Benefits from improved bath agitation with the RADEX DPP gas purging system during EAF highalloyed and stainless steel production

Modern production processes of high alloyed and stainless steel grades are subject to the cost-optimized production of raw steel or molten combined with high flexibility. Excellent mixing of the steel melt helps to improve mass and heat transfer in the EAF, in order to accelerate the melting of heavy scrap and alloys, decarburization, homogeneous superheating, alloy distribution, and to avoid skull formation and solid remainders that may obstruct tapping. The RADEX DPP system generates customer benefits by improving EAF processes during high-alloyed stainless steel making. The most important effect of the enhanced steel bath mixing besides improved heat transfer and decarburization is a decreased chromium oxidation. Firstly, chromium oxidation is decreased by improving the homogeneous distribution of carbon and chromium in the melt. Secondary, build-up of chromium-containing solids in the EAF hearth and skull formation is decreased by stronger melt movement. The cost savings of both effects economically justify the application of gas purging in EAF stainless steelmaking. Case studies are presented demonstrating the advantages. Ill.7. Ref. 7. Tab. 3.

Плавление и электромиграция в тонких пленках хрома

Chromium films with a thickness of 10–40 nm deposited onto silicon substrates by magnetron sputtering are subjected to the action of electric current induced by the tip of an atomic force microscope (AFM) cantilever in air under regular environmental conditions. The melting process at the nanoscale, electric field-induced migration of material, and the chemical reaction of chromium oxidation that occur in melt craters formed around the region affected by the current are investigated using optical and scanning electron microscopies, AFM, and Raman spectroscopy. The flow of melted material induced by electric current is accompanied by the formation and motion of an array of spherical nanoparticles in the melt crater along its periphery. We propose that the formation of nanodrop array at relatively low current densities can be explained by the chromium oxidation reaction and the surface tension of melted material on the silicon substrate.