Evolution of Chemical Composition and Modeling of Growth Nonmetallic Inclusions in Steel Containing Yttrium

The programs WYK_Stal and Bi-Growth, developed at AGH-UST, Kraków, Poland, were used for simulating the refining process, the formation of non-metallic inclusions, and their growth. The Fe-Y-Al-O-S-Ca system in pre-oxidized steel was analyzed, where yttrium formed precipitates from both O and S. When first Al and second Y were added to steel, the proportion of Al2O3 inclusions remained constant. This resulted in higher yttrium losses for oxide formation, whereas the sulfur content promoted sulfide phase formation. The introduction of yttrium at the end of refining contributed to reducing the consumption of this element in the non-metallic phase formation. The addition of aluminum and then calcium were sufficient to achieve a high degree of deoxidation and desulfurization. Calculations performed with WYK_Stal for both (a) and (c) versions of the model showed that the sulfide phase was constituted by CaS and FeS (model c) and CaS (model (a)). The participation of the calcium sulfide phase turned out to be dominant in the inclusions. Their presence was also identified in the slag phase. Simulations of the growth of complex oxide and oxo-sulfide inclusions using the Bi_Growth program showed that the yttrium content of the steel has a decisive role in the formation of complex oxide inclusions and the final oxygen content of the steel. In contrast, for the growth of oxide-sulfide inclusions, the character of growth is determined by the sulfur content of steel.

RESEARCH OF THE METAL WORKING IN THE ENVIRONMENTS CAUSING SODIUM HYDROGEN CRACKING

The results of a study of a metal working in environments causing hydrogen sulfide cracking are presented. The previously studied steels were induced in a hydrogen sulfide-containing medium under the action of tensile stresses in the metal of the samples. It has been established that characteristic defects in the form of bubbles and blisters are formed on the surface of metals. A study of microstructures showed that cracks originate at the boundary between pearlite and ferrite grains and on the streaked sulfide phase of the FeS · MnS type. Disclosure of the boundary of pearlitic and ferrite grains is due to their surface contamination with microimpurities. The results of the analysis for inclusions show that 20YuCH steel is much cleaner in inclusions than American steel of the type steel 20, and sulfides are more dispersed and coagulated, while a significant part of the sulfur is bound by cerium. This explains the best resistance of steel 20YUCH against hydrogen sulfide cracking.

Plasma driven nano-morphological changes and photovoltaic performance in dye sensitized 2D-layered dual oxy-sulfide phase WS2 films

The presence of a dual oxy-sulfide phase and its effects on photovoltaic performance were observed in dye sensitized 2D layered WS2 films.

Effects of Machining History on Tribological Properties of Bronze Containing Micro-Sized Sulfide

Bronze based alloys have come to be used as bearing materials, and require low frictional properties. The present study describes the effects of surface finish machining history on the on tribological properties of sulfide-containing bronze sintered onto a steel disc. The sulfide phase consisted of copper, iron and sulfur, and acted as a solid lubricant. The relative density of the specimen was 90 % and the microstructure showed that the micro-sized sulfide dispersed into the bronze matrix and was accompanied by pores. Various processes, including cutting, burnishing, polishing were, applied to finish the surface. It was found that the area fraction of the sulfide phase depended on the cutting conditions. A further increase in the area fraction was achieved using roller burnishing after the cutting. Tribological properties were evaluated using chromium alloy steel (SUJ2) as the mating surface under dry conditions. The results showed that the friction coefficient depended on the surface finishing process. Therefore, the machining history had an effect on the frictional properties of the sulfide-containing bronze. Optimal cutting conditions for the sulfide containing bronze are also discussed.

The Study of Fluid Inclusions in Haoyaoerhudong Gold Deposit

Haoyaoerhudong gold deposit is located in Inner Mongolia Wulate county. We analysis the characteristics of fluid composition. Salinity values range is from 3.40% to 20.40%; The density of the fluid is from 0.68 to 0.97 g/cm3;Ore-forming pressure is from 11.44 to 58.42MPa;According them, We can separate the fluid into Quartz-pyrite stage, Ore-forming fluid is divided into four stages in Haoyaoerhudong gold deposit. It is quartz calcite phase, the late stage of quartz vein, quartz polymetallic sulfide phase and quartz Pyrite phase. Quartz polymetallic sulfide phase and quartz Pyrite phase is the main metallogenic period in Haoyaoerhudong gold deposit.