快速超薄铸轧机铸轧辊变形测量系统研究

针对铸轧工艺的特殊性,拟定了一套方便可行的铸轧辊变形测试方案.运用该方案对某铸轧机成功地进行了工业现场测试,掌握了铸轧辊在铸轧环境下变形的分布规律,测试实际铸轧过程中轧辊受力载荷与温度场作用下辊形变化规律、测试设备运行时的有关工艺参数与力能参数,以及设备参数,同时也为仿真模型提供边界条件及检证标准.     

超薄快速铸轧机铸轧辊温度场和热凸度仿真及实验

轧辊热凸度是影响板形的一个重要因素,其计算精度直接影响到成品的板凸度和板形精度。采用轴对称差分法计算了超薄快速铸轧机铸轧辊温度场和热凸度,计算结果与现场测试结果相吻合,为铸轧辊原始设计和板形控制提供了依据。     

铸轧机轧辊使用寿命的探讨

从亨特铸轧机的辊套与辊芯的装配和铸轧工艺两方面分析了影响铸轧辊使用寿命的因素,并提出改进措施,提高了轧辊使用寿命。     

铸轧辊变形在线测量研究

针对铸轧工艺的特殊性，拟定了一套方便可行的铸轧辊变形测试方案。运用该方案对某铸轧机成功地进行了工业现场测试，掌握了铸轧辊在铸轧环境下变形的分布规律，测试实际铸轧过程中轧辊在力载荷与温度场作用下辊形变化规律、测试设备运行时的有关工艺参数与力能参数，以及设备参数，同时也为仿真模型提供边界条件及检证标准。     

挤压铸造铸件凝固过程热力耦合分析

用热力耦合方法分析了锌铝合金挤压铸造凝固过程中的温度场以及由此产生的应力、应变场.对传热系统模型中的对流、辐射边界条件和凝固潜热进行了处理.建立了热粘弹塑性有限元模型,用有限元软件进行数值计算分析,并给出了计算结果.     

铝带坯铸轧机铸轧辊套材料及热处理

叙述了铝带坯铸机用铸轧辊套要求的机械性能和物理性能;讨论了化学成分,热处理工艺对铸轧辊套性能的影响;即对辊套使用寿命的影响;说明了材料组织为细小的回火索氏体是最佳组织。     

铸轧辊温度场及热变形测定

针对铸轧工艺的特殊性，拟定了一套方便可行的铸轧辊温度场及热变形测试方案，运用该方案对某铸轧机成功地进行了工业现场测试，掌握了铸思辊在铸轧环境下温度场及热变形的分布规律，为铸轧板形控制及现场铸轧工艺优化提供了可靠依据。     

斜轧机轧辊辊形的计算

根据斜轧特点,利用坐标变换和变量代换方法,导出了两种计算任何斜轧辊形的公式。     

汇气管热模拔成形热力耦合分析

采用弹塑性大变形热力耦合有限元法理论,应用有限元仿真软件ABAQUS,建立了汇气管热模拔有限元模型,研究了直径Φ508 mm、壁厚18 mm汇气管热模拔成形工艺过程。重点分析了不同温度场下热模拔成形过程中汇气管的应力应变及形变位移,得到了热模拔成形工艺最佳的温度场。研究分析表明:对于低碳钢汇气管,一般热拔制成形的最佳温度场控制在1000℃左右;拔制过程中,加热拔制区域的材料的塑性变形符合材料塑性行为的三个特征:初始屈、塑性应变增长和塑性强化;拔制成形后,管件的最大残余应力出现在拔制椭圆孔短轴附近,但都满足低碳钢的失效强度。最后,对比有限元模拟结果与实验结果获得了很好的一致性,验证了模拟的可行性。     

穿孔过程中顶头的三维热力耦合分析

应用大型非线性有限元分析软件对顶头在实心圆管坯二辊斜轧穿孔过程中的受力状态进行了三维热力耦合模拟。重点研究了热力耦合情况下表面应力分布模型,同时也对顶头的失效机理、材料模型、传热边界条件等进行了分析。模拟结果和实验结果相吻合。     

Development and application of coupling model of aluminum thin-gauge high-speed casting

Based on the analyses of aluminum melt flow, solidification, heat transfer during the process of twin-roll casting, a coupling mathematical model of aluminum thin-gauge high-speed casting was developed, which included the casting roller shell. At the same time, Galerkin method was adopted to solve the coupling model. The fluid field and temperature field of aluminum melt in casting zone, the temperature field and thermal stress field of roller shells were simulated by the coupling model. When the casting velocity is 7 m/min, and the thickness of strip is 2 mm, the circumfluent area comes into being in the casting zone, and the mushy zone dominates the casting zone, while the temperature of melt decreases rapidly as it approaches the rollers. The temperature of the roller shell varies periodically with the rotation of roller, and reaches the highest temperature in the casting zone, while the temperature of roller shell decreases gradually as it leaves the casting zone. The difference of thermal stress between the inner surface and outer surface of the roller shell is very large, and the outer surface suffers tensile-compressive stress.     

