宝钢不锈钢AOD炉侧吹工艺优化

通过对AOD炉冶炼不锈钢冶金过程进行动力学分析和数学模拟,阐述了AOD炉脱碳保铬过程的基本特征。根据AOD炉脱碳保铬时的临界碳含量,调整了宝钢不锈钢AOD炉的侧吹工艺,结果表明,AOD炉氧气利用率和铬元素收得率均有较为显著的改善。     

宝钢AOD炉冶炼不锈钢顶枪吹炼工艺分析

针对宝钢不锈钢分公司侧顶复吹AOD炉在实际使用过程中表现出来的脱碳速度偏慢、钢水中铬元素氧化量偏大、吹炼过程升温偏慢的情况,以实验室模拟研究结果为基础,通过将其顶部单孔氧枪改为三孔氧枪的方法,对比分析了AOD炉单孔顶枪、11°三孔顶枪和15°三孔顶枪在脱碳速度、钢水中铬氧化情况以及升温速度3个方面的各自表现.结果表明,当AOD炉以电炉提供的高碳母液为主原料时,在枪位设定合理的条件下,11°三孔顶枪的使用有利于进一步提高AOD炉脱碳速度、降低AOD炉钢中铬氧化并加快熔池升温速度;单孔氧枪由于孔数不足,其在AOD炉中的不锈钢冶炼效果不佳;15°三孔顶枪由于孔间夹角设定不合理,与宝钢不锈钢分公司AOD炉侧吹复合使用时效果不佳.     

宝钢不锈钢AOD转炉炉龄突破150炉大关

今年以来,宝钢不锈钢分公司炼钢厂AOD转炉炉龄不断取得新突破。5月份达到140炉,6月份达到了150炉,7月份一举突破了150炉,达到了152炉,创下了不锈钢分公司AOD转炉投产以来的新高,使不锈钢分公司AOD转炉炉龄跻身国内同行业先进水平。     

宝钢不锈钢分公司AOD炉龄实现“三级跳”

宝钢不锈钢分公司经过数年攻关,AOD炉龄实现了“三级跳”：2006年突破百炉,去年达到115炉,今年平均炉龄达到130炉。目前,AOD最高炉龄突破了170炉,比投产初期增加了近一倍,使冶炼工序成本大幅下降,有效作业率明显提升。     

宝钢不锈钢炼钢厂1号AOD炉副枪机器人技改通过验收

日前,宝钢不锈钢分公司炼钢厂1号AOD炉副枪机器人改造项目顺利通过相关部门验收。     

开发创新

太钢不锈热轧厂成功开发T91高附加值锅炉用钢，宝钢不锈钢分公司AOD转炉炉龄突破百炉.[编者按]     

对AOD炉和铬转炉炉渣冶炼行为的试验和计算研究

铬转炉和AOD炉通过氧化钢水中的硅和碳来生产不锈钢。为了延长铬转炉镁碳炉衬和AOD炉白云石炉衬的使用寿命，就必须减少炉子某些关键部位耐火材料的侵蚀（特别是铬转炉中的风口区域和AOD炉中的风口、耳轴区域），或在炉役期间采取措施保护这些部位。渣保护就是延长转炉炉衬寿命的一个选择方案。渣保护是在出钢后把转炉渣留在炉中，并使其在转炉炉衬的关键部位凝固的方法。在本研究中，铬转炉和AOD炉的渣保护与常用的碱性氧气转炉（BOF）的溅渣护炉不同，不采用溅渣，而是通过前后摇炉使熔渣涂敷在炉壁上的。     

宝钢3号高炉炉役后期稳产高产生产实践

针对宝钢3号高炉炉役后期设备老化、冷却壁破损、原燃料劣化等诸多不利因素,积极探索炉役后期的操作制度.通过加强原燃料管理、优化煤气流分布、控制休风率、加强设备管理等措施实现了高炉稳定高产,并通过加强炉身、炉缸长寿维护,确保了高炉长寿.     

