| Currently roller sleeve of twin-roll continuous casting process used to produce aluminum slab is mainly steel roller sleeve. Due to the low thermal conductivity of steel affects melt solidification rate thereby affecting the casting speed and product quality. So increasing casting speed must increase the melt solidification rate, effective way to develop this is to use a high thermal conductivity roll sleeve material. In all copper alloy beryllium copper alloy has high strength hardness, high electrical and thermal conductivity, high creep strength, wear and corrosion resistance, non-magnetic and shock does not produce sparks and other comprehensive performance, especially low high conductivity beryllium copper beryllium alloys of beryllium content of 0.2-0.6wt.% is the most potential material to achieve roller cover with copper and steel material, it can improve efficiency and quality of the aluminum slab continuous casting process. The current study of beryllium copper alloys abroad are mainly concentrated in the high-strength beryllium copper(beryllium content 0.2-0.6wt.%) of beryllium content in 1.6-2.0wt.%, for research and application of low beryllium copper alloy of certain service conditions with high thermal / electrical properties has been reported rarely.In this paper, Cu-0.23Be-0.84 Co is as the research object, the thermodynamic properties and the preparation process of Cu-0.23Be-0.84 Co has been studied; Cu-0.23Be-0.84 Co alloy hot compression deformation was done on Gleeble-1500 thermal simulation testing machine to be studied the thermal deformation rheological behavior of alloy, analyzed different deformation conditions on alloy flow stress, calculated the thermal deformation activation energy of the alloy, and the beryllium copper alloy deformation constitutive equations was been established hot deformation constitutive equation of Cu-0.23Be-0.84 Co alloy. Cu-0.23Be-0.84 Co alloy processing map was been built according to the theory of dynamic material model, revealed the variation of the microstructure during the thermal deformation of the alloy, obtained optimal thermal process parameters of Cu-0.23Be-0.84 Co alloy. To provide theoretical guidance for the actual thermal processing of alloys; According to DEFORM-3D finite element software, and combined with the material propertie parameters of paper developed Cu-0.23Be-0.84 Co alloy, distribution of Cu-0.23Be-0.84 Co alloy roll sleeve temperature field and stress were analyzed mostly for casting speed and other parameters influence, and compared with the most commonly used steel roller sets.The results showed that: The influence of temperature variation of the thermal conductivity on Cu-0.23Be-0.84 Co alloy is low, its average thermal conductivity is 239 W/m?k, is about ten times of the steel; In the hot deformation process,thermal alloy Cu-0.23Be-0.84 Co activation energy is 419.480 k J/mol, the flow stress model during thermal deformation: 65.49 22.25??=e[sinh(0.0041?)] exp(?419480 / 8.31T). the thermal processing graph of Cu-0.23Be-0.84 Co alloy shows that: when the amount of deformation of 0.1 to 0.3, alloy security zone is large during hot compression, mainly in the high-temperature and high strain rate zone strain rate zone; When the deformation of 0.4 to 0.6, alloy exist a security zone, the zone of deformation temperature of 450~725℃, strain rate of 0.7~10s-1 during hot compression deformation; Cu-0.23Be-0.84 Co alloy roller sets numerical simulation results show that: the heat of roller sleeve contacting zone mainly concentrated in the vicinity of the surface layer, the closer to the surface layer, the higher of the temperature, but the inside of the roller temperature changes small; Temperature of copper casting roll sleeve in the region is higher and higher with the temperature rises, but the maximum temperature change range smaller, When the casting temperature rises from 650℃ to 700℃, in Casting Zone, the maximum temperature of roller sets varies from 328℃ to 365℃, which maximum temperature of roller sleeve is 364℃ at 680℃. When the casting speed is from 0.8m/min to 2m/min, the maximum temperature difference inside and outside surfaces of the roller sleeve increased from 257℃ to 265℃. So increasing casting speed of the roller sleeve less affected by the temperature difference between inside and outside; In the casting speed of 2m/m and casting temperature of 680℃ conditions, copper roller sleeve of thermal conductivity of 239W/m?k which the maximum temperature of the surface is 245℃, and steel roller sleeve of thermal conductivity of 25W/m?k, which surface temperature is 305℃, therefore, surface temperature distribution of roll Shell greatly influenced by thermal conductivity. In the casting process, the compressive stress of Cu-0.23Be-0.84 Co alloy roll sleeve is mainly in the outer layer casting roll sleeve. |
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