Fushun Steel Plant

Fushun Steel Plant is situated at thewestern part of Fushun city, Liaoning Pro-vince, 45 km from Shenyang. It is one ofthe major special steel plants in China.Established in 1937, Fushun Steel Planthas had a history of more than half century.Before 1948 it was a small-scale plant.From 1937 to 1948 the total steel productionwas only 58000 t. After foundation of PRCthere have been two stages of reconstruction;after the 1st stage (1958 to 1962) the plantbecame the first production base of su-peralloy and stainless steel in China: from1978 to 1983 (second stage) five sets oflarge advanced melting and hot workingequipment and ten sets of measurement

Analysis and Response of Steel Stacking Accidents in Hot Rolling Coilers

Through long-term production and maintenance practice,various types of stacking steel in the 2250mm hot rolling coiler of Ma Steel were tracked and analyzed,and the causes of stacking steel were summarized.Cor-responding measures were formulated to effectively reduce the probability of stacking steel.

Effect of Ce on the cleanliness, microstructure and mechanical properties of high strength low alloy steel Q690E in industrial production process

In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic microscope.The results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation alone.The inclusions were spheroidizing.The size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was dispersed.Ce played a role in purifying molten steel through desulphurization and deoxidization.Meanwhile,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar crystals.The average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled plate.In addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was obtained.When rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening effect.Mechanical properties such as tensile,yield,and low-temperature impact toughness were significantly improved.

Determination and Analysis of Hardenability for Hot-Forging Die Steels with Deep-Hardening

ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was measured and the tempering resistance was studied.It was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring.

Enhanced clean steel tapping on BOF vessels with the interstop converter gate type CG series

Trends in today' s steel production show increasing demands for highly-sophisticated steel grades. Therefore,the steel industry will eventually be required to install best performing technologies to meet governmental specifications designed to significantly reduce environmental emissions.Such efforts are supported by innovative new solutions in the entire steel making process.One process that will need to be addressed is the cleanliness of the steel in the liquid steel phase,especially during the BOF-tapping process. The new converter gate(CG)(Fig.1) best supports the slide gate tapping technology for converters in terms of clean steel,productivity,yield and availability-at reduced costs. The CG gate introduces a unique feature for converter slide gates:The bottom plate can be exchanged while the gate remains mounted on the converter.This new feature allows for an increased utilisation of the refractory parts and a significant reduction of the downtime of the converter.This 'designed efficiency' is achieved with a refractory set consisting of three identical plates-two bottom plates and one slider plate-and a nozzle.A number of other improvements such as automatic cylinder coupling using the Interstop SNAP technology and a two step tensioning system have also been implemented. The new system is designed to meet minimal space requirements and therefore will adapt to most BOF shops.To perform preparation,service and maintenance work the modular CG gate can be dismounted from the converter and simultaneously replaced by a ready-to-use unit.The degree of automation for dismounting and mounting as well as for off-line preparation has been enhanced and reduces manual efforts. This paper provides a solution to the obvious trend towards efficient and controlled production of clean steel,in general,and especially at BOF shops.Moreover,it specifically describes the operational results of this innovative BOF tapping equipment at Salzgitter Flachstahl GmbH,Germany.

Effect of electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting

An investigation on the influence of low frequency rotary electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting was experimentally conducted and carried out on an industrial trial basis. The results show that application of appropriate electromagnetic stirring parameters can obviously improve the macrostructure of austenitic stainless steel, in which both columnar and equiaxed grains can be greatly refined and shrinkage porosity or cavity zone along centerline can be remarkably decreased due to eliminating intracrystalline and enlarging equiaxed grains zone. The industrial trials verify that the electromagnetic stirring intensity of austenitic stainless steel should be higher than that of plain carbon steel. Electromagnetic stirring has somewhat affected the macrostructure of austenitic stainless steel even if the magnetic flux density of the electromagnetic stirring reaches 90 mT （amplitude reaches 141 mT ） in average at frequency f=3-4Hz, which provides a reference for the optimization of design and process parameters when applying the rotary electromagnetic stirrer.

The development and application of premium thread connection tubing and casing products from Baosteel

Premium thread connection tubing and casing products are non-API products that are used in severe oil field conditions, such as deep wells ,ultra deep wells, high pressure gas wells, horizontal wells and steam injection wells, etc. In order to meet the requirements of oilfields for premium thread connection oil country tubular goods （ OCTG）, Baosteel developed its own series of premium thread connection tubing and casing products that are protected by intellectual property rights. This study introduces the process of developing the premium thread connection tubing and casing products, their characteristics, and their actual application in oil fields. It hopes to give customers a better understanding of Premium thread connection tubing and casing products from Baosteel.

