基于改进粒子群算法的轧制负荷分配优化

应用改进粒子群算法,实现单机架可逆冷轧机轧制负荷分配优化。结合某厂单机架可逆冷轧机实际工况,建立了合适的轧制力数学模型并进行参数计算,以压下率为自变量,以轧制力成比例分配为目标,通过改进粒子群算法,得到最佳的轧制负荷分配。工程实践证明:与基本粒子群算法、遗传算法相比,改进粒子群算法具有计算精度更高、收敛速度更快、搜索能力更强等优点,是一种适于单机架可逆冷轧机轧制负荷分配优化的新方法。     

一种基于改进FFT的轧辊偏心分析及补偿方法

针对板带材生产过程中的轧辊偏心问题,提出基于粒子群算法的优化方法对轧制力波动信号进行频谱分析,优化采样过程中采样持续时间,实现整周期采样,克服直接使用快速傅里叶变换进行分析时易出现栅栏效应和频谱泄漏的局限性。仿真验证了方法的可行性。采集某厂650六辊可逆冷轧机的轧制力数据,为得到与优化的采样持续时间相对应的采样点,提出一种基于插值算法的数值估算方法,利用所提方法对轧制力波动进行分析,提取偏心信号并对其进行补偿,证明方法具有实用性。     

等功率裕量法在双机架可逆轧机中的应用

针对济钢双机架可逆冷轧机负荷分配不合理,采用等功率裕量法,并考虑轧制力、转矩和速度等约束条件,对负荷分配进行了优化,提高了生产效率和主电机利用率。     

国产首台宽幅十二辊冷轧机通过鉴定

由北京泰隆自动化设备有限公司研制的国产 14 0 0mm多辊可逆冷轧机已通过江苏省科技厅组织的科学技术成果鉴定。这是国内辊面最宽并已投入工业运行的十二辊单机可逆冷轧机。专家认为 ,该轧机设计合理、正确 ,其可将轧制力作用于辊身长度边缘及外侧 ,使轧辊在轧制过程中产生较小挠度 ,形成闭口孔型 ,保证稳定轧制 ;并通过其具有自主知识产权的专利“直接作用式多辊轧机板形控制装置” ,使下工作辊产生一定的向上弯曲以控制辊缝形状 ,从而控制带钢的板形。该 14 0 0mm十二辊宽带钢可逆冷轧机 ,是一套全液压轧机 ,由于采用了整体机架、上下分开…     

本溪钢铁公司订购2架冷轧机

本溪钢铁公司与德国西马克-德马格设备公司签署订单，要求后者为其提供2架六辊可逆式冷轧机。该冷轧机将用于生产碳钢薄板，最高轧制速度达1200m／min，可生产宽750-1300mm、厚0．18-1．60mm的冷轧薄板，每架冷轧机的年产量可达25万t。西马克-德马格公司所供应的六辊冷轧机配备平直度测量仪，并采用连续町变凸度控制技术，除此之外，该公司还提供所有电气设备和自动化系统，包括用于提高生产效率的新型设定模型以及满足严格质量要求的技术控制包。其中一架冷轧机最早将于2007年10月投产运行。     

热轧带钢轧制节奏的优化

针对热连轧窄带钢生产中由于精轧区轧区长度长、传统控制方式导致轧制节奏慢的问题,通过对两级自动化控制系统进行优化,设置双存储区,优化轧制规程发送时序和速度算法,解决了两块钢同时轧制的问题。唐山国丰钢铁有限公司620mm热连轧生产线据此改进后,小时产量由原先的55块提高到了72块,大大缩短了生产周期,提高了产能。     

采用CVC6辊不可逆式冷轧机生产优质铝材的新技术概念

新设计冷轧机追求的目标是增加产品产量和改进质量，以满足市场日益严格的要求，而新技术的概念在于保证高生产率和高经济效益。新的轧机概念在本质上对轧机本身，驱动系统，装备技术以及控制技术等进行了新的探索。基于程序化，过程自动化，高度自动化才能使轧制具有高操作可靠性和高轧制生产能力。     

单机架可逆式冷轧机速度制度的研究

单机架可逆冷轧机轧制速度的制定大多依据工程技术人员的经验,这种方法在实际中虽然可行,但往往不能达到最优.本文以各道次等功率分配为原则,研究了轧制速度的分配方法,并编制了相应的计算机软件,为单机架可逆式冷轧机快速制定合理的轧制速度、提高带钢产量、降低轧制能耗提供了有力的参考依据.     

