提高钢包自开率的生产实践

分析全程加盖条件下影响钢包自开率的主要原因,有针对性地对钢包下台倒渣、上水口和座砖清扫、加砂操作等制定了新的作业标准和规范,同时调整了引流砂的成分和粒度,使钢包在全程加盖后的自开率由93.68%提高至98.16%,不仅减少了因钢包引流操作造成的钢水污染,提高了钢水洁净度,还防止了因引流不开而导致的生产中断现象发生,确保了生产顺行。     

影响钢包自开率的因素分析及改进措施

为提高钢包自开率,分析了引流砂质量、出钢温度、钢水在钢包内停留时间和热修操作对钢包自开率的影响。结果表明,通过调整引流砂的成分配比及粒度分布,严格将水分含量控制在0. 2%以下,出钢温度在1 580～1 620℃、钢水在钢包内停留时间在90 min以内,并进一步加强钢包的日常管理,可使钢包自开率稳定控制在98%以上。     

提高连铸高铝钢钢包自开率的工艺研究

研究影响连铸高铝钢20Mn23AlV钢包自开率的主要因素,并结合宝钢特钢炼钢厂40 t钢包的实际情况,通过采取改进引流砂材质、全面烘烤引流砂、固化引流砂加入量、清理钢包水口以及优化精炼过程中底氩翻动效果等措施,最终解决了高铝钢因长时间受钢而造成钢包自开率低下的问题。     

钢包引流砂机械式投放技术的开发应用

针对莱芜钢铁集团有限公司银山型钢有限公司炼钢厂采用人工投放钢包引流砂,导致引流砂大量浪费,增加钢水夹杂,影响水口自开率,制约炼钢生产等问题,通过开发引流砂复合引流器投放工艺技术以及对钢包水口座砖内径进行调整优化等措施,实现了钢包引流砂机械式投放。使水口自开率由95.5%提高到99.2%,吨钢引流砂消耗降低了0.37 kg。     

提高重轨钢钢包水口自开率的生产实践

为了解决邯钢大方坯连铸机浇铸重轨钢钢包滑动水口自开率低的问题,分析了引流砂质量、水口尺寸、钢水在钢包内的停留时间,引流砂加入方式和水口清理等因素对浇铸重轨钢自动开浇率的影响。针对存在的问题提出了解决措施,包括研制新配方引流砂、研制新型水口、合理缩短精炼时间、改善钢包清理状态及规范引流砂加入方式等,使浇铸重轨钢的自动开浇率提高到97%以上。     

提高90 t 钢包水口自开率的措施

莱钢炼钢厂通过对90 t钢包水口自开率影响因素进行系统研究分析,采取铬质引流砂的合理选用、改进水口座砖、调整铬质引流砂的加入方式、改进现场存放制度、推行标准化装包作业、固定连铸机液压缸丝头、研究应用钢包红净出钢技术等措施,使钢包水口自开率由86%提高到95%以上,解决了转炉优钢全精炼条件下90 t钢包水口自开率低的问题,提升了转炉优钢质量,保障了生产顺行,降低了环境污染。     

钢包自开率影响因素分析及改进

分析研究了影响钢包自开率的主要因素是引流砂的选择。唐钢第一钢轧厂通过采取有效措施，钢包平均自开率由98％提高到98．7％以上，取得很好的经济效益。     

提高钢包自开率的措施分析

对影响钢包自开率的因素进行数据调查,通过采取使用高铬质引流砂、减少钢包渣结壳、足量加入覆盖剂、钢包下包零等待、连铸钢包全程加盖、钢包渣倒净、规范引流砂加入操作等措施,钢包自开率由88.25%提高至98.4%,有效的保证了生产稳定顺行和产品质量提高。     

钢包引流砂烧结与钢包自动开浇率提升研究进展

为了提升钢包自动开浇率,总结了钢包引流砂烧结的研究与工业实践成果,阐述了引流砂的烧结性能、钢包自动开浇的影响因素及提升措施,重点关注了不同材质引流砂的烧结机理和钢液对引流砂烧结的作用机制.不同材质引流砂的烧结结构类似,一般分为烧结层(包括部分烧结层)和未烧结层.引流砂的实际烧结层很薄,而且绝大多数引流砂会呈现未烧结的状...     

