Study on Level Fluctuation of Twin Roll Strip Caster by Water Modeling

Ｔｗｉｎｒｏｌｌｓｔｒｉｐｃａｓｔｉｎｇｉｓｒｅｇａｒｄｅｄａｓａｐｒｏｓｐｅｃ ｔｉｖｅｔｅｃｈｎｏｌｏｇｙｏｆｎｅａｒｎｅｔｓｈａｐｅｃｏｎｔｉｎｕｏｕｓｃａｓｔｉｎｇｗｈｉｃｈｉｓｕｓｅｄｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆ 1 6ｍｍ .Ｐｒｅｓｅｎｔ ｌｙ ,ｔｈｉｓｔｅｃｈｎｏｌｏｇｙｉｓｂｅｃｏｍｉｎｇｍａｔｕｒｅｄａｎｄｃｏｍ ｍｅｒｃｉａｌｉｚｅｄ .Ｔｈｅｋｅｙｐｒｏｂｌｅｍｉｓｈｏｗｔｏｅｎｓｕｒｅｂｏｔｈｓｔｒｉｐ ｑｕａｌｉｔｙａｎｄｓｍｏｏｔｈｏｐｅｒａｔｉｏｎ .Ａｒｅａｓｏｎａｂｌ…     

FeMnAl单辊法薄带连铸工艺及其性能研究

ＦｅＭｎＡｌ单辊法薄带连铸工艺及其性能研究ＳｔｕｄｙｏｎＦｅＭｎＡｌＳｉｎｇｌｅ－ＲｏｌｌＴｈｉｎＳｔｒｉｐＣａｓｔｉｎｇＰｒｏｃｅｓｓａｎｄｔｈｅＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅＳｙｓｔｅｍ摘自冶金部钢铁研究总院研究生宋璞生的博士学位论文，...     

生产板带钢材的新流程及主要设备

生产板带钢材的新流程及主要设备徐敦乔（二重集团设计研究院；邮编：６１８０１３）Ｎｅｗｐｒｏｃｅｓｓａｎｄｍａｉｎｅｑｕｉｐｍｅｎｔｓｆｏｒｐｒｏｄｕｃｉｎｇｓｔｒｉｐ￥ＸｕＤｕｎｑｉａｏ（ＤｅｓｉｇｎａｎｄＲｅｓｅａｒｃｈｉｎｓｔｉｔｕｔｅｏｆＳＨＭ...     

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

Ｈｉｇｈ ｓｐｅｅｄｓｔｅｅｌ (ＨＳＳ) ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｘ ｃｅｌｌｅｎｔｈａｒｄｎｅｓｓ ,ｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｎｄ ｇｏｏｄｒｅｄｈａｒｄｎｅｓｓ .Ｒｅｃｅｎｔｌｙ ,ＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｈｏｔｒｏｌｌｉｎｇｒｏｌｌｓｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆｇｏｏｄｓｈａｐｅａｎｄｓｍａｌｌｃｒｏｗｎｗｉｔｈｅｘｔｅｎｄｅｄｒｏｌｌｓｅｒｖｉｃｅｌｉｆｅ[1,2 ] .ＴｈｅＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｒｏｌｌｃｏｌｌａｒｆｏｒ…     

Research on Purifying Emulsion Using Electromagnetic Technique and Its Control System

Ｅｍｕｌｓｉｏｎｉｓｕｓｕａｌｌｙｕｓｅｄａｓｌｕｂｒｉｃａｎｔｏｎ 2 0 ｒｏｌｌｅｒＳｅｎｄｚｉｍｉｒｃｏｌｄｒｏｌｌｉｎｇｍｉｌｌａｔＳｉｌｉｃｏｎＳｔｅｅｌＳｔｒｉｐＰｌａｎｔ ,ＷｕｈａｎＩｒｏｎ＆ＳｔｅｅｌＣｏ .Ｄｕｒｉｎｇｔｈｅｐｒｏｃｅｓｓｏｆｒｏｌｌｉｎｇ ,ｅｍｕｌｓｉｏｎｐｌａｙｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｃｏｏｌｉｎｇａｎｄｌｕｂｒｉ ｃａｔｉｏｎ .Ｄｕｅｔｏｈｉｇｈｐｒｅｓｓｕｒｅｂｅｔｗｅｅｎｒｏｌｌｅｒａｎｄｓｔｅｅｌｓｔｒｉｐ .Ｔｈｅｉｒｏｎｏｘｉｄｅｒｅｍａｉ…     