Evolution of Nonmetallic Inclusion during Steelmaking Process of Cold Heading Steel SWRCH35K

In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al2O3 →MgO·Al2O3 →CaO-MgO-Al2O3-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213#/mm2, while the number of inclusions at the end of LF refining is the least, about 12#/mm2, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting.

氮元素对高钛含铌钢裂纹影响的定量研究

应用试验、热力学计算及统计,定量研究了氮(N)对高钛(Ti)含铌(Nb)钢连铸横裂纹的影响,提出N控定量标准。结果表明:高钛含铌钢的高温塑性与氮化物形成具有强相关性;凝固末期TiN的析出影响第一脆性区,第二脆性区与Nb(C,N)的析出有关,温度区间为从Nb(C,N)析出到其析出速率开始缓和的温度,第三脆性区与铁素体或AlN析出有关,温度区间为从铁素体或AlN析出到渗碳体开始析出的温度。高钛含铌钢的N控瓶颈在于TiN在凝固末期的析出,根据Ti、N积建立控N标准,Ti、N积为4×10-5~7×10-5(%•%)。

轨道交通用钢中Ds夹杂物特征及控制

为有效控制轨道交通用钢中夹杂物危害,借助扫描电镜和能谱分析对钢中DS夹杂物特征进行了分析。Ds夹杂物形状呈现典型球形,夹杂物成分主要为钙铝酸盐,尺寸在206μm左右,且周围包裹一层CaS夹杂物。通过对生产过程关键技术指标的分析,认为形成该类DS夹杂物主要原因为钙处理过程夹杂物上浮去除时间不足以及RH过程中Alt收得率低。通过优化改进钙处理工艺及RH运行工艺和洗槽工艺,取得明显效果,实现了钢中Ds夹杂物有效控制。

基于轧制规程优化的冷轧机轴向力治理方法

针对国内某冷连轧机组中间辊推力轴承频繁损坏的问题,通过分析机组设备磨损和安装精度等影响因素,确定由于衬板磨损使中间辊轴线偏移进一步造成轴向力过大,导致轴承工作过程中偏载和发热严重,并且最终损坏。为此,基于中间辊轴线偏移即轧辊交叉导致中间辊与其他轧辊产生相对位移的几何分析,结合两粗糙弹性零件接触的预位移原理,并应用金属塑性变形模型和轧辊弹性变形模型,分别建立轧辊接触区内黏滞区和滑动区的单位轴向力计算方法,最终实现中间辊总轴向力的预报。在此基础上,考虑中间辊与工作辊及中间辊与支撑辊的辊间力分布对轴向力的影响,确定了以降低边部辊间力为基础优化轧制规程的治理思路。提出了辊间力分布的评价指标,并进一步确定了中间辊轴向力治理的目标函数,以出口板形、轴向力、辊间力分布评价指标为约束条件,建立了中间辊轴向力的治理技术。将轴向力预报模型应用到冷连轧机组并对比实测值和预报值,以典型钢种S350GD+AZ为例,结果表明预报模型在各机架的计算偏差均小于8%。将轴向力治理技术应用到冷连轧机组,并对比治理前后的各工艺参数,表明在保证出口板形的前提下大幅度降低了各机架中间辊轴向力,有效避免了中间辊轴向力过大导致的轴承损坏问题,保证了机组的稳定生产。

基于深度置信网络和SVM的铣刀磨损状态识别

针对人工提取的磨损指标无法全面表达铣削磨损特征的问题,提出基于改进深度置信网络(IDBN)与支持向量机(SVM)的刀具磨损识别模型。首先对刀具切削力、振动和AE信号在时域、频域、时频域进行特征提取;其次采用IDBN对提取的特征降维;最后利用改进的海鸥算法优化支持向量机(ISOA-SVM)构建磨损识别模型。结果表明,经过100次随机分层抽样,IDBN-ISOA-SVM对刀具磨损的平均识别率达到99%以上。从降维手段、优化算法及分类模型三个方面与其他算法对比,该模型有较高的识别率和泛化性,能够准确识别铣刀磨损状态。

白云鄂博矿中稀土镧在高炉炼铁过程的传承机理

文章以稀土镧为对象,研究了白云鄂博矿中稀土元素镧在高炉炼铁过程的传承机理。通过热力学计算和实验表征分析了高炉炼铁过程中镧元素在渣-铁之间的微观行为。结果表明,高炉渣中的La_(2)O_(3)在高炉炼铁过程中可以被还原成LaC_(2),随后LaC_(2)溶于铁水中且镧被多孔状石墨上的含氧官能团吸附,从而使稀土能够传承到后续的炼钢工艺过程中。弥补了传统观点认为的高炉渣中稀土氧化物在高炉炼铁时很难被还原,无法继续往后续流程传承的问题。

