日本高附加值线材生产工艺及品种概况

介绍日本高附加值线材的生产与品种概况:神户制钢非常注重全程管理,采用超洁净钢生产工艺,开发出6大"Only One"线材产品,其中汽车发动机阀门用弹簧钢占据世界份额的50%。新日铁住金积极参与下游线材加工厂商的产品设计开发,并进行必要的设备升级,研发出DLP在线冷却工艺,开发了省略热处理线材系列、高强度线材系列等产品。JFE在斯太尔摩冷却方法的基础上,开发出与铅浴淬火具有相同冷却能力的喷雾冷却技术,并在世界上率先使之装备化,研发了高强高韧性硬线材TMP系列、低碳高强度线材TNH系列、非调质中碳钢线材TBH系列等线材产品。     

矫直工序对MRI磁体用超导线材性能的影响

通过研究铜比7,尺寸为1.8 mm×1.2 mm线材在复绕过程中添加矫直这一冷加工变形工序,研究了矫直工艺对线材的低温性能、尺寸和绝缘电压的影响。结果表明:增加矫直工序后,对线材起到了一定的加工硬化作用,线材的RRR值和绝缘电压分别下降了7%~15%,但对线材尺寸和临界电流影响不大,对比线材的使用要求发现,经矫直工序后的线材完全可满足线材的使用要求。     

晶界对工业单晶铜线材传输性能影响的微观机制

通过分析晶界对铜线材电阻率、电容值以及信号失真度的影响规律,研究晶界对线材传输信号影响的机制.结果表明,随晶界数的增加,线材的电阻率呈非线性增加,线材的电容值呈线性减少.晶界的电阻率大于晶界两侧晶粒的电阻率是晶界影响线材传输性能的本质,晶界的电阻、电容以及电感特性是晶界对线材传输性能影响的具体表现形式.     

线材斯太尔摩风冷过程相变动力学研究及温度场预测

线材轧后斯太尔摩风冷过程对其最终组织性能非常关键,而奥氏体相变与温度场的双向耦合是线材风冷过程温度场预测的一大难题。为此,对斯太尔摩风冷过程中线材温度场及相变进行了研究,建立了线材风冷过程的三维模型及相变动力学数学模型。采用CFD模拟的方法对换热系数进行求解,发现线材搭接点区域换热系数远小于非搭接点区域,并且搭接点区域换热系数随时间呈周期性变化。通过模拟计算得出线材同一截面上下表面换热系数相差70～100 W/(m²·K)。采用有限差分法对线材相变动力学及线材在风冷条件下温度场的数学模型进行计算,得到线材温度场分布,发现线材在风冷过程中温差最大为30～50℃,与现场测量数据非常吻合,这表明模型可以用于工业生产线材风冷冷却过程温度场和相变过程的预测。     

神户钢铁公司开发出6种线材新产品

最近日本神户钢铁公司对用作汽车部件的冷镦钢线材 (ＣＨＱ)和低合金钢线材、弹簧钢线材等方面 ,开发了可大大缩短拉丝加工工序且高质量的 6种新产品。该公司开发的 6种线材新产品是 :(1 )省略拉丝前退火工序的软质线材 (低合金钢、弹簧钢 ) ;(2 )缩短球化退火时间和改善组织的细小组织线材 (ＣＨＱ) ;(3 )缩短酸洗时间的薄铁皮线材 (ＣＨＱ、低合金钢、弹簧钢 ) ;(4)简化拉丝工序的精密轧制线材 (公差 0 1ｍｍ ) ;(5 )作汽车安全部件用不易产生裂纹的线材 (ＣＨＱ) ;(6)汽车行走部件等用使用寿命长的线材 (ＣＨＱ)。这些线材新产品是使用…     

浅淡我国线材轧机的技术改造

1.目前我国线材轧机的技术状况目前我国拥有线材轧机102套,其中高速无扭线材轧机15套(引进9套,国产6套),各类复二重轧机54套,横列式轧机29套,平一立交替连续式线材轧机1套,二辊水平连续式线材轧机1套,多阶活套连续式线材轧机2套。此外,尚有5套高速无扭线材轧机正在建设中(其中国产3套,引进2套)。 1989年全国线材产量879.82×10~4t,其中高速无扭线材轧机产量193.89×10~4t。全     

Cu-Nb-C-Nb多芯复合线材的制备及表征

采用粉末套管工艺,结合集束拉拔技术制备出了石墨烯包覆铌粉末增强Cu-Nb的多芯复合线材(3#)、石墨烯未包覆铌粉末增强Cu-Nb多芯复合线材(4#)、及纯铌粉增强Cu-Nb多芯复合线材(5#) 3种结构复合线材。通过优化热处理工艺发现,线材在750℃/60h热处理后,与线材的Nb (110)衍射峰强度相比加工态样品发生了明显的增强。微观结构及EDS能谱分析说明,高温热处理有利于Cu/Nb界面之间的轻微扩散,增加了界面的结合强度,线材的塑性和韧性得到了明显改善。通过对3种线材微观结构、力学性能及电学性能的分析表明,石墨烯包覆铌粉末的Cu-Nb-C-Nb线材导电性能优于其它2种线材。最后,分析了3种不同线材的塑性变形机制及引起性能变化的微观机理。提出了进一步优化工艺,为高强高导多元结构复合线材的制备开创了一种全新的方向。     

高速线材轧机用铸铁辊环的材质

高速线材轧机用铸铁辊环的材质戴樵（太原钢铁公司轧辊机修厂山西太原市：０３０００３）主题词：线材、轧机，辊环，冷硬铸铁高速线材轧机是轧钢生产中轧制线材的先进设备。１９８６年以来，我国进口的第二代、第三代和自行设计的高速线材轧机相继投入使用，其最大出口速...     

新日本钢铁公司室兰厂完成线材轧机的现代化改造

新日本钢铁公司室兰厂最近完成了线材轧机的现代化改造工程,于1992年3月14日开始正式投入生产。该线材轧机于1969年9月建成,是日本第1套垂直—水平式连续线材轧机,为单线轧制,主要生产弹簧用线材和高级琴钢丝用线材等各种高质量线材产品。其后,于1985年进行了设备更新,即新建了无扭     

我国线材品种质量的优化与展望

从线材用户的角度论述了近十年来我国线材生产取得了长足的进步，但与国外先进水平相比仍存在着质量、品种上的差距。展望未来十年，提出应提高高碳钢及特殊钢线材比例，对尚不能满足要求的产品品种、质量应再优化。由此建议再建１０条高速线材生产线，最好引进１～２条更高水平的高速线材轧机。     

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。