单机架可逆冷轧机轧制规程优化设计

以唐钢冷轧薄板厂1 800 mm单机架可逆冷轧机的2级轧制规程为研究对象,在分析轧制负荷分配对冷轧带钢板形精度影响的基础上,系统研究了冷轧轧制模型,应用最优化方法编制了轧制规程设计程序并付诸工程实践。     

改善可逆式冷轧机性能的两条新措施

可逆式冷轧机存在有许多缺点,例如,由于无法轧制带钢头尾部分而使成材率下降,由于拆卸带卷、穿带和使用张力辊来保持带钢造成时间延误而降低了生产率。为了提高可逆冷轧机的成材率和生产率,日本SteelPlantech株式会社开发出两种新的轧制方法,Zoom—Mill法和SPEOS技术。     

Hot Compression Mechanical Behavior of Solution Heat-Treated and Pre-aged Mg-Zn-Gd-Er Alloys

The mechanical behavior of solution heat-treated and pre-aged Mg-6Zn-1Gd-1Er alloys during hot compression (from 180 to 330 °C) has been investigated. The results showed that the flow stress curves of the pre-aged sample (PAS) intersected with that of the solution heat-treated sample (SHTS) during hot compression. At 180 °C, when the true strain is 0.27 and 0.47, the PAS showed larger and smaller stress (210.80 MPa vs. 207.58 MPa and 205.67 MPa vs. 207.93 MPa) than the SHTS, respectively. These phenomena were due to the stronger interaction of W phase and dislocations/twins under the strain of 0.27, while dynamic recrystallization softening occurred under the strain of 0.47. When the temperature increased to 330 °C, the flow stress of PAS and SHTS showed an opposite trend to that of 180 °C. Continuous dynamic recrystallization and particle stimulated nucleation based on slip operations are the main deformation mechanisms under 330 °C. At the true strain is 0.33 and 0.53, the PAS has smaller and larger stress (61.32 MPa vs. 63.69 MPa and 58.75 MPa vs. 57.09 MPa) than the SHTS, respectively. The increasing deformation resistance of dynamic precipitation improved the flow stress under smaller strain and dynamic recrystallization decreased the flow stress under high strain, which resulted the opposite phenomena of SHTS.     

Photoacoustic study on cathodic reduction of anodic oxide films formed on copper in borate solution

An in-situ photoacoustic (PAS) technique, using a piezoelectric detector with high sensitivity was applied to the study on duplex oxide films anodically formed on copper in pH 8.4 borate solution. The PAS signals from the copper electrode were produced by an irradiation of light beam with a wavelength of 514.5 nm. The PAS amplitude during cathodic reduction of the outer oxide layer to Cu₂O changed in the opposite direction, depending on the anodic potential of film formation and oxidation time. Assuming that the change in PAS amplitude is proportional to both optical absorption coefficient and film thickness, it was deduced from comparison of the estimated absorption coefficients for Cu (OH)₂, CuO and CuO_0.67 films that dehydration of the outer layer having an average composition of CuO_x (OH)_2?2x proceeded with increasing anodic potential of film formation and oxidation time during growth of the duplex oxide film. Moreover, it was found that the change in PAS amplitude during cathodic reduction of the total Cu₂O film involving the inner layer to metallic copper was proportional to the electric charge required for cathodic reduction, i.e., the film thickness, irrespective of anodic potential of film formation and oxidation time, which proved the validity of the above assumption.     

Microstructure and thermoelectric properties of n-type Bi2Te2.85Se0.15 prepared by mechanical alloying and plasma activated sintering

Starting from elemental bismuth, tellurium and selenium powders, n-type Bi₂Te_2.85Se_0.15 solid solution with fine microstructure was prepared by mechanical alloying (MA) and plasma activated sintering (PAS) in the present work. The effect of PAS process on microstructure and thermoelectric properties of the sintered samples was investigated. The sintering temperature of PAS process (683 K) was 80–100 K lower than that of conventional hot pressing and the whole PAS process was also greatly shortened to about 30 min. A preferentially orientated microstructure with the basal planes (0 0 l) perpendicular to pressing direction was formed in the PASed sample and the maximum figure of merit (Z) at room temperature was 1.80 × 10⁻³ K⁻¹.     

MA-PAS和MA-HP烧结制备的Fe_3Al金属间化合物的组织和力学性能

以机械合金化Fe-28%Al（摩尔分数）合金粉末为原料,分别采用等离子活化烧结（PAS）和热压烧结（HP）方法制备致密度高达99%的Fe3Al金属间化合物。XRD和TEM测试结果表明：PAS烧结试样保留了机械合金化粉末的A2无序结构,并呈现出亚微米晶粒区域（〉1μm）和纳米晶粒区域（〈500nm）双峰分布的特征,而HP烧结试样为部分D03有序结构,晶粒尺寸在1～2μm的范围内。压缩试验表明：在室温至800℃的条件下,采用两种方法烧结的Fe3Al金属间化合物具有近似的压缩强度,虽然当温度超过400℃后压缩屈服强度均急剧下降,但在800℃时其压缩屈服强度仍高达100MPa,远高于铸造态Fe3Al金属间化合物。相比于HP烧结和铸造态Fe3Al金属间化合物,PAS烧结Fe3Al金属间化合物表现出优异的室温塑性,其室温压缩工程应变为20%。组织结构分析和力学性能测试结果表明,超细晶无序组织有利于Fe3Al金属间化合物室温塑性和高温强度的同时增强。     

Effects of MeV Fe Ions Irradiation on the Microstructure and Property of Nuclear Grade 304 Stainless Steel:Characterized by Positron Annihilation Spectroscopy,Transmission Electron Microscope and Nanoindentation