张力减径张力系数对无缝钢管壁厚不均的影响

通过观察内孔形状及测量壁厚对无缝钢管壁厚精度情况进行研究;采用电子扫描显微镜对合金微观组织进行分析。结果表明:张力减径过程中采用大张力系数配合等壁或减壁方式进行轧制,可有效改善无缝钢管壁厚的均匀性,提高壁厚精度。采用大张力系数进行轧制的无缝钢管的组织呈现均匀分布的特征。

转炉高效冶炼工艺技术的研究和开发

通过研究炉渣渣系及炉内反应动力学,实施留渣及全留渣工艺达50%以上,优化了炉渣渣组元浓度(如MgO、R)、加料方式等,形成了具有“快速成渣、维持低熔点及良好流动性”的全新加料操作模式。结果表明:采用少渣冶炼工艺后炉渣碱度2.80,石灰单耗降低了13.48%,脱磷率提升2.02百分点;冶炼过程炉渣“喷溅”、“返干”频次明显减少,供氧时间缩短(降低氧耗),该工艺具有可观的降成本潜力,具备广泛的推广价值。

近二十年宝钢RH装备及技术进步

在汽车板、硅钢、镀锡板、管线钢、船板等高等级品种钢开发和质量提升需求的推动下,近二十年来宝山基地在RH精炼装备、工艺技术及自动化等方面取得了长足的进步,特别在RH真空精炼装备、高效脱碳、低成本处理、顶枪真空加热、夹杂物控制、RH专线化生产、环保耐材、RH智能一键精炼等方面形成了具有自身特点的工艺技术,满足了品种钢开发、质量提升和产能提高的需求。

降低太钢AOD炉和钢包用耐火材料单耗的控制措施

介绍了在耐火材料区域整体承包模式下,钢铁企业关注的指标不仅仅只是耐火材料吨钢成本,更要重点关注耐火材料吨钢消耗指标,降低耐火材料吨钢消耗,既能提高炉包寿命,降低耐火材料吨钢成本,又能保证耐火材料产品不污染钢水,提高钢水纯净度,实现耐火材料企业和钢铁企业双赢。以太钢不锈钢冶炼耐火材料消耗占比较大工序AOD炉和钢包为例,对不锈钢冶炼用AOD炉和钢包冶炼环境进行了分析,对降低耐火材料单耗的方法进行了介绍。通过采用优质耐火材料原料改进材质、加强砌筑管理、优化生产节奏、采用在线热态喷补技术、提高透气砖寿命等,使不锈钢冶炼用耐火材料单耗和成本最低。

铸造起重机板钩轴改进

针对板钩轴定位卡板螺栓断裂导致卡板失位从平口槽中挤出,失去定位作用的问题,对板钩轴的结构进行了改进,通过采用有限元分析改进后的板钩轴强度及应力分布情况,确定解决卡板失位的有效措施是采用环形槽,这种结构形式的板钩轴既能起到轴向定位的作用,又能避免周向对卡板的冲击,从根本上解决了板钩轴窜动的问题,有效地消除了板钩脱落的安全隐患。

从连铸缺陷定量分析与改善到数智化应用设想

“双碳”背景下,对板坯热送率的要求越来越高,而无缺陷板坯是前提,因此对板坯裂纹缺陷进行分析,开发提升板坯质量的数智化工具势在必行。以宝山基地某铸机板坯为研究对象,采用统计方法与热力学计算从成分与组织角度进行了定量的裂纹缺陷分析与论证,发现不同影响因素的低缺陷发生指数控制范围,如调节主要合金元素使碳当量往非缺陷敏感区间移动,分别增加Mn、S比,Ti、N比超过阈值500、3.2,以及Al、N积(%×%)在含Ti与不含Ti时分别控制在低于阈值24×10^(-5)、8×10^(-5)。采用以上成分优化控制,同时保证铸机状态,热轧缺陷发生降低了75%。进而提出了改善裂纹缺陷的板坯连铸数智化应用设想,该应用通过智能连铸工艺参数设计、智能缺陷溯源、智能缺陷预测三大模块的开发,达到缺陷改善与热送提升,实现炼钢高效化、绿色化、智能化,为产品高端化保驾护航。

连续酸洗机组7.0~8.0 mm厚规格酸洗产品拓展实践

近年来应用户需要,某连续酸洗机组开展了屈服强度350 MPa以下、厚度7.0~8.0mm、宽度800~1300 mm酸洗板拓展试验.通过对现有设备能力负荷计算、开展取样离线样板焊接验证以及多轮通板生产验证,确定了该机组具备7.0~8.0 mm厚规格酸洗产品的生产能力.经过生产验证,该机组生产稳定,无异常问题,7.0~8.0mm厚规格酸洗产品质量达到用户要求.