共查询到19条相似文献,搜索用时 140 毫秒
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在经典轧制理论和现代连铸理论相结合的基础上,推导出了铸轧力计算公式,并建立了一个非线性状态空间模型,描述双辊结晶器内的金属凝固和塑性变形,此模型可以作为双辊铸轧薄带钢过程铸轧力的实时在线控制模型。 相似文献
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针对双辊铸轧过程中凝固终点位置这一关键参数,基于贝叶斯方法的神经网络和理论模型,根据经验模型及熔池断面几何关系建立凝固终点位置数学模型.在化学成分和工艺约束已知的条件下,采用粒子群优化算法针对凝固终点位置这一铸轧过程中的关键因素进行相应的工艺参数的优化计算.铸轧实验结果验证了优化结果的可行性,从而为提高双辊铸轧板形和板厚的控制精度,改善铸带表面质量提供可能. 相似文献
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利用铝双辊铸轧过程传热数学模型,系统分析了辊套材料、浇注温度等工艺因素对铝双辊铸轧过程凝固速率的影响及进一步提高铸轧机生产能力的途径,建立了钢和铜合金2种辊套材料的凝固壳厚度随时间变化的计算公式。 相似文献
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特种合金双辊薄带连铸生产技术进展 总被引:1,自引:0,他引:1
双辊薄带连铸技术(TRC)已发展到产业化的初级阶段,如日本新日铁、德国Eurostrip、美国Castrip、韩国Postrip等公司的薄带连铸生产能力已达30~50万t/a,多炉连浇时间超过10h。介绍了多种特种合金,如髙硅电工钢(w(Si)为4.5%~6.5%)、高速钢、Invar合金、Inconel合金、TWIP钢等可用双辊薄带连铸,一次性形成毫米级薄带。由于高速冷凝,晶粒细化,成分偏析极少,生产成本低,成材率高,TRC是当前双辊薄带连铸产业化的新途径之一。 相似文献
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ZHOU Guo-ping LIU Zhen-yu YU Shi-chuan CHEN Jun QIU Yi-qing WANG Guo-dong 《钢铁研究学报(英文版)》2011,18(2):18-23
The formation of phosphorous surface inverse segregation (SIS) in twin-roll cast strips of low-carbon steels was studied. High phosphorous strips were fabricated by using a pilot twin-roll strip caster and a melt/substrate contacting apparatus, respectively. Solidification structures of strips were observed and analyzed, and phosphorus distributions along longitudinal sections of strips were investigated and discussed. The results showed that solidification structures of all strips were columnar grains, either integrated or coarse in the strip made by the melt/substrate contacting apparatus or damaged in some degree in cast strips; and that during cast strip solidification, enrichment of phosphorus occurred between columnar grains, and the average phosphorus concentration near the surface in the strip with 015% of phosphorus was measured to be about 027% which was obviously higher than that in the bulk. 相似文献
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Zhiyu Liu Bo Wang Qinghua Zhang Jie Ma Jieyu Zhang 《Metallurgical and Materials Transactions B》2014,45(1):262-271
The modeling and controlling of flow and solidification of melt metal in the filling process is important for obtaining the optimal pool level and the formation of the solidified metal layer on the surface of twin-rolls during the twin-roll strip casting. The proper delivery system and processing parameters plays a key role to control flow characteristics in the initial filling stage of the twin-roll strip casting process. In this paper, a commercial CFD software was employed to simulate the transient fluid flow, heat transfer, and solidifications behaviors during the pouring stage of twin-roll strip casting process using different delivery systems. A 3D model was set up to solve the coupled set of governing differential equations for mass, momentum, and energy balance. The transient free-surface problem was treated with the volume of fluid approach, a k–? turbulence model was employed to handle the turbulence effect and an enthalpy method was used to predict phase change during solidification. The predicted results showed that a wedge-shaped delivery system might have a beneficial impact on the distribution of molten steel and solidification. The predicted surface profile agreed well with the measured values in water model. 相似文献
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In this study,morphological and microstructural analyses were conducted on net-shaped microcracks appearing on the surface of low-carbon steel manufactured via twin-roll strip casting. The fractograph and microscale distribution of elements in the cracked region were also analyzed. Results revealed that the cracked surfaces were characterized by slight pits,along with inclusions composed of manganese and silicon oxide distributed along both the sides of the cracks. Fractograph analysis revealed that the crack and smooth dendrite surfaces were oxidized. These phenomena indicate that microcracks on the cast strip surface form at the hightemperature stage of the solidification process during twin-roll casting and rolling. Microcracks were present in each region with pits in the cast strip and extended along the dendrite interface because of the combined effects of phasechange stress,thermal stress,mechanical stress,and fractional crystallization during the solidification process. 相似文献
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The development of continuous casting technology of electrical steel was analyzed. The technologies and products characteristics of conventional continuous casting, thin slab continuous casting and rolling, middle thin slab continuous casting and rolling and twin-roll thin strip were compared. Conventional continuous casting technology was widely adopted in producing electrical steel; thin slab continuous casting and rolling and middle thin slab continuous casting and rolling technology industrialized electrical steel; and study of twin-roll thin strip casting technology was focused on fundamental experiments. 相似文献
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The influence of process parameters on the dendritic microstructure of thin strips cast by the twin-roll method is analyzed in the framework of a one-dimensional solidification model and compared with experimental results. As a relevant characteristic the secondary dendrite arm spacing Λ2 as a function of the distance x from the roll surface is investigated. The difference between the local dendrite arm spacing near the strip surface and the strip centre, respectively, increases with the strip thickness and only depends on the casting temperature to a small extent. An increase in the strip/roller heat transfer coefficient due to a rising casting velocity or possibly enhanced roll-separating forces leads to a decrease in the dendrite arm spacing. The effect of a sudden decrease in heat transfer during the solidification process, on the Λ2(x) characteristics, e.g. by a local separation of the solidified shell from the roller surface, is discussed. 相似文献
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The microstructures of strip-cast low-carbon steels and their response to thermal processing 总被引:2,自引:0,他引:2
The as-cast microstructure and its modification when subjected to heat treatment is examined for strip-cast low carbon steels. The local solidification rate in the twin-roll strip casting process is estimated to. be 590 to 850 °C/s, and the primary and secondary dendrite arm spacings are approximately 17 to 25 and 10 μm, respectively. The as-cast structure is predominantly Widmanstätten ferrite and, thereby, differs from the conventional hot-rolled sheet. It is suggested that the as-cast morphology is a result of the large initial austenite grain size and the cooling rate and is not a unique characteristic of rapid solidification of strip casting. By restricting the austenite grain size and cooling rate, polygonal ferrite morphology probably can be produced during strip casting. The response to heat treatment depends on the presence of aluminum; with a moderate amount of aluminum, the A1N precipitates in the as-cast structure inhibit the subsequent grain boundary movement and may affect the subsequent recrystallization behavior. 相似文献