Nuclear grade 304 stainless steel was irradiated by 3.5 MeV Fe ions,with fluxes of 3.05E+ 15 ions/cm2 and 1.55E+ 16 ions/cm2.Irradiation effects were studied by positron annihilation spectroscopy (PAS),transmission electron microscope (TEM)and nanoindentation techniques.PAS results showed that different types of defects were produced after irradiation and that there was significant variance in defects formed when the samples were subjected to different irradiation doses.TEM char-acterization showed that the irradiation-induced dislocation loops enlarged in average size,but decreased in number density at higher irradiation doses.Nanoindentation test showed obvious irradiation hardening phenomenon,which was in good agreement with the PAS and TEM results.Irradiation hardening effect increased with an increase in irradiation dose and saturation occurred with an increase in irradiation dose from 3.2 to 16 dpa.Further statistical analysis showed that barrier strength of the Frank loop depends on the loop size and density produced by the ion irradiation.     

LC-MS/MS法测定对氨基水杨酸浓度及在大鼠组织分布研究中的应用

目的:开发HPLC-ESI-MS/MS方法测定大鼠组织对氨基水杨酸浓度以改善以往方法的复杂前处理过程及低灵敏度的问题,并应用于研究其在大鼠体内的分布。方法: 采用一步蛋白沉淀的前处理,选择菲诺门Synergi 4u Polar-RP 80A (150 mm×4.6 mm;4 μm)色谱柱以及梯度法进行色谱分离。内标为氯唑沙宗。采用API4000液相色谱串联质谱（LC-MS/MS）法测定。扫描方式采用多重反应监测（MRM）,负离子模式。对氨基水杨酸及内标（氯唑沙宗）监测离子对为m/z 152.0→108.1,m/z 167.9→131.9。 结果:总分析运行时间为6.5 min。对氨基水杨酸在0.05～50 μg/mL内线性关系良好,定量下限低至0.05 μg/mL。本实验方法学所有验证结果都符合FDA生物样品分析指导原则要求。结论:本分析方法准确可靠,并成功应用于临床前组织分布研究。     

Study of polymer/metal coating under stress using positron annihilation spectroscopy

Positron annihilation spectroscopy (PAS) has proven to be a very useful technique for, e.g., the study of defects in materials and the characterization of polymer free-volume. Positron lifetime, Doppler broadening of the annihilation radiation (characterized by the so-called S parameter) and angular correlation of annihilation radiation (ACAR) are the techniques used mostly. In the last few years these techniques have been extended to the study of physical defects at the atomic level of coating systems. These studies show that positron lifetime and the S parameter can monitor the degradation of the coating due to environmental changes (water or UV exposure). The present work is focused on the behavior of coatings under external stresses as studied by PAS. Results of positron annihilation measurements (before and after stretching) on interstitial free (IF) steel coated with epoxy using the Delft variable energy positron (VEP) beam facility are discussed.     

基于Dual-Kriging模型多目标稳健设计在板料拉深成形中的应用

板料拉深成形工艺中,由于设计参数波动的影响,导致在传统最优工艺条件下成形件质量不够稳健。该文采用板料成形有限元仿真、代理模型,并结合稳健设计思想,提出基于Dual-Kriging模型的稳健设计方法。筛选影响成形质量的主要模具几何、工艺参数,并确定其相应波动范围;基于有限元仿真,运用Kriging模型,建立设计参数与成形质量的函数关系;根据参数波动情况,基于第一重Kriging模型以及Monte Carlo模拟,运用Kriging模型,建立设计参数与成形质量期望与方差的第二重模型;运用基于拥挤距离的粒子群算法,以及灰色关联分析进行多目标优化,完成设计参数的稳健设计。将该方法运用于NUMISHEET 93的方盒件拉深成形,与传统确定性优化设计相比,可有效减少成形质量的波动范围以及不确定性分析的计算量,提高成形件的稳健性。     

一种基于收紧式监控技术的工艺优化算法

提出了一种新的基于收紧式监控技术的约束变尺度法,该方法是对基于Chamberlain监控技术的约束变尺度法的补充。数值试验结果表明,该法具有更高的计算效率和更优的收敛稳定性,比较适用于塑性成形的工艺优化问题。     

生物活性稀土梯度涂层在碱液环境中的电极化后处理

为了改善活性生物稀土梯度涂层的质量,在碱液环境中采用电极化处理法（PAS）对宽带激光熔覆生物活性稀土梯度涂层进行后处理。利用XRD和电化学分析仪对涂层的相组成和耐腐蚀性进行了研究,通过模拟体液浸泡试验考察了生物陶瓷涂层的生物活性和涂层表面的电荷分布情况。结果表明,碱液环境中电极化处理法（PAS）能够提高涂层的结晶度,使涂层中的非晶相、杂相向羟基磷灰石转化。PAS对涂层的耐腐蚀性影响不大。与未处理涂层相比,PAS处理后的涂层生物活性更好,且涂层表面产生了更多的负电荷。