Sulfur metal corrosion

Corrosion inhibitor Two inhibitors could be used a. Copper corrosion inhibitor to help prevent sulfur, hydrogen sulfide, and mercaptan attack on copper b. Ferrous metal corrosion inhibitor to prevent water/oxygen initiated corrosion of iron and steel system components... 

Sulfur is limited to 0.05 wt%. Sulfur degrades the efficiency of antiknock compounds and can lead to metal corrosion. 

Jet fuel sulfur normally ranges from 0.20 to 0.40 wt%. Metal corrosion may result when high-sulfur fuel is burned. Mercaptan sulfur is limited to <50 ppm. Odor, elastomer degradation, and corrosion toward metals result from high mercaptan levels. 

During the processing of fuels, acids such as sulfuric acid and hydrofluoric acid are used. Sulfuric acid can be used to polymerize fuel olefins and remove components from fuel such as mercaptans and thiophenes. Sulfuric and hydrofluoric acids are used in the alkylation process to produce high-octane, branched paraffins. Carryover of these acids into fuel can initiate ferrous metal corrosion. 

Sulfuric acid is a stronger acid than sulfurous [pAa(l) < 0, p7fa(2) = 1.99 at 25 °C and infinite dilution] rain as acidic as pH 2.1 has been recorded at Hubbard Brook, New Hampshire, and the pH of water droplets in clouds can be as low as 1.5 (for comparison, the pH of rainwater saturated with atmospheric CO2 is about 5.6 at 15 °C). Acid rain destroys building materials (especially marble), kills fish and vegetation, accelerates metallic corrosion (Sections 16.5 and 16.7), and can be directly harmful to humans (e.g., it causes the alligator skin condition reported in Cubatao, Brazil). Sulfate rain is not completely without redeeming features, as many soils (e.g., in southern Alberta, Canada) are sulfur-deficient. On balance, however, its acidity is unacceptable, and sulfur oxide emissions must be controlled at the source. Several control measures are possible ... 

Additives have been shown to effect decreases in coke deposits. Small amounts of organometallic compounds and commercial fuel-oil additives have been shown to decrease coke weight. Metallic compounds in excess can result in increased deposition because of the metal oxide, and some of these compounds have also been reported to cause metal corrosion, as have sulfur compounds. Results of investigations with additives to inhibit coke formation are not conclusive enough at present to justify their acceptance. 

Physical/chemical changes due to exchange with other surrounding packaging materials (e.g., metal corrosion due to sulfur-based paper). 

Metallic Corrosion of Sulfur and Its Con unds, Z. A. Foroulis, Ed., The Electrochemical Society, New York, 19/0. 

Isobutane and light olefins are the desired hydrocarbon feeds. Unfortunately, impurities such as acetylenes, dienes, sulfur- and oxygen-containing hydrocarbons, cyclopentene, and water are also often present. Purification of the feeds is expensive, but is sometimes cost-effective as a means of reducing the buildup in the acids of conjunct polymers. Dry hydrocarbon feeds are preferred, especially with HE. The water transfers to the HE and is a concern relative to metal corrosion. Solid adsorbents are often used for drying of feedstocks. 

Incompatibilities and Reactivities Strong oxidizers, ammonia solutions [Note Decomposes in water to sulfuric acid corrosive to metals.] ... 

Schmitt [52] reviewed the effect of elemental sulfur on corrosion of construction materials (carbon steels, ferric steels, austenitic steels, ferritic-austenitic steels (duplex steels), nickel and cobalt-based alloys and titanium. Wet elemental sulfur in contact with iron is aggressive and can result in the formation of iron sulfides or in stress corrosion cracking. Iron sulfides containing elemental sulfur initiate corrosion only when the elemental sulfur is in direct contact with the sulfide-covered metal. Iron sulfides are highly electron conductive and serve to transport electrons from the metal to the elemental sulfur. The coexistence of hydrogen sulfide and elemental sulfur in aqueous systems, that is, sour gases and oils, causes crevice corrosion rates of... 

Determination of resistance to intergranular corrosion of stainless steels—Part 2 Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels—Corrosion test in media containing sulfuric acid Corrosion of metals and alloys— Determination of dezincification resistance of brass Copper alloys— Ammonia test for stress corrosion resistance Corrosion tests in artificial atmosphere—General requirements... 

Atmospheric corrosion is a complicated electrochemical process taking place in corrosion cells consisting of base metal, metallic corrosion products, surface electrolyte, and the atmosphere. Many variables influence the corrosion characteristics of an atmosphere. Relative humidity, temperature, sulfur dioxide content, hydrogen sulfide content, chloride content, amount of rainfall, dust, and even the position of the exposed metal exhibit marked influence on corrosion behavior. Geographic location is also a factor. 

I. Epelboin, M. Keddam, and P. Morel, Evidence of multi-step reactions on iron, nickel and chromium electrodes immersed in a sulfuric acid solution, Proceedings 3rd Congress Metal Corrosion, Moscow, 1966, p. 110. 

In the first sections of this chapter, the basic effects of adsorbed sulfur on anodic dissolution, on passivation, and on the breakdown of passive films are presented. In a subsequent section the effects of alloyed elements (essentially Cr and Mo) are presented and the way in which they can counteract the detrimental influence of sulfur is emphasized. In the next section, implications of the mechanisms of sulfur-induced corrosion for different areas of practical importance are given, with connections to the related chapters of this book. In the last section of this chapter, the thermodynamic predictions of the conditions of adsorption of sulfur on metal surfaces in water are given. 

There is much evidence for the damaging effect of sulfur species in a wide range of corrosion-related service failures. The relation between the sulfur-induced corrosion mechanisms presented in this chapter and the implications in areas of practical importance can be rationalized on the basis of (a) the source of sulfur, (b) the transport process to the metal surface, and (c) the conditions of the reduction (or... 

Fontana, M.C. (1968). Corrosion by Sulfuric Acid. Corrosion Course Module 14, Metals Engineering Institute, ASM. 

The refining industry generally seeks either to eliminate asphaltenes or to convert them to lighter materials because the presence of heteroelements cause pollution problems, e.g., sulfur and nitrogen, catalyst poisoning, and corrosion (formation of metal vanadates during combustion). 

Pure vanadium is a bright white metal, and is soft and duchle. It has good corrosion resistance to alkalis, sulfuric and hydrochloric acid, and salt water, but the metal oxidizes readily above 660oC. 

Lead is a bluish-white metal of bright luster, is very soft, highly malleable, ductile, and a poor conductor of electricity. It is very resistant to corrosion lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. It is used in containers for corrosive liquids (such as sulfuric acid) and may be toughened by the addition of a small percentage of antimony or other metals. 

Technetium is a silvery-gray metal that tarnishes slowly in moist air. The common oxidation states of technetium are +7, +5, and +4. Under oxidizing conditions technetium (Vll) will exist as the pertechnetate ion, TcOr-. The chemistry of technetium is said to be similar to that of rhenium. Technetium dissolves in nitric acid, aqua regia, and cone, sulfuric acid, but is not soluble in hydrochloric acid of any strength. The element is a remarkable corrosion inhibitor for steel. The metal is an excellent superconductor at IIK and below. 

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