转炉钢包车控制系统及出现故障处理方法

本文介绍了WJQ - 1交流无触点启 /制动器在转炉钢包车控制系统的应用。论述了该控制器的可靠性、实用性及稳定性 ,并详细说明了该系统的控制过程及故障处理方法 ,对转炉钢包车的电气设备维护具有一定意义     

利用电动液压制动器取代交流电磁铁制动器

利用电动液压制动器取代交流电磁铁制动器广东省韶钢集团公司陈延春１前言在这个技改项目实施以前，焦化厂的天车刹车系统均为由电磁铁制动器组成的刹车系统，由于交流电磁铁制动器本身内在因素，不能很好地满足生产要求，从而寻求一种新的刹车系统一分必要。电动液压刹车...     

AGC系统控制模型与结构的研究

针对几种厚度自动控制系统（ＡＧＣ系统）控制模型的特点，分析，研究了各种ＡＧＣ控制模型对系统结构的特殊要求，并给出基本的系统结构。对各种ＡＧＣ控制模型及系统之间的关系做了推导和比较。     

热连轧机基础自动化系统控制和算法的特点

本文介绍攀钢热轧板厂热连轧机基础自动化系统的配置、功能和控制算法的特点。着重阐述活套和卷取机张力控制、ＰＩＤ闭环控制、ＡＰＣ和ＡＧＣ控制、带钢尾部定位，精轧速度主令等自动控制和算法的特点，并提请读者注意在设计和调试类似系统时应注意的若干问题。     

CO2气体保护焊在高炉炉壳焊接上的应用

阐述ＧＥＣＮＣ０１数控系统结构原理、ＰＣ／２８６控制下软硬件结构、特点以及位置伺服、速度控制、零件加工程序的输入、解释等关键技术的实现；简单介绍系统的及经济效益，简要分析用通用计算机作为数控主机的先进性及存在的缺点。     

直进式拉丝机变频调速系统的设计

在直进式拉丝机上采用了ＰＣ闭环控制交流变叔调速系统，介绍了这一控制系统的控制科及控制原理，并通过建立拉拔过程的数学模型获得了系统的控制规律，实现了生产过程的自动控制。     

Smith预估控制策略在AGC系统中的应用

介绍一种新型的ＡＧＣ系统－Ｓｍｉｔｈ－ＡＧＣ系统。给出系统结构；对控制自适应增益算法进行了推导；对系统稳定性进行了分析并给出Ｓｍｉｔｈ－ＡＧＣ系统稳定的充分必要条件。该ＡＧＣ系统已用于本钢冷连轧机；统计分析表明，成品相对厚度精度优于±１％。     

一种改进型纯滞后预估补偿方法

本文介绍了一种改进型纯滞后预估补偿方法，它由队衍，乘法计算环节，预估补偿模型和调节器组成，主要技术特征是预估补偿模型为ｅ＾－τｓｍ取消了史密斯（Ｊ．Ｍ．Ｓｍｉｔｈ和盖莱斯（Ｒ．Ｆ．Ｇｉｌｅｓ）预估模型中的惯性特性ＫｍＧｍ（Ｓ）和超前作用环节１＋τ．ｓ。系统功能元件少，结构简单可实现高精度调节，并简略地说明史密斯和盖莱斯模型之不足和改进之后传递函数的推导和实用场合。     

采用PC机集中保护电机断相

采用ＰＣ机集中保护电机断相随着ＰＣ机控制范围的不断扩大，原先复杂的设备流程连锁运转控制也逐步使用了ＰＣ机。我分厂烧结系统１９８６年改造采用美国贝利公司Ｎ－９０集散控制系统控制，因该系统运行近七年多；电子元器件老化，设备的维修费用越来越高，并且备件不能...     

宝钢03线钢卷运输系统故障分析

对宝钢连接热轧厂和冷轧厂的钢卷运输系统电气部分存在的问题和常发故障，进行了较全面的分析与研究，并在ＡＥＧ的原系统上附加一套测定装置，同时修改了ＡＥＧ计算机软件，解决了系统存在的撞车，拒动，磨电道漏电保护跳闸等问题。在现场的实际应用取得了良好的效果。     

Effect of carbon concentration on precipitation behavior of M<Subscript>23</Subscript>C<Subscript>6</Subscript> carbides and MX carbonitrides in martensitic 9Cr steel during heat treatment

The distributions and precipitated amounts of M₂₃C₆ carbides and MX-type carbonitrides with decreasing carbon content from 0.16 to 0.002 mass pct in 9Cr-3W steel, which is used as a heat-resistant steel, has been investigated. The microstructures of the steels are observed to be martensite. Distributions of precipitates differ greatly among the steels depending on carbon concentration. In the steels containing carbon at levels above 0.05 pct, M₂₃C₆ carbides precipitate along boundaries and fine MX carbonitrides precipitate mainly in the matrix after tempering. In 0.002 pct C steel, there are no M₂₃C₆ carbide precipitates, and instead, fine MX with sizes of 2 to 20 nm precipitate densely along boundaries. In 0.02 pct C steel, a small amount of M₂₃C₆ carbides precipitate, but the sizes are quite large and the main precipitates along boundaries are MX, as with 0.002 pct C steel. A combination of the removal of any carbide whose size is much larger than that of MX-type nitrides, and the fine distributions of MX-type nitrides along boundaries, is significantly effective for the stabilization of a variety of boundaries in the martensitic 9Cr steel.     

