张力辊理论设计方法研究

针对带钢精整机组中张力辊参数传统的计算方法过多依靠经验问题,本文以张力辊组各辊子寿命相等为原则,研究张力辊的理论设计方法。建立了辊径计算模型、张力放大计算模型、包角损失计算模型、带钢弹塑性弯曲引起的张力损失计算模型、带钢离心力计算模型和传动功率计算模型,将六个模型耦合迭代,理论计算了张力辊辊径、传动电机功率等工艺参数,提高了张力辊组整体寿命。     

连续处理机组入口带尾自动准确停车计算

本文就连续处理机组入口带尾准确停车进行了设计计算,主要介绍了卷径的计算、剩余带钢长度的计算、设定带钢长度的计算、剩余带钢长度与设定带钢剩余长度的比较,相对于传统计算方式,此设计计算能使入口带尾自动停车更加准确。     

张力辊理论设计方法研究

针对带钢精整机组中张力辊参数传统的计算方法过多依靠经验问题,本文以张力辊组各辊子寿命相等为原则,研究张力辊的理论设计方法.建立了辊径计算模型、张力放大计算模型、包角损失计算模型、带钢弹塑性弯曲引起的张力损失计算模型、带钢离心力计算模型和传动功率计算模型,将六个模型耦合迭代,理论计算了张力辊辊径、传动电机功率等工艺参数,提高了张力辊组整体寿命.     

基于Excel的孕镶金刚石钻头胎体配料计算

介绍了孕镶金刚石钻头在设计制造过程中配料计算的原料选择原则,给出了Excel实现配料计算的计算原理,及各项组分的计算程序、计算公式和Excel单元格计算公式实现。对计算结果的比较分析表明:该程序计算结果准确、操作简便,能快速显示计算结果并直接打印,有利于钻头生产的配料改进和数据的科学管理。     

基于变参数坡口模型分层焊材消耗计算

焊材消耗用量计算是焊接工艺设计的重要内容.在双边双面U形坡口参数描述的基础上,改变参数演变为其它常见类型坡口,实现常见坡口类型统一化参数模型,便于焊缝截面面积计算.通过对该模型焊缝横截面分解,将复杂截面面积求解简化为简单图形面积计算,计算各焊接工序焊材消耗用量必须求解对应焊层横截面面积,提出了焊层截面面积计算思想并给出基于焊层厚度横截面面积计算理论,在此基础上设计了分层的迭代计算算法并开发了软件计算工具,说明了软件使用方法,测试计算了一个实际坡口焊材用量.结果表明,能够显著提高焊材计算精度和效率.     

焊接理论——一般问题

焊材消耗用量计算是焊接工艺设计的重要内容。在双边双面U形坡口参数描述的基础上,改变参数演变为其它常见类型坡口,实现常见坡口类型统一化参数模型,便于焊缝截面面积计算。通过对该模型焊缝横截面分解,将复杂截面面积求解简化为简单图形面积计算,计算各焊接工序焊材消耗用量必须求解对应焊层横截面面积。提出了焊层截面面积计算思想并给出基于焊层厚度横截面面积计算理论,在此基础上设计了分层的迭代计算算法并开发了软件计算工具,说明了软件使用方法,测试计算了一个实际坡口焊材用量。结果表明,能够显著提高焊材计算精度和效率。图5表1参3     

风力发电机组内铸件的强度分析计算

风力发电机组内铸件的强度分析计算,主要包括极限强度和疲劳寿命计算。铸件的极限强度计算采用有限元法进行,以轮毂为例介绍铸件的极限强度计算。铸件疲劳寿命的计算分为两个部分,即单位载荷下铸件的应力分析计算和根据铸件所承受载荷的疲劳载荷谱和单位载荷下应力值进行疲劳损伤值的雨流统计计算。     

焊接理论——一般问题

焊材消耗用量计算是焊接工艺设计的重要内容。在双边双面U形坡口参数描述的基础上,改变参数演变为其它常见类型坡口,实现常见坡口类型统一化参数模型,便于焊缝截面面积计算。通过对该模型焊缝横截面分解,将复杂截面面积求解简化为简单图形面积计算,计算各焊接工序焊材消耗用量必须求解对应焊层横截面面积。提出了焊层截面面积计算思想并给出基于焊层厚度横截面面积计算理论,在此基础上设计了分层的迭代计算算法并开发了软件计算工具,说明了软件使用方法,测试计算了一个实际坡口焊材用量。结果表明,能够显著提高焊材计算精度和效率。图5表1参3     

基于快速计算方法的汽车厚板料零件结构工艺性研究

通过深入研究快速计算方法的基础理论及其对工艺、计算方面的简化和假设,给出了该计算方法的适用条件,即应变路径线性条件,汽车上绝大部分弯曲、压形、翻边和简单拉延的零件都满足上述条件。从最满足线性加载条件的、简化和假设最少并且产品设计中出现问题较多的伸长类翻边结构入手,利用精确计算结果对快速计算结果及参数设定进行测试和校准,并给出该计算方法的评判标准和注意事项。通过计算结果对比可知,精确计算与快速计算偏差在±10%以内,因此利用快速计算方法进行伸长类翻边结构的工艺评审是可行的。     

难变形金属棒线材连轧机孔型设分计算界面的开发

三辊Y型连轧机的孔型设计与参数计算,直接影响着难变形金属棒线材生产线的正常工作及工作效率,尤其是孔型参数的计算。目前,国内在这一领域几乎还没有较为系统的计算软件。本文介绍了用于轧制难变形金属的三辊Y型连轧机孔型设计计算界面的开发,计算结果表明,用计算界面算出的数据与实际使用的数据非常接近,说明该计算界面完全可以用于三辊Y型连轧机的孔形设计与计算。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。