Technical solutions for efficiency increasing of blast furnace casting yards aspiration

Casting yards of blast furnaces are most powerful sources of atmospheric air pollution among big non-organized pollution sources of steel industry. The task to create effective systems of those sources aspiration is rather actual.Analysis of known technical solutions on blast furnace casting yards aspiration presented. Positive and negative sides of the projects determined. A conclusion made that aspiration systems effectiveness is determined by designs of local suction facilities and covers for localization of emitted dust and gas convection flows. Main directions of effective aspiration system creation formulated. At the example of JSC MMK BFs No. 9 and No. 10, four variants of technical solutions of general aspiration system for casting yards quoted, accompanied by calculation of convection flows and emissions volumes, maximum necessary productivity of aspiration facility and aero dynamical calculation of an aspiration system. Plan and algorithms of the system valves operation studied. Effectiveness of localization (capture degree) of non-organized emissions estimated as about 90%.

Inhibition Mechanism of Crystal Crack in Copper Thick Plate He-GTA Welding by Adding Deoxidant Element Ti

He-GTA welding of 10mm thick copper plates by using independent developed welding material - CuTi alloys was investigated. The crystal crack induced by eutectic of Cu and Cu2O is disappeared completely as the addition of deoxidant element Ti. It can be concluded that the Ti inhibits the formation of Cu2O and combines with O to generate TiO2through the thermal dynamical calculation. As the TiO2has the characteristic of high molt point and low density, TiO2flows upward to surface of molten pool during welding and forms as weld slag at the weld surface after cooling, then the uniform microstructure without crystal crack is obtained finally. In all GTA welding specimens tested, the failure is located in the heat affected zone and the tensile strength is similar to the base metal.

Thermal Transport between Graphene Sheets and SiC Substrate by Molecular-Dynamical Calculation

Using nonequilibrium molecular dynamics, we investigate the mechanisms of thermal transport across SiC/graphene sheets. In simulations, 3C-, 4H-, and 6H-SiC are considered separately. Interfacial thermal resistances between Bernal stacking graphene sheets and SiC (Si- or C-terminated) are calculated at the ranges of 100 K~700 K. The results indicate, whether Si-terminated or C-terminated interface, the interfacial thermal resistances of 4H- and 6H-SiC have similar trends over temperatures. Si-terminated interfacial thermal resistances of 3C-SiC are higher than those of 4H- and 6H-SiC in a wide temperature range from 100 K to 600 K. But, for C-rich interface, this range is reduced from 350 K to 500 K.