Catalytic Oxidative Properties and Characterization of CuO／CeO2 Catalysts

ＣｅＯ2 ｏｒｍａｔｅｒｉａｌｓｃｏｎｔａｉｎｉｎｇＣｅＯ2 ｐｏｓｓｅｓｓｕｎｉｑｕｅｒｅｄｏｘｐｒｏｐｅｒｔｉｅｓｉｎｃａｔａｌｙｔｉｃｐｒｏｃｅｓｓｅｓ[1～ 3] ,ａｎｄｃａｎｉｍｐｒｏｖｅｄｉｓｐｅｒｓｉｏｎｏｆａｃｔｉｖｅｃｏｍｐｏｎｅｎｔｓｏｎｔｈｅｓｕｐ ｐｏｒｔｓａｎｄｔｈｕｓｅｎｈａｎｃｅｔｈｅｉｒｔｈｅｒｍａｌｓｔａｂｉｌｉｔｙａｎｄｃａｔａｌｙｔｉｃａｃｔｉｖｉｔｙ .ＭｏｓｔｓｔｕｄｉｅｓｈａｖｅｕｓｅｄＣｅＯ2 ａｓａｎａｄｄｉｔｉｖｅ[4 ] ａｎｄｅｘａｍｉｎｅｄｉｔｓｉｎｔｅｒａ…     

Study on Heterogeneous Nuclei in Cast H13 Steel Modified by Rare Earth

Ｔｈｅｐｏｏｒｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｃａｓｔｍａｔｅｒｉａｌｓ ,ｅｓｐｅｃｉａｌｌｙｌｏｗｔｏｕｇｈｎｅｓｓ ,ｉｓａｍａｉｎｆａｃｔｏｒｌｉｍｉｔｉｎｇｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｐｒｅｃｉｓｅｃａｓｔｄｉｅｓ[1] .ＴｈｒｏｕｇｈｔｈｅｍｏｄｉｆｉｃａｔｉｏｎｏｆｃａｓｔＨ1 3ｓｔｅｅｌｂｙＲＥ ,ｔｈｅｄｅｎｄｒｉｔｅｓｅｇｒｅｇａｔｉｏｎｏｆＣＨ1 3ｓｔｅｅｌｗａｓｉｍｐｒｏｖｅｄａｎｄｇｒａｉｎｂｏｕｎｄａｒｙｃａｒｂｉｄｅｗａｓａｌｓｏｕｎｄｅｒｃｏｎｔｒｏｌ.Ａｃｃ…     

DSC Investigation of Phase Transitions in System LaH2-LaH3

Ｆｏｒｔｈｅｌｉｇｈｔｒａｒｅｅａｒｔｈｈｙｄｒｉｄｅｓｒｅｓｅａｒｃｈ ,ａｓａｍａｔｔｅｒｏｆｆａｃｔ,ｉｎｍｏｓｔｐｕｂｌｉｃａｔｉｏｎｓｔｈｅｓｏｌｉｄｓｏｌｕｔｉｏｎｏｆｔｈｅｒａｒｅｅａｒｔｈｄｉ ａｎｄｔｒｉｈｙ ｄｒｉｄｅｓｗｅｒｅｔｒｅａｔｅｄａｓａｃｏｍｐｌｅｔｅｌｙｈｏｍｏｇｅ ｎｅｏｕｓ .ＥｖｉｄｅｎｃｅｓｉｎｄｉｃａｔｉｎｇｔｈｅｅｘｉｓｔｅｎｃｅｏｆｄｉｆｆｅｒｅｎｔｐｈａｓｅｓｉｎｔｈｅＬａＨ2 ＬａＨ3 ｓｙｓｔｅｍｃａｍｅｆｒｏｍＸ ｒａｙｓｔｕｄｉｅｓａｎｄｎｅｕｔｒｏ…     

Investigation of the Service Properties of the Electroslag Cast Metal

Ｉｎａｌｔｒａｄｉｔｉｏｎａｌｍｅｔｈｏｄｓｏｆｓｈａｐｅｄｃａｓｔｉｎｇ，ｍｅｔａｌｉｓｐｒｅｐａｒｅｄｉｎａｍｅｌｔｉｎｇｆｕｒｎａｃｅａｎｄｔｈｅｎｐｏｕｒｅｄｉｎｔｏａｍｏｌｄ．Ｓｅｃｏｎｄａｒｙｏｘｉｄａｔｉｏｎｏｃｃｕｒｓｂｅ－ｃａｕｓｅ...     

