Preferred embodiments of said composition providing substantial advantages in matrix acidizing by increasing the effectiveness of wormholing compared to conventional mineral acids such as HC1.

An aqueous synthetic acid composition for use in oil industry activities, said composition comprising: lysine and hydrogen chloride in a molar ratio ranging from 1:3 to 1:12.5, preferably from more than 1:5 to 1:8.5; it can also further comprise a metal iodide or iodate; an alcohol or derivative thereof Said composition demonstrates advantageous properties over known synthetic acids at temperatures above 90 C. Said composition is useful in various oil and gas industry operations. Preferred embodiments of said composition providing substantial advantages in matrix acidizing by increasing the effectiveness of wormholing compared to conventional mineral acids such as HCl.

Provided herein is a reductive solution for preventing rouge formation on stainless steel, said solution comprising complexing anions, Fe.sup.2+, and, optionally, one or more pH modifiers. Further provided are methods for manufacturing said solution, methods for prevention of rouge formation on stainless steel surfaces, and related uses of the aforementioned reductive solution.

The present invention relates to a composition of at least one sulfonic acid in combination with an effective amount of at least one nitrosyl compound, acting as inhibitor of corrosion of metals by said at least one sulfonic acid.

A method for manufacturing a high-strength galvanized steel sheet having excellent strength-elongation balance, coating adhesiveness, and surface appearance. The method includes: (i) a first heating process of heating a steel sheet having a predetermined chemical composition, (ii) a first pickling process of pickling the steel sheet which was subjected to the first heating process in an oxidizing acidic aqueous solution, (iii) a second pickling process of pickling the steel sheet which was subjected to the first pickling process in a non-oxidizing acidic aqueous solution, (iv) a second heating process of holding the steel sheet, which was subjected to the second pickling process, at a temperature range of 700 C. or higher and 900 C. or lower in a hydrogen-containing atmosphere for 20 seconds or more and 300 seconds or less, and (v) performing a galvanizing treatment on the steel sheet which was subjected to the second heating process.

A cleaning solution for a turbine engine includes water within a range between about 68.65 percent and about 99.63 percent by volume of the cleaning solution; a first organic acidic component within a range between about 0.1 percent and about 15 percent by volume of the cleaning solution; wherein the organic acid comprises citric acid; a second organic acidic component within a range between about 0.1 percent and about 15 percent by volume of the cleaning solution; wherein the organic acid comprises glycolic acid; isoropylamine sulphonate within a range between about 0.07 percent and 0.14 percent by volume of the cleaning solution; alcohol ethoxylate within a range between about 0.035 percent and 0.07 percent by volume of the cleaning solution; triethanol amine within a range between about 0.035 percent and 0.07 percent by volume of the cleaning solution; sodium lauriminodipropionate within a range between about 0.03 percent and 1.0 percent by volume of the cleaning solution. The cleaning solution has a pH value in the range between about 2.5 and about 7.0.

A method of removing mineral scales from a substrate with minimized corrosion of the substrate includes the steps of providing an acid solution providing a corrosion inhibitor solution, applying the acid solution to the substrate to remove mineral scales therefrom, and applying the corrosion inhibitor solution to the substrate to minimize corrosion thereof. The acid solution includes a mineral acid, an organic acid, or a combination thereof. The corrosion inhibitor solution includes an alpha-beta unsaturated aldehyde, a hydrophobic amine, and an oxime. The corrosion inhibitor solution optionally includes formic acid, a surfactant, and a solvent.