Abstract: Resistance of iron, iron-chromium and iron-chromium-nickel alloys to corrosive attack by sulfur compounds at temperatures above 500.degree. F. is improved by pretreating the metal under controlled conditions to form an extremely thin submicroscopic oxide film which serves as a corrosion resistant barrier.

Abstract: Hydrocarbon liquids having a pH greater than 7 are inhibited against corrosion by the addition thereto of a corrosion inhibiting amount of a diamide or mixture of diamides of 1,3-dipropylene triamine and one or more organic monocarboxylic acids containing a sufficient number of carbon atoms to render said diamide or mixture of diamides oil soluble and water insoluble.

Abstract: A method of preventing corrosion of steelworks by a flowing corrosive solution having a pH of 6.7 to 7.1 and comprising water, ammonia in a concentration of from 0.5 to 4 mols per liter of solution and hydrogen sulfide in a concentration of from 5 to 15 kg/cm.sup.2 as its partial pressure in the vapor phase, said corrosive solution contacting said steelwork at a flow velocity of from 1 to 10 meters per second by adding at least one substance selected from the group consisting of elemental sulfur, ammonium polysulfide and alkali polysulfide to said corrosive solution in an amount of 74-200 ppm as the amount of available sulfur.

Abstract: Anticorrosive agent based on saponified ene-adducts of maleic anhydride to unsaturated fatty acids or derivatives thereof.

Abstract: A method for the inhibition of metal scale formation in a hydrocarbon processing unit prior to catalyst loading and start-up comprising the steps: circulating a gas comprising a sulfiding component; heating the hydrocarbon conversion zone to at least hydrocarbon conversion temperature; and, collecting loosely bound metal scale until scale production abates. The recurring problem of catalyst bed inlet plugging is solved by removing indigenous metal scale, dust and debris and by passivating the virgin metallic surfaces before the initial start-up of a hydrocarbon processing unit.

Abstract: Oil dispersible ferrous metal corrosion inhibitors are prepared by first forming a primary amine-terminated amide adduct by reacting a mixture of monomeric, dimeric and trimeric 1,6-hexanediamine with polyfunctional acids at a ratio of reactants such that the adduct is substantially completely terminated with primary amine groups and neutralizing the primary amine-terminated amide adduct with a carboxylic acid. Alternatively, water dispersible adducts may be prepared by reacting the primary amine-terminated amide adduct with an oxirane compound to produce a polyether derivative of the amine-terminated adduct.