Compounds, compositions and methods are provided for inhibiting corrosion at a surface in the production, transportation, storage, and separation of fluids such as crude oil and natural gas, the compounds having the formula: ##STR00001## wherein: Each R.sub.1 is independently —CH.sub.2OH and —C(O)OH; R.sub.2 is ##STR00002## Each R.sub.3 is independently hydrogen or R.sub.5, or both R.sub.3 together form a ring via a linker ##STR00003## Each R.sub.4 is independently hydrogen or R.sub.5; R.sub.5 is —CH.sub.2SC.sub.2H.sub.4R.sub.1; and n is an integer from 0 to 3.

A method is disclosed for welding a first part and second part together. A spacer bead is first formed on the first part by directing a laser beam on one side of the first part. The second part is then assembled to the one side of the first part. The second part is then welded to the first part by directing a second laser beam in a partially circular pattern adjacent the spacer bead. An end portion of the weld terminates radially inside the partially circular pattern.

Methods of inhibiting corrosion in a benzene distillation or dryer unit are provided wherein alkenyl succinic acids or anhydrides (ASA) are brought into contact with metal surfaces thereby protecting the metal from an acidic corrosive medium flowing through the overhead. The benzene distillation column or drying tower may be utilized to purify benzene for subsequent feed of the purified benzene to an alkylation process such as in the alkylation of benzene by ethene to form ethylbenzene utilizing a zeolite alkylation catalyst.

Technologies are presented for reducing corrosion M supercritical water gasification through seeded sacrificial metal particles. The metal panicles may be seeded into one or more material input streams through high pressure injection. Once distributed in the SCWG reactor, the metal particles may corrode preferentially to the metal SCWG reactor walls and convert into metal oxides that precipitate out above the supercritical point of water. The precipitated metal oxides may then be collected downstream of the SCWG reactor to be reprocessed back into seed metal at a smelter. The seeded metal particles may complete a process material cycle with limited net additional waste.

Pitting corrosion of stainless steel occurs in solutions of organic acid, such as tartaric acid, in an electrolyte solution with methanol. However, methanolic solutions containing at least one organic halide and at least one organic hydroxyacid and some water provide reduced pitting corrosion of stainless steel. The organic hydroxyacid may be a hydroxy acid containing 2 to 10 carbon atoms with at least one hydroxyl group and at least one carboxylic acid group, in a non-limiting example, glycolic acid. The pH of the methanolic solution may range from about 3.5 to about 8.

Corrosion inhibition systems, including coated substrates, coating materials and corrosion inhibition compounds, and methods of making the same are disclosed. These systems and methods include corrosion inhibition compounds that are responsive to corrosion at a surface, releasing active inhibitor groups upon a corrosion stimulus. The active inhibitor groups are selected to block corrosion at the surface by inhibiting oxidation reactions, reduction reactions and/or by forming a passivation layer.

The invention provides a film-forming composition containing a tannic acid derivative in which hydrogen atoms in at least some of hydroxyl groups of tannic acid are substituted by a chain hydrocarbon group having 3 to 18 carbon atoms. The film-forming composition of the invention can provide a good enough film on a variety of substrate materials, having improved effects on rust prevention or the like.

The invention provides a film-forming composition containing a tannic acid derivative in which hydrogen atoms in at least some of hydroxyl groups of tannic acid are substituted by a chain hydrocarbon group having 3 to 18 carbon atoms. The film-forming composition of the invention can provide a good enough film on a variety of substrate materials, having improved effects on rust prevention or the like.

A method for producing a thermoplastic fiber composite component, in particular for an aircraft or spacecraft, has the following method steps: material-removing processing of a first face of a first plate, wherein the first plate comprises a thermoplastic fiber composite material and a local reduction in thickness of the first plate is made by the material-removing processing of the first face; positioning a second plate relative to the first plate such that the first face of the first plate is brought into alignment with a third face of the second plate; and joining the first plate to the second plate to form a single component, wherein the surface of the first face of the first plate is integrally bonded to the surface of the third face of the second plate.

A method for producing a thermoplastic fiber composite component, in particular for an aircraft or spacecraft, has the following method steps: material-removing processing of a first face of a first plate, wherein the first plate comprises a thermoplastic fiber composite material and a local reduction in thickness of the first plate is made by the material-removing processing of the first face; positioning a second plate relative to the first plate such that the first face of the first plate is brought into alignment with a third face of the second plate; and joining the first plate to the second plate to form a single component, wherein the surface of the first face of the first plate is integrally bonded to the surface of the third face of the second plate.