Contents and Distribution of Rare Earth Elements in Main Types of Soils in China

Ｓｔｕｄｙｏｎｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓ（ＲＥＥ）ｃｏｎｔｅｎｔｓｉｎｔｈｅｍａｉｎｔｙｐｅｓｏｆｓｏｉｌｓｉｎＣｈｉｎａｉｓｏｆｓｉｇｎｉｆｉｃａｎｃｅｆｏｒｆｕｒｔｈｅｒｅｘｐｏｕｎｄｉｎｇｔｈｅｃｈｅｍｉｃａｌｂｅｈａｖｉｏｒｓｓｕｃｈａｓｍｏｂｉｌｉｔｙ,ａｃｃｕｍｕｌａｔｉｏｎｏｆｔｈｅＲＥＥｉｎｔｈｅｓｏｉｌｆｏｒｍｉｎｇｐｒｏｃｅｓｓｅｓ．Ｏｎｔｈｅｏｔｈｅｒｈａｎｄ,ａｓＲＥＥａｖａｉｌａｂｉｌｉｔｙｖａｒｉｅｓｗｉｔｈｓｏｉｌｃｏｎｄｉｔｉｏｎｓ,ｉｔｉｓｎｏｔｕ…     

Material Characterization of Austempered Ductile Iron (ADI) Produced by a Sustainable Continuous Casting–Heat Treatment Process

Selecting a suitable manufacturing process is one way of achieving sustainability of a product by diminishing energy consumption during its production cycle and improving material efficiency. The article attempts to explore the new processing technology for direct manufacturing of lightweight austempered ductile iron (ADI) casting in a permanent mold. The new processing technology is based on the innovative integrated approach toward casting and heat-treatment process. In this technology, the ductile iron samples obtained using the permanent mold are first austenized immediately after solidification process followed by austempering heat treatment in the fluidized bed and then air cooled at room temperature to obtain ADI material. The influence of austempering time on the microstructural characteristics, mechanical properties, and strain-hardening behavior of ADI was studied. Optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses were performed to correlate the mechanical properties with microstructural characteristics. It was observed that the mechanical properties of resulting ADI samples were influenced by the microstructural transformations and varied retained austenite volume fractions obtained due to different austempering time. The results indicate that the strain-hardening behavior of the ADI material is influenced by the carbon content of retained austenite.     

Analysis of bulging for high speed continuous casting

In order to research the temperature distribution and mechanical deformation of slab bulging during high speed continuous casting,mathematical models have been developed to analyze the thermal and mechanical behavior of the slab.The thermal history of the slab has been predicted by a two-dimensional transient finite element heat transfer model,whose results serve as the input to the stress model.The stress model has been formulated for a two-dimensional longitudinal plane.In this case,the maximum tensile strain during the bulging process is located at the solidification front just past the top of the upstream roll,which may contribute to crack formation.The maximum tensile stresses are located at the cold surface in the middle of the two back-up rolls,just at the point of the maximum bulging.Stresses near the solidification front are small because of the high temperatures which produce lower elastic modulus values.Finally,the effect of the casting speed on the bulging deformation is discussed.     

电磁搅拌下连铸圆坯凝固传热及应力的数值模拟

 针对电磁搅拌作用下碳钢在连铸结晶器内的凝固过程,考虑铸坯和结晶器内的接触状态,建立了完全热力耦合的三维稳态有限元模型。结果显示,电磁搅拌加快了钢液热量的释放,使气隙生长延迟,与无外加磁场的情况相比,坯壳内的等效米塞斯应力加大,凝固前沿附近超过了材料能承受的抗拉强度,且处于脆性温度范围区间,可能诱发裂纹形成。     

As-Cast Residual Stresses in an Aluminum Alloy AA6063 Billet: Neutron Diffraction Measurements and Finite Element Modeling

The presence of thermally induced residual stresses, created during the industrial direct chill (DC) casting process of aluminum alloys, can cause both significant safety concerns and the formation of defects during downstream processing. Although numerical models have been previously developed to compute these residual stresses, most of the computations have been validated only against measured surface distortions. Recently, the variation in residual elastic strains in the steady-state regime of casting has been measured as a function of radial position using neutron diffraction (ND) in an AA6063 grain-refined cylindrical billet. In the present study, these measurements are used to show that a well-designed thermomechanical finite element (FE) process model can reproduce relatively well the experimental results. A sensitivity analysis is then carried out to determine the relative effect of the various mechanical parameters when computing the as-cast residual stresses in a cylindrical billet. Two model parameters have been investigated: the temperature when the alloy starts to thermally contract and the plasticity behavior. It is shown that the mechanical properties at low temperatures have a much larger influence on the residual stresses than those at high temperatures.     