Turbulence flow and heat transfer of aluminum melt in tip cavity in process of thin-gauge high-speed casting

The uniformity of flow distribution of aluminum melt in tip cavity is a precondition to decide whether or not thin-gauge high-speed casting can be accomplished smoothly. The laws of aluminum melt flow and heat transfer in tip cavity can be found out through numerical simulation, which gives theoretical basis for solving the problem of the flow distribution of melt in tip cavity. A mathematical model with a low Reynolds number k--ε model for turbulence flow and heat transfer of aluminum melt in tip cavity was developed. The finite difference method was used to calculate the flow field and temperature field of aluminum melt in tip cavity. The phenomena and characteristics of turbulence flow and heat transfer were analyzed, including the characteristics of temperature distribution of turbulence similar to that of laminar flow. The simulation results are in good agreement with the experimental results for flow velocities and temperature at the exit of tip, which verifies the validity of the simulation results.     

铝合金的超常铸轧制备

铝合金连续铸轧以其短流程、高效、节能等突出的优势成为铝板带热轧坯的主要生产模式之一,特别是在我国其产量已大于热轧板.因此,提高其产品质量和生产效率成为十分突出的普遍问题.提出"超常铸轧"技术思路,通过强化铸轧环境,改变铸轧工艺,使铝合金铸轧组织发生新的演变,板材性能全面改善,成型性有显著提高."超常铸轧"的核心技术是:1)基于高能量密度输运的热传导技术;2)基于外加瞬时随机变化磁场的铸轧区熔体强微扰动技术.研究了两种新技术的科学原理和技术要素.     

镁合金薄板快速铸轧过程有限元仿真研究

为了研究铸轧工艺参数对AZ31镁合金薄板快速铸轧过程温度场和热应力场的影响,基于铸轧区板坯的对称性建立了纵截面1/2的二维几何模型;选择了基于热弹塑性增量理论的热应力控制方程;采用大型通用有限元分析软件ANSYS对镁合金快速铸轧过程中的铸坯温度场和热-应力场进行了仿真分析,并就不同工艺参数(浇注温度、接触界面换热系数、铸轧速度)对铸坯温度和应力的分布及其相变区的影响进行了研究。仿真结果增强了对镁合金快速铸轧过程相变区温度变化和热裂产生机制的理解,为快速铸轧工艺参数的优化提供了依据。     

铸轧板形的影响因素及控制策略

本文阐述了铸轧板形的力学本质 ,并推导出板形的计量公式。结合大量试验观察 ,基于“广义原始辊缝”概念 ,运用体积不变原理及 P-H图对铸轧环境下板形的影响因素进行了分析 ,提出铸轧板形主要与金属的布流状态有关 ,针对板形缺陷的不同模式提出了相应控制策略。     

铸轧辊辊套断面温度场的数值模拟

本文介绍了用有限差分法求解铸轧辊辊套中的周期性动边界下的瞬态温度场,采用该方法实现了铸轧辊辊套从铸轧开始到达到热平衡时的整个铸轧过程中的温度场数值模拟,结果令人满意。     

Comparison of phosphor bronze metal sheet produced by twin roll casting and horizontal continuous casting

Much effort recently has been expended to study the strip casting process used to produce thin metal strip with a near final thickness. This process eliminates the need for hot rolling, consumes less energy, and offers a feasible method of producing various hard-to-shape alloys. The finer microstructure that results from the high cooling rate used during the casting process enhances mechanical properties. In this study, strips of phosphor bronzes (Cu-Sn-P) metal were produced using a twin roll strip casting process as well as a conventional horizontal continuous casting (HCC) process. The microstructures, macrosegregations, textures, and mechanical properties of the as-cast and as-rolled metal sheet produced by these two methods were examined carefully for comparative purposes. The results indicate that cast strip produced by a twin roll caster exhibit significantly less inverse segregation of tin compared to that produced by the HCC process. The mechanical properties including tensile strength, elongation, and microhardness of the products produced by the twin roll strip casting process are comparable to those of the HCC processed sheet. These properties meet specifications JIS H3110 and ASTM B 103M for commercial phosphor bronze sheet. The texture of the as-rolled sheet from these two processes, as measured from XRD pole figures, were found to be virtually the same, even though a significant difference exists between them in the as-cast condition.     

Production of 150 cm wide AZ31 magnesium sheet by twin roll casting

150 cm wide AZ31 magnesium alloy sheet was produced by twin roll casting. The sheets of 6 mm thickness were cast.The sheet material was characterized using various techniques including metallography and XRD. The mechanical properties were investigated by tensile tests and hardness measurements. The procedures were developed for thermomechanical treatment of cast sheet material. The products of these procedures were characterized and the results were discussed for possible potential applications.     

连铸小方坯在步进冷床上的温降计算

探讨了小方坯在步进冷床下线的温降过程。理论推导了小方坯辐射散热的计算公式,并利用有限元软件对连铸小方坯冷却模型进行了数值模拟,对比分析了不同条件对铸坯温降的影响,结果表明铸坯温降过程主要由热辐射散热决定。通过考虑不同影响因素及实际生产条件的差异,得出了小方坯在步进冷床下线的温降时间估算公式,用于指导相关工程设计。     

连铸板坯辊式电磁搅拌多场耦合模拟

基于库伦规范的Maxwell方程组与标准[k-ε]湍流模型,在考虑铸机结构与铸坯凝固的条件下建立了电磁搅拌传输数值计算的模型。研究了连铸板坯二冷区辊式电磁搅拌凝固坯壳形状与钢液流场的相互影响。结果表明：相对于不考虑凝固,凝固坯壳明显减弱了电磁搅拌强度;凝固坯壳使得钢液流速降低,回流区影响范围减小。电磁搅拌作用下的流场与传热影响凝固坯壳的形状。