用连续热轧装置生产热轧钛卷的方法

本发明揭示了连续热轧钛卷的生产方法。其工艺特点是:将钛坯在炉内加热到700～950℃然后进行热轧,热轧钛带在450℃以上卷取成卷,当卷取终轧钛带的头部时,其尾部仍在精轧机轧辊轧制。     

1725mm双机架炉卷轧机机架的铸造

详述了1725mm双机架炉卷轧机生产过程,在冶炼、铸造和热处理的工艺设计中,通过优化工艺,对传统工艺模式进行了创新,并成功地生产出1725min双机架炉卷轧机机架。     

常规热轧带钢轧机粗轧工序轧制工艺研究

介绍了一种新的常规热轧带钢轧机粗轧工序的轧制工艺与设备组成,并与现有的几种半连续式轧制工艺在生产能力、带坯温度、轧线长度等方面进行了计算、分析和比较,该串列式双机架可逆式粗轧机组能缩短粗轧区的轧线长度,节省占地和投资,提高粗轧机组产能,既适用于新建项目,又适用于采用单机架可逆式粗轧机的旧厂扩产改造。     

提高线材几何尺寸精度的新措施——中轧机组采用2个三辊孔型机架

提高线材和小圆钢几何尺寸精度的主要途径有3种:①安装预应力机架;②安装两辊式精轧机组;③稳定轧制过程各工艺参数(应力、温度、横断面等)。安装预应力机架不能根本解决尺寸精度     

中厚板炉卷轧机发展分析

分析了板卷轧机因吸取热连轧机和常规中厚板轧机的控制技术,而发展较快,尤其是以卷轧方式生产中厚板且生产宽规格热轧卷的炉卷轧机的发展,形成了现代卷轧中厚板轧机的技术特色.具体介绍了板卷轧机的特点、生产工艺、采用的主要技术、典型轧机概况,并与常规中厚板轧机进行了比较.同时对大型钢铁企业建中厚板炉卷轧机如何合理分工,其设备配置、参数选择等进行了探讨.     

基于MVC的双机架炉卷轧机轧制力矩的仿真研究

在双机架炉卷轧机带钢热轧过程中,轧制力矩数据是否合理直接影响轧制成品的质量。运用计算机软件Visual Studio,开发出基于MVC框架的双机架往复式炉卷热轧机轧制力矩网络仿真系统,并设计了轧制力矩的相应仿真模块以及对轧制力矩进行网络仿真。仿真结果表明轧制力矩相对误差在很小范围以内变化,结果对实际轧制生产具有指导作用。     

谈现代炉卷轧机（二）

简要介绍了炉卷轧机的特征,按生产的产品和布置型式对现代炉卷轧机进行了分类;讨论了生产线上主要设备机型应具备的功能,双机架炉卷轧机立辊机架的配置、生产工艺、自动化以及“卷板”工艺国产化等技术问题。     

3 500 mm炉卷轧机轧制5 mm厚钢板生产实践

江阴兴澄特种钢铁有限公司通过对坯料准备、加热与轧制工艺、轧辊辊型、轧制规程以及生产计划编排等的调整, 在3 500 mm炉卷轧机上成功生产出了5 mm×3 150 mm薄规格钢板, 钢板板形、板凸度良好, 生产稳定。     

3.0mm以下热轧薄规格宽带钢的开发

针对常规热连轧生产线开发薄规格带钢过程中通常遇到的加热温度、轧机设备精度、轧机负荷及各机架间的负荷分配、板形控制系统等制约因素,莱钢银山型钢有限公司板带厂通过采取钢坯前端低温加热、后端高温加热,均衡轧制节奏并建立适宜的轧辊热凸度,优化烫辊制度和轧制单位编排制度,优化精轧负荷分配方式和负荷分配参数,开发基于现场生产线的精轧模型仿真平台,调整辊型及辊温控制,降低卷取张力等措施,实现了厚3.0mm以下薄规格带钢的批量生产,且带钢厚度命中率达95.03％,通条凸度、楔形指标平均达标率达98.1％,平直度平均达标率为98.4％.     

3.0mm以下热轧薄规格宽带钢的开发

针对常规热连轧生产线开发薄规格带钢过程中通常遇到的加热温度、轧机设备精度、轧机负荷及各机架间的负荷分配、板形控制系统等制约因素,莱钢银山型钢有限公司板带厂通过采取钢坯前端低温加热、后端高温加热,均衡轧制节奏并建立适宜的轧辊热凸度,优化烫辊制度和轧制单位编排制度,优化精轧负荷分配方式和负荷分配参数,开发基于现场生产线的精轧模型仿真平台,调整辊型及辊温控制,降低卷取张力等措施,实现了厚3.0mm以下薄规格带钢的批量生产,且带钢厚度命中率达95.03%,通条凸度、楔形指标平均达标率达98.1%,平直度平均达标率为98.4%。     

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。