基于炉体调查的宝钢3号高炉长寿经验

宝钢3号高炉停炉以后,对高炉的炉体侵蚀情况进行了系统的调查,结合调查结果,重点从高炉长寿设计、不同炉役时期的高炉操作和长寿维护等三个方面,阐述了3号高炉的长寿经验。认为3号高炉能够取得一代炉役寿命19年、单位炉容产铁量1.57万t/m~3的长寿业绩,一是高炉长寿设计,为长寿奠定了基础;二是高炉操作上保持长期的炉况稳定顺行,为长寿提供了重要保障;三是炉役后期加强高炉的长寿维护,为长寿起到了关键性作用。     

转炉+AOD两步法冶炼不锈钢物热平衡模型开发

以高炉铁水为主原料，利用合金熔化炉熔化高碳铬铁、镍铁等合金，采用转炉进行脱磷，再将混合后的不锈钢母液兑入AOD炉进行精炼脱碳来生产430、410及其他马氏体等常规400系不锈钢，这是近年来国内流行的两步法不锈钢生产工艺流程。基于宝钢德盛不锈钢有限公司两步法不锈钢工艺流程，建立转炉与AOD炉的物料平衡和热平衡计算模型，对转炉+AOD的两步法物料平衡和热平衡工艺、物料匹配工艺等方面进行系统优化研究，探索不同炉料组合生产常规400系不锈钢的工艺路径。研究结果表明，中频炉(合金熔化炉)的使用对AOD冶炼的热平衡有很大影响，当不使用中频炉时需要使用焦炭补充热量缺口，并以品种不锈钢废钢作为冷却剂来保证出钢温度满足生产要求；铬铁水在AOD入炉不锈钢母液中最优的配比为30.0%～32.5%,这时基本不需要额外加入焦炭和不锈钢废钢。模型计算结果可为转炉+AOD两步法生产不锈钢提供生产指导。     

提高45t AOD炉龄的工艺实践

通过采用镁钙砖取代镁铬砖作为太钢45 t AOD精炼炉的炉衬材料,制定合理的AOD炉衬烘烤制度,缩短精炼时间,控制炉渣碱度CaO/SiO₂=1.8~2.0,(CaO+MgO)/SiO₂=2.0~2.4,使45 t AOD炉龄由50炉次提高到189炉次。     

Fundamental Mathematical Model for AOD Process. Part II: Model validation

A fundamental mathematical model for AOD process has been developed and proposed in “Fundamental Mathematical Model for AOD Process. Part I: Derivation of the Model” 1 . Validation of the model with process data, measured from full scale AOD process, is presented in this paper. A broad selection of input data for the model was exported from various types of full scale industrial AOD heats. In this study 6 different types of heats were studied and simulated. Process data was measured from two AOD converters (95 t, 150 t). Validation of the model was then done by comparing simulated and measured values for carbon and chromium content, carbon release rate, melt composition, slag composition and bath temperature during final stages of carbon removal. The validation results showed that the model was in good agreement with the measured process data, and same model parameters were valid in all of the simulated heats.     

Improvement in prolonging AOD refractory lining life in Baosteel

A series of improvements in prolonging the AOD refractory lining life in Baosteel are introduced and analyzed in this paper,including modification of the AOD shell shape,adjustment of the top slag components and selection of the side-blowing tuyeres. Firstly,the layout of side-blow tuyeres was altered with the angle between each two tuyeres being 22.5° instead of the original 18°,and the connection of the outside steel shell in the side-blow area was modified from the former platform shape with great stress concentration into a new smooth circle shape. Secondly,the slag components were changed from the former CaO-FeO-SiO2 system to the CaO-MgO-SiO2 system. Besides,the basicity of the top slag was kept higher than 1.8,and the MgO content in the slag was kept within the range of 8%-12%. Finally,tuyeres with an inner diameter 13% smaller than that of the original tuyeres were used. Based on these research and optimization work,the thermodynamics and kinetics in the AOD refining bath has been improved markedly,and the campaign of the AOD has been prolonged from 45 heats at the beginning of its start-up to the current 185 heats. Meanwhile,the yield of chromium alloy and the decarburization efficiency have also been improved.     

冶炼不锈钢30 t EBT电弧炉炉衬寿命的提高

上海三钢公司特钢厂改进不锈钢初炼电弧炉操作工艺、造渣制度和采用炉渣发泡技术后 ,使初炼炉炉衬寿命从 3 0炉提高到 60炉以上 ,保证 2台EBT电弧炉与 1台AOD相匹配。     