IF钢搪瓷板析出相的研究

2001年武钢开始生产冷轧IF钢搪瓷板，为了解IF钢瓷板成分设计的合理性和优化生产工艺，在透射电镜上观察了钢中析出相的形态，用能谱仪分析了析出相的成分，并对析出相的平衡进行了计算。研究结果表明：IF钢搪瓷板中的析出相主要为TiS、Ti4C2S2、TiN以及细小的FeTiP相；钢的碳含量增加和低的热轧加热温度有助于Ti4C2S2相的析出；钢中富余的固溶Ti将在退火温度下形成FeTiP相，粗大的TiS、Ti4C2S2析出相，既使钢板具有良好的涂搪性能，又对钢的深冲性能无有害影响，因此，IF钢搪瓷板具有很好的涂搪性能和深冲性能。     

氮在非调质钢中的作用

了氮在非调质钢中所起的有益作用。在Ｎｂ,Ｖ,Ｔｉ三咱微合金化元素中,钒有较高的溶解度,钒有较高的溶解度,是非调质钢最常用也是最有效的强化元素。钒在钢中通过形成细小析出相起细化晶粒和沉淀强化作用。与碳相比,氮与钒有更强的亲和力,且氮化物更稳定,因此,氮对控制钒的析出起更重要的作用。大量研究结果表明,非调质钢中增氮改变了钒在相间的分布,促进Ｖ（Ｃ,Ｎ）析出,使析出相的颗粒尺寸明显减小。因而氮增强了非调     

Precipitates and Hydrogen Permeation Behavior in Vanadium-Bearing Microalloyed Low Carbon Steel

The precipitates and hydrogen permeation behavior were studied in the low carbon steel for enameling.During the preparation of samples,Ti containing and Ti free in vanadium-bearing microalloyed low carbon steel heating at 750℃ for 3 h,were adopted after cold-rolling.It was found that the a large number of fine VC,TiC,TiN and Ti 4 C 2 S 2 precipitates were in samples of Vanadium-bearing microalloyed low carbon steel with Ti element.And fine VC,Fe 3 C and MnS precipitates were in steels without Ti element.So the numbers of precipitates in the former is more bigger than the later.The activation energies for hydrogen diffusion in both samples are 26.5 and 23.7 kJ/mol,respectively.But at 25℃,the effective diffusion coefficients in the samples for Ti containing and Ti free in Vanadium-bearing microalloyed low carbon steel were measured as 2.71×10-6 and 4.22×10-6 cm 2 /s,respectively.No fishscaling defect occurred in the former and heavy fishscaling defect in the later.     

Diffusion alloying – a new manufacturing method for PM tool steels

Abstract

To increase the wear resistance of tool steels, high contents of super-hard MC type carbides formed by Ti, V or Nb are desirable. Unfortunately, these carbides precipitate primarily from the melt at high temperatures. Thus, atomising such steels is not feasible with current technology because carbides precipitating in the melt may clog the nozzle. This problem can be avoided by atomising a melt that contains high amounts of carbide forming elements but no carbon. Subsequently the powder is mixed with graphite to provide the carbon necessary to form carbides and for the hardenability of the matrix. During hipping, graphite dissolves and the carbon is distributed evenly in the material. The phase distribution of a candidate cold work tool steel consisting of a stainless steel matrix with fine, well distributed niobium carbide precipitates is reported and compared with equilibrium calculations.     

Precipitation of AIN and MnS in Low Carbon Aluminium-Killed Steel

 Abstract： The precipitation kinetics of AlN and MnS in low carbon aluminium-killed steel was calculated. Transmission electron microscopy (TEM), energy disperse spectroscopy (EDS) and phase analyses have been used to investigate the morphology, compositions and particle size distribution of AlN and MnS precipitates in three positions of the coil. The particles of AlN and MnS precipitates in the ferrite region after coiling and distributes along and adjacent to the ferrite grain boundaries. The shapes of AlN are plate-like, the precipitates size is about 10 to 60 nm; the shapes of MnS are spherical, the precipitates size is about 200 to 600 nm. The precipitation behavior of AlN is sensitive to the isothermal temperature and holding time, the precipitation quantity and particle size distribution of AlN in different positions of coil are unequal.     

