Sulfide inclusions

Sulfide inclusions have been identified as the origins of pits and stress-corrosion cracks in stainless steel stmctures under some conditions (see... 

Figure 53.3 illustrates a pit in a stainless steel such as type 534 or 316 austenitic alloy. Pitting starts at heterogeneity in the steel surface, such as an outcropping sulfide inclusion, the shielded region beneath a deposit or even a discontinuity in the naturally present oxide film caused by a scratch or embedded particle of abrasive grit. This initiation phase of pitting corrosion may take seconds... 

Host Sulfide Inclusion complex From complex From filtrate ... 

We have analysed 14 samples of contact-style ore from Creighton Mine comprising disseminated ores (< 30% sulfides), inclusion-bearing ores (containing fragments of the norite) and massive ores (> 80% sulfides). The ores contain on average 75% pyrrhotite, 17% pentlandite and 8% chalcopyrite. Chalcopyrite content varies from 0-25%. 

Sulfur occurs in a variety of forms in the mantle, the major sulfur phase is monosulfide solid solution between Fe, Ni, and Cu. Recent ion microprobe measurements on sulfide inclusions from megacrysts and pyroxenite xenohths from alkali basalts and kimberlites and in diamonds gave 5 " S-values from — 11 to - - 14%c (Chaussidon et al. 1987, 1989 Eldridge et al. 1991). Sulfur isotope variations within diamonds exhibit the same characteristics as previously described for carbon i.e., eclogitic diamonds are much more variable than peridotitic diamonds. 

Farquhar J, Wing B, McKeegan KD, Harris JW (2002) Insight into crust-mantle coupling from anomalous A S of sulfide inclusions in diamonds. Geochim Cosmochim Acta Spec Suppl 66 ... 

Replacement of rare earth elements for sulfide inclusion shape oontrpl 1 extreme steel desulfurization with the aid of calcium. 

Figure 4. Hot plasticity of sulfide inclusions during hot rolling of steel as a function of oxygen content, Mn/S ratio, rolling temperatures, and substitution by stronger sulfide formers. The hot plasticity is measured in length-to-width ratio of elongation after hot rolling, in longitudinal sections.

Figure 5. Elongated manganese sulfide inclusion in aluminum killed steel after hot...

What happened The German and Japanese steel metallurgists had understood much earlier in the game, during the sixties, the paramount importance of eliminating the manganese sulfide inclusions. Their equipment and highly quality-oriented minds allowed them to tackle the difficult orders ahead of everybody else. 

Luyckx, L. "Sulfide Inclusions in Steel", American Society for Metals, Metals Park, OH, 1975, p. hh-69. 

Figure 2.25 SEM view of the fracture surface of a low-carbon steel specimen broken in tension, showing ductile dimples, local quasicleavage, and manganese sulfide inclusions. (Reprinted with permission from ASM International. All rights reserved www.asminternational.org)...

Misch metal or rare earth silicon alloy for controlling shapes of sulfide inclusions and thereby improving transverse impact strength... 

Convincing evidence of recycling of volatiles to the mantle and their incorporation into diamonds has recently been reported from sulfur isotope studies of sulfide inclusions within diamond (Farquhar et al., 2002). SIMS analysis of sulfide inclusions has revealed anomalous mass-indepen-dently fractionated sulfur isotopic compositions from the Orapa kimberlite, which are explained as a consequence of the recycling of surface sulfur produced through photolytic chemistry in the Archean atmosphere. Such studies need to be extended to other diamond populations and combined with C-N isotope studies on the host diamonds. 

Until the application of the Re-Os isotopic system to whole-rock peridotites (Section 2.05.2.7.4) the Archean and Proterozoic Pb-Pb and Sm-Nd model ages and isochrons obtained on diamonds were the chief constraints on the antiquity of the continental hthospheric mantle (Kramers, 1979 Richardson et al, 1984). Early work, most of which was on diamonds from the Kaapvaal-Zimbabwe craton because of sample availability, suggested a simple difference from Meso-Archean P-type (harzburgitic) diamonds and Proterozoic E-type diamonds (Richardson, 1986 Richardson et al, 1984, 1993). More recent Re-Os work on single sulfide inclusions from the Kaapvaal-Zimbabwe craton has underscored the importance of a Neo-Archean E-type diamond... 

Chaussidon M., Albarede F., and Sheppard S. M. F. (1989) Sulfur isotope variations in the mantle from ion-microprobe analyses of micro-sulfide inclusions. Earth Planet. Sci. Lett. 92, 144-156. 

Deines P. and Harris J. W. (1995) Sulfide inclusion chemistry and carbon isotopes of African diamonds. Geochim. Cosmochim. Acta 59(15), 3173-3188. 

Pearson D. G., Shirey S. B., Bulanova G. P., Carlson R. W., and Milledge H. J. (1999a) Re-Os isotope measurements of single sulfide inclusions in a Siberian diamond and its nitrogen aggregation systematics. Geochim. Cosmochim. Acta 63(5), 703 -711. 

Bulanova G. P., Griffin W. L., Ryan C. G., Shestakova O. Y., and Barnes S.-J. (1996) Trace elements in sulfide inclusions from Yakutian diamonds. Contrib. Mineral. Petrol. 124, 111-125. 

Peterson R. and Francis D. (1977) The origin of sulfide inclusions in pyroxene megacrysts. Am. Mineral. 62, 1049-1051. 

Rudnick R. L., Eldridge C. S., and Bulanova G. P. (1993a) Diamond growth history from in situ measurement of Pb and S isotopic compositions of sulfide inclusions. Geology 21, 13-16. 

Studies of the sulfide inclusions in diamonds have given some indications of sulfur cycling on the Archean earth. These inclusions often appear to be enriched in which has been interpreted as indicative of photolysis of volcanic SO2 at wavelengths <193 nm. This photolysis yields elemental sulfur enriched in while the oceanic sulfate was depleted in (see Eigure 4). The elemental sulfide becomes incorporated into sulfides and can be subducted, and included in diamonds. By contrast seawater has sulfates depleted in and gave Archean barites that are also depleted in the While such studies offer an indication of the sulfur cycle in the Archean, they can also offer insight into the nature of mantle convection through time (Earquhar et ah, 2002). 

Fission products that are compatible with the uraninite crystal stmcture—the REE, yttrium, neodymium, and zirconium—were largely retained in the uraninite core, the reactor clays, minor phosphate phases, and uranium and zirconium silicate phases (Gauthier-Lafaye et ai, 1996). Lighter REE—lanthanum, cerium, and praseodymium—were partially lost from the reactor. Einally, molybdenum, technetium, mthe-nium, rhodium, and other metallic elements were retained in the metal/metal oxide inclusions and arsenide/sulfide inclusions in the core, and in the reactor clays (Hidaka et ai, 1993 Jensen and Ewing, 2001). 

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