提高410S不锈钢连浇炉数的工艺实践

邢钢一步法(脱磷站+60 t AOD+LF)生产410S不锈钢过程中,由于AOD的冶炼周期远大于连铸机浇钢和脱磷站的处理时间和连铸中间包水口下部侵蚀严重无法实现多炉连浇,严重影响连铸机作业率和整体钢铁料消耗。提高单中间包连浇炉数有利于减少中间包的使用数量、提高连铸机的作业率、降低钢铁料消耗、降低连铸机辅材及能源介质消耗。通过合理提高入炉冷态返回废钢比例(3.5t/炉),选择合适合金硅含量(3.5%)来缩短410S不锈钢AOD的冶炼周期至71 min,连铸机采用中间包分体水口快换,使连浇炉数由6炉提高到12炉。     

Mathematical modeling of the argon-oxygen decarburization refining process of stainless steel: Part II. Application of the model to industrial practice

The mathematical model proposed and presented in Part I of the present work has been used to deal with and analyze the austenitic stainless steel making (including ultralow-carbon steel) and has been tested on data of 32 heats obtained in producing 18Cr9Ni-grade steel in an 18-t argon-oxygen decarburization (AOD) vessel. The results indicated that the carbon concentrations and bath temperatures at the endpoints of blowing periods, calculated by the model, are in excellent agreement with the determined data, and the Cr content after the predeoxidization, obtained from the model predictions, also agrees very well with the observed value. The Gibbs free energies of the oxidation reactions of elements can be used to characterize fully the competitive oxidation among the elements during the refining process and to determine reasonably the corresponding distribution ratios of oxygen. The critical carbon concentration of decarburization (after which the decarburization changes to become controlled by the mass transfer of carbon in molten steel) for the AOD refining process of austenitic stainless steel in an 18-t AOD vessel is in the range of 0.25 to 0.40 mass pct. The model can provide some very useful information and a reliable basis for optimization of the technology of the AOD refining process of stainless steel and control of the process in real time and online.     

Mechanisms of dust generation in a stainless steelmaking converter

The four possible mechanisms of dust formation in converter steelmaking are evaporation of metal, ejection of slag, ejection of metal and entrainment of solids. In order to describe the relation between process operation and dust formation and take appropriate measures to minimize the quantity of dust, more detailed information is needed on the amounts contributed by the different dust generation mechanisms. For their determination, dust samples were taken from the off-gas during refining of five austenitic heats in a modified 80-t AOD converter. On the basis of dust, metal and slag analyses and process and product gas flow rates, the contributions of the different dust generation mechanisms were quantitatively determined for blowing step I (pure oxygen blowing) and reduction step R (pure argon blowing). The predominant mechanism is ejection of metal and slag droplets by bursting of bubbles at the bath surface. Dust formation via the vapour phase in AOD steelmaking is of less importance than previously expected, the relative amount is only about 3 %. During the addition of fluxes through the converter mouth, the entrainment of solids plays a role, too.     

合成镁白云石砂的研制与应用

选用优质轻烧白云石、轻烧菱镁石为原料,经干法消化、高温煅烧,制得杂质含量2.66％、体密>3.28g/cm~3的合成镁白云石砂。用合成镁白云石砂制得CaO MgO>97％,总杂质含量2.11％的高纯合成镁白云石砖,在太原钢铁公司AOD炉第一次试用,最高炉令达36炉次。     

K-OBM-S转炉冶炼不锈钢过程的数学模拟和应用

K-OBM-S转炉是以铁水和电弧炉预熔钢液为原料冶炼不锈钢的精炼设备。以转炉冶炼普碳钢的顶吹模型和AOD法冶炼不锈钢模型为基础,建立了适用于80 t K-OBM-S转炉冶炼不锈钢的数学模型。对二步法冶炼2Cr13型不锈钢和三步法冶炼0Cr18Ni9型不锈钢的过程验证结果表明,大部分终点碳含量的误差≤±0.03%,终点铬含量误差≤±0.3%,110炉0Cr18Ni9钢目标碳(0.10%～0.25%)命中率为95.6%,终点目标铬(17.1%17.6%)的命中率为85.2%。     

基于案例推理的AOD炉能耗诊断系统

采用基于案例诊断技术对AOD炉能耗进行诊断,以AOD炉物料平衡和能量平衡为基础,引入载能体的概念,建立AOD炉的能值模型,对铁水比、废钢比、AOD炉处理时间和两炉间隙时间对AOD炉能值的影响进行模拟,确定其对AOD炉能值影响的权重,结合层次分析法确定各个影响因素的权重,采用案例推理技术对AOD炉能值进行诊断。将AOD炉能耗诊断系统应用到某不锈钢公司AOD炉上,诊断AOD炉能耗上升的因素,为降低AOD炉能耗提供了决策依据。