高炉水渣微粉可抑制转炉钢渣膨胀

转炉钢渣中含有游离氧化钙（f－CaO），妨碍了转炉钢渣作为建筑材料应用。为了消除转炉钢渣中f－CaO，采用了各种处理方法，如用蒸汽陈化（现日本普遍采用此法处理转炉钢渣）等。日本NKK钢铁公司意外发现在钢渣中添加高炉水渣微粉可抑制由f－CaO引起的膨胀性。经研究发现?..     

转炉炼钢过程氧化镍直接合金化的研究

基于某钢厂现场条件，对转炉炼钢过程氧化镍直接合金化冶炼耐候钢的可行性进行了热力学分析，结果表明：铁水中固有的［C］、［Si］、［Mn］、［Fe］等均可作为还原NiO的还原剂元素，在铁水阶段和转炉阶段进行直接合金化是完全可行的。在转炉出钢温度T=1960 K，w（［C］）=0.04%条件下，［C］的还原能力比［Fe］强，镍的回收率可达到99.9%。并在实验室进行了相关的动力学实验研究，1573 K时，在铁水（含碳3%）条件下氧化镍的还原反应速率非常快，15 min后氧化镍还原反应基本完成。     

干法除尘泄爆机理分析及转炉冶炼工艺优化

唐钢长材部转炉一次除尘系统采用干法除尘工艺,该工艺流程为:冷却烟道、无"香蕉弯"蒸发冷却器、静电除尘器、离心风机、电动蝶阀切换系统等组成。干法除尘工艺对传统的转炉炼钢工艺提出了更高的要求。本文根据CO-Air-（N2/CO2）三元图的爆炸范围分析了静电除尘器泄爆机理,并结合转炉吹炼脱碳曲线阐述了转炉冶炼期间和非冶炼期间静电除尘器泄爆的原因,并提出了控制静电除尘器泄爆的措施。实践证明,通过调整和优化转炉工艺操作,可以有效控制泄爆的发生。突破了干法除尘工艺对终点w（C）<0.15%方可拉碳的技术要求,为干法除尘技术的推广应用起到示范作用。     

将粉尘和矿粉直接转化成不锈钢的新工艺

1995年初，在拉丁美洲的波多黎各岛上将动工建造一套年产32万t钢铁的生产装置。它是利用氧气顶吹转炉和鼓风炉中出来的铁矿粉和粉尘混合料作原料，直接生产不锈钢和合金钢。据美国ZiaMetallurgicalProcesses公司的人员称，由于目前鼓风炉粉尘不能有效地利用，故有好几百万吨的粉尘只能作填上处理。该项工艺的过程是这样的：先将粉尘同煤粉掺合，并加工成粒，然后在一个燃煤熔钱转炉中生产直接还原铁（DRI），将含有3％左右碳的DRI由直接还原转炉直接送入温度接近其熔点（约900C）的炼钢转炉中。然后通过Zia多功能转炉（ZAV）顶部的风…     

近年来上海的转炉炼钢

一、概况1·1 基本情况上海的转炉炼钢,解放时只有私营日亚钢厂生产侧吹酸性转炉钢,解放后,亚细亚钢铁厂(上海机械总厂前身),上钢一厂先后亦建立侧吹酸性转炉,至1956年上钢六厂建成碱性侧吹蜗鼓型转炉,经过大量试验研究工作,形成了一套操作制度,1957年以后,酸性转炉由于原料条件限制而停产,陆续建成上钢三厂一转,二转;一厂二转,三转,上钢五厂转炉车间,限于当时没有供氧条件,均采用侧吹碱性蜗鼓型转炉,使上海的转炉成为主要的产钢方法。1966年上钢一厂三转炉首先改建为30T×3的氧气顶吹转炉车间随后各厂转炉均改氧气顶吹,目前上海有四个氧气顶吹转炉车间,共12座转炉270公称吨位(宝钢除外)。见表1。1·2 上海转炉钢的产量质量品种上海的转炉钢产量一直占全国首位,到1983年,上海累计生产了转炉钢5000万吨。近几年在各转炉车间轮流大修改造的情况     

大型转炉托圈裂纹的补焊修复

正某钢厂一炼钢转炉设备为国内最大型转炉之一,于20世纪80年代由日本新日铁引进,经过近30年的使用,转炉各部件已相继进入了老化阶段。转炉托圈为转炉设备中的关键设备,托圈是否完好直接影响转炉的使用安全。由于转炉托圈的多年使用,托圈材料在交变应力下,在托圈的应力集中位置出现了开裂的     

钢生产过程简述及术语

炼钢过程是指脱碳、脱氧、脱硫和脱磷（四脱）、去气和去夹杂（二去）、调整成分和温度（二调整）。采用转炉法及电弧炉法,此外还有感应熔炼炉（IMF利用电磁感应）、真空电弧炉、电子束炉（EBF利用电子碰撞）、等离子炉（PAF利用等离子弧）等熔炼法。具体流程可分为长流程及短流程：     

不同底吹气体流量对转炉炉渣气化脱磷的影响

以65t顶底复吹转炉为研究对象,经理论计算,在1750～2000K时,P的还原产物为P2,而进一步分解为单原子磷的可能性极少,因此在溅渣期间添加碳质还原剂时,反应以方程式P2O5（1）+5C（s）=P2（g）+5CO（g）为主。同时在转炉实际生产中实验了底吹气体流量为120、350、450和550m3/h时的气化脱磷率、碱度、碳质还原剂等指标,实验表明,底吹气体量为350m3/h时气化脱磷率达到最佳值37.9%。     

从转炉烟气中回收高纯 CO 气体

日本川崎钢铁公司为了从转炉烟气中回收高纯度CO气体,作为化工原料,开发了称为COPISA(CO Pressure Induced Selective Adsorption,控制压力使CO选择吸附)的工艺,它由二级PSA(Pressure Swing Adsorption,压力变动型吸附)塔组成。因转炉烟气中各组份的吸附能力为,     

转炉溅渣护炉技术的发展及现状

溅渣护炉充分利用了转炉终渣并采用氮气作为喷吹动力,是转炉技术一个大的进步。采用溅渣护炉不仅可减少炉衬蚀损、提高炉龄,而且可减轻工人劳动强度和操作费用,提高生产率。合理控制终渣成分、留渣量、出钢温度和枪位是取得良好的溅渣护炉效果的关键技术和必备条件。我国转炉因具有容量小、数量多、生产负荷大、半钢冶炼转炉原料条件差、热源不足、复吹转炉底吹元件寿命低等特点,使得我国溅渣护炉技术朝多元化方向发展,适宜于各种炉型和原料条件以及工艺特点的溅渣护炉技术蓬勃发展,尤其在复吹溅渣护炉技术方面,已达到先进水平。但转炉经济炉龄还不确定,氮气源还不足,调渣剂的成分还不能动态调整,溅渣时间和枪位还不能自动控制,今后应积极探索终渣动态调整以及溅渣自动控制等技术。     

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。