基于凝固传热模型的轴承钢GCr15二冷研究与应用

采用Gleeble 3500热应力/应变模拟机对轴承钢GCr15进行了高温力学性能测定，根据实际测量的结果，优化原有二冷制度并提出了适合轴承钢二冷冶金准则的二冷水表。并根据实际情况建立了大方坯连铸凝固传热模型，通过射钉试验表明模型准确可靠，在此基础之上提出了基于凝固传热模型的动态二冷控制方法，通过生产实践表明采用特征拉速控制二冷配水可以有效改善铸坯质量。     

基于无网格伽辽金法的连铸坯凝固计算方法

为考察无网格方法求解铸坯凝固过程的可行性,本文依据移动最小二乘和变分原理,推导并建立了基于无网格伽辽金法的结晶器内铸坯凝固过程二维非稳态传热/凝固数学模型。以小方坯凝固过程为对象,分别采用节点均匀布置、加密布置、随机布置方式,模拟分析了小方坯凝固过程的温度场变化,并将计算结果与参考解、有限元法数值解进行了对比,结果证实无网格伽辽金法在计算精度、自适应性、网格依赖性等方面均优于有限元法。研究结果为无网格方法应用于连铸过程的传热、凝固以及应力/应变行为的数值计算提供参考。      

The GA Optimization Performance in the Microstructure and Mechanical Properties of MMNCs

This paper is aimed at development of an effective approach based on the combination of GA, FEM and artificial intelligent methods to determine the optimum conditions of Al Matrix nano composites in terms of microstructure and mechanical properties. Using the stir casting method, alumina nano-particles were incorporated into the Al–Si aluminum alloy. Characterization of the mechanical properties showed that the presence of nano particles significantly improved the hardness and strength of the composites. Then artificial neural network and finite element technique were implemented in order to predict the mechanical properties and genetic algorithms were used for the process conditions optimization. It was revealed that the proposed model is a useful and efficient method to find the optimal process conditions in stir casting.     

结晶器内连铸坯的热和应力状态数值模拟

针对碳钢在连铸结晶器内的凝固过程，考虑铸坯和结晶器内的接触状态，利用ANSYS软件建立了完全热力耦合的三维稳态有限元模型，模拟出结晶器区域内的热和力学状态，包括铸坯应力场、气隙分布规律以及整个结晶器内钢液温度分布等。结果显示，铸坯出结晶器时坯壳外层处于压缩状态、内层处于拉伸状态，内外表面应力分别为279、311 MPa，凝固前沿处应力为3 MPa左右，处于材料的极限强度范围，有产生裂纹的可能。锥度结晶器有利于钢液凝固换热，采用0.7%/m的倒锥度设计后，气隙量较无锥度结晶器最多减少了42%。     

Microsegregation behavior during solidification and homogenization of AerMet100 steel

Cast AerMet100 exhibits mechanical properties comparable to the wrought properties of competing ultrahigh-strength steels; however, the segregation behavior had not been quantified under casting conditions. A microsegregation profile of the as-cast ingot was simulated and homogenization treatments were predicted using Thermo-Calc and DICTRA software. Experimental composition analysis confirmed the simulated microsegregation profile, and the homogenization process occurred at a slightly faster rate than predicted. The convergence of theory and experiment demonstrates the feasibility of designing cast alloy compositions assisted by computer simulation to minimize segregation without casting a large experimental matrix of test ingots.     

连铸与模铸高铁车轴钢的高周疲劳破坏行为

连铸车轴钢能否达到模铸车轴钢的性能水平是其能否应用的一个关键。对此,采用旋转弯曲疲劳试验及疲劳裂纹扩展速率试验对比研究了连铸与模铸工艺生产的高铁车轴钢的高周疲劳破坏行为。结果表明,工业试制的连铸车轴钢的强度和疲劳极限均低于模铸车轴钢,且前者的疲劳裂纹扩展速率略高于后者。疲劳断口分析表明,疲劳断裂大部分起源于试样表面基体。微观组织分析表明,尽管两者的微观组织均为高温回火马氏体,但连铸车轴钢中原奥氏体晶粒尺寸及碳化物均略大于模铸车轴钢。金相评级法及夹杂物极值统计法的结果均表明,连铸车轴钢中的夹杂物尺寸明显大于模铸车轴钢。因此,为了以连铸工艺取代模铸工艺,还需要进一步优化连铸车轴钢的成分、冶金生产和热处理等工艺,以获得优良的冶金质量和组织性能。