Carbonitride precipitation in niobium/vanadium microalloyed steels

A detailed study of carbonitride precipitation in niobium/vanadium microalloyed steels is presented. A thermodynamic model is developed to predict the austenite/carbonitride equilibrium in the Fe-Nb-V-C-N system, using published solubility data and the Hillert/Staffansson model for stoichiometric phases. The model can be used to estimate equilibrium austenite and carbonitride compositions, and the amounts of each phase, as a function of steel composition and temperature. The model also provides a method to estimate the carbonitride solution temperatures for different steel compositions. Actual carbonitride precipitation behavior in austenite is then examined in two experimental 0.03Nb steels containing 0.05V and 0.20V, respectively. Samples were solution treated, rolled at 954 °C (20 pct or 50 pct), held isothermally for times up to 10,000 seconds at 843 °C, 954 °C, or 1066 °C, and brine quenched. The process of carbonitride precipitation in deformed austenite is followed by analytical electron microscopy (AEM) of carbon extraction replicas. Precipitates are. observed at prior-austenite grain boundaries, and also within the grains (presumably at substructure introduced by the rolling deformation). Analysis of the grain-boundary and matrix precipitate compositions by AEM indicates that the grain-boundary precipitates are consistently richer in vanadium than the matrix precipitates, although compositional trends with holding time and temperature are similar for the two types of precipitates. The compositions of both the grain-boundary and matrix precipitates are not significantly influenced by the rolling reduction or the holding time at temperature. As predicted by the thermodynamic model, the precipitates become more vanadium-rich as the vanadium level in the steel is increased and as the temperature is reduced. The agreement between the measured and predicted precipitate compositions is quite good for the grain-boundary precipitates, although the matrix precipitates are consistently more niobium-rich than predicted by the model.     

Carbonitride precipitation in niobium/vanadium microalloyed steels

A detailed study of carbonitride precipitation in niobium/vanadium microalloyed steels is presented. A thermodynamic model is developed to predict the austenite/carbonitride equilibrium in the Fe−Nb-V-C-N system, using published solubility data and the Hillert/Staffansson model for stoichiometric phases. The model can be used to estimate equilibrium austenite and carbonitride compositions, and the amounts of each phase, as a function of steel composition and temperature. The model also provides a method to estimate the carbonitride solution temperatures for different steel compositions. Actual carbonitride precipitation behavior in austenite is then examined in two experimental 0.03Nb steels containing 0.05V and 0.20V, respectively. Samples were solution treated, rolled at 954°C (20 pct or 50 pct), held isothermally for times up to 10,000 seconds at 843°C, 954°C, or 1066°C, and brine quenched. The process of carbonitride precipitation in deformed austenite is followed by analytical electron microscopy (AEM) of carbon extraction replicas. Precipitates are observed at prior-austenite grain boundaries, and also within the grains (presumably at substructure introduced by the rolling deformation). Analysis of the grain-boundary and matrix precipitate compositions by AEM indicates that the grain-boundary precipitates are consistently richer in vanadium than the matrix precipitates, although compositional trends with holding time and temperature are similar for the two types of precipitates. The compositions of both the grain-boundary and matrix precipitates are not significantly influenced by the rolling reduction or the holding time at temperature. As predicted by the thermodynamic model, the precipitates become more vanadium-rich as the vanadium level in the steel is increased and as the temperature is reduced. The agreement between the measured and predicted precipitate compositions is quite good for the grain-boundary precipitates, although the matrix precipitates are consistently more niobium-rich than predicted by the model.     

Matrix Dissolution Techniques Applied to Extract and Quantify Precipitates from a Microalloyed Steel

Microalloyed steels possess good strength and toughness, as well as excellent weldability; these attributes are necessary for oil and gas pipelines in northern climates. These properties are attributed in part to the presence of nanosized carbide and carbonitride precipitates. To understand the strengthening mechanisms and to optimize the strengthening effects, it is necessary to quantify the size distribution, volume fraction, and chemical speciation of these precipitates. However, characterization techniques suitable for quantifying fine precipitates are limited because of their fine sizes, wide particle size distributions, and low volume fractions. In this article, two matrix dissolution techniques have been developed to extract precipitates from a Grade100 (yield strength of 690 MPa) microalloyed steel. Relatively large volumes of material can be analyzed, and statistically significant quantities of precipitates of different sizes are collected. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) are combined to analyze the chemical speciation of these precipitates. Rietveld refinement of XRD patterns is used to quantify fully the relative amounts of the precipitates. The size distribution of the nanosized precipitates is quantified using dark-field imaging in the TEM.     

热轧带钢卷带及其冷却过程AlN沉淀析出模拟研究

模拟研究了热轧普碳钢带在卷后冷却过程中 Al N沉淀析出的情况及其对热轧钢带最终力学性能的影响 ,结果表明 ,在相同冷却速率条件下 ,卷带温度越高 ,Al N沉淀析出量越多 ,固溶氮越少。冷却速率越快 ,Al N沉淀析出量越少 ,固溶氮越多。不同的工艺参数条件下 ,可以获得相同的 Al N沉淀析出效果。