连铸钢包自开率的影响因素及改进措施

分析了工艺路线、冶炼钢种、引流砂添加剂、包内残钢残渣、水口座砖与包底的相对位置、合金加入位置、钢包类型等对钢包自开率的影响,并提出了相应的改进措施,使钢包综合自开率稳定在99.00%以上。     

影响抗酸管线钢钢包自开率因素的分析和改进工艺实践

抗酸管线钢API X65（/%:≤0.045C,0.15~0.35Si,1.50~1.65Mn,≤0.008P,≤0.001 2S,0.02~0.06Alt,0.45~0.65Nb,0.01~0.025Ti）由脱硫铁水-100 t顶底复吹转炉-LF-RH-板坯CC流程冶炼。分析了引流砂质量（石墨含量0.22%~0.86%）,钢包钢水停留时间（<180~>270 min）,LF精炼温度（<1620~1690℃）出钢口垂直度,钢包上水口寿命（2~28次）对自开率影响。结果表明,引流砂中石墨含量低,钢包钢水停留时间长,LF精炼温度高,出钢口和钢流偏移,钢包上水口使用次数少,则钢包自开率低。通过稳定相关工艺因素,控制引流砂中石墨含量≥0.8%,LF钢水停留时间180~240 min,LF终点温度≤1 640℃等工艺参数,使抗酸钢的钢包自开率由84.52%提高到97.47%。     

Effect of Chromite-Silica Sands Characteristics on Performance of Ladle Filler Sands for Continuous Casting

 Free opening rate is mainly determined by the performance of the ladle filler sand. High free opening rates of ladles are required in steel making to improve steel quality. Chromite ladle filler sands are one of the most widely used ladle filler sand. Several operative variables and materials characteristics affect the performance of the sands. Three sets of chromite ladle filler sands were selected and researches were focused on the sintering behaviour and performance of the sands under operative conditions. The effect of particle size distribution on sintering, microstructure, flowability, and permeability were presented. In all cases, the particle size varies from 01 to 15 mm corresponding to free flowing powders. One of the samples has higher permeability factor in comparison with others due to low particle size distribution. The other sample presents very good free opening due to its very good flowability and permeability factor.     

Process for improving the ladle free-opening rate for high aluminum steel in continuous casting

Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1. 6% to 2. 45%,which is significantly higher than other types of steel.According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company,previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are: sand material,accessories baking,ladle nozzle cleaning,the process and amount of adding sand,and the rate of argon stirring during refining. Therefore,improving the ladle filler sand quality,baking all of the raw materials,controlling the addition of ladle filler sand,cleaning the ladle nozzle,and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.     

42CrMo钢大尺寸夹杂物的来源与控制

针对42CrMo合结钢轧材超声波探伤合格率低的问题,利用扫描电镜等设备对探伤不合样品进行分析,发现探伤不合样品中有直径为100 μm左右的球形夹杂物或者尺寸为1 000 μm左右的长条形夹杂物。通过钢液内生夹杂和生产过程接触的原辅料的分析比对,认为大尺寸夹杂物主要由于外来夹杂进入钢液中,最终造成轧材探伤合格率低。通过增加硅钙线用量、钢包浇铸后期不下渣、浸入式水口侵蚀速率小于1.5 mm/h、结晶器液位波动不大于 ± 3 mm和恒定拉速浇铸等控制方式,减少了钢中外来大尺寸夹杂,提高了钢液洁净度,使探伤合格率提高到97.5%以上。     

氧化铝对铬质引流砂烧结行为的影响

为了揭示氧化铝颗粒在常规铬质引流砂烧结过程中的作用,通过实验室试验研究了不同氧化铝含量对引流砂烧结行为的影响。研究发现,在有无钢液作用下,氧化铝颗粒对常规铬质引流砂烧结的影响趋势基本一致。当添加的质量分数较少时(如不大于5%),氧化铝颗粒不仅不能起到抑制烧结的作用,反而有利于引流砂烧结;当添加质量分数超过一定值后(如不小于10%),氧化铝才有抑制烧结的作用。在常规铝镇静钢生产中,常规铬质引流砂可以获得很好的使用效果,因而不建议在铬质引流砂中额外添加氧化铝颗粒。钢液会显著加速引流砂的烧结,采用氧化铝来抑制高锰高铝钢对引流砂的作用切实可行,但需要足够高的氧化铝含量才能达到效果,后续还有待进一步研究。     

Thermodynamic analysis of steel deoxidization processes during tapping and refining operations

A thermodynamic model based on the interaction parameter approach for molten metal solutions and a quasi‐chemical model for molten slags and non‐metallic inclusions was employed to analyze steel deoxidization during tapping and refining operations in a ladle furnace. This model is able to predict the mineralogical nature of non‐metallic inclusions and their amount through thermodynamics and mass balances. It was found that the addition sequence of deoxidizers during a tapping procedure influences the nature and amount of the different inclusions. Besides, the metal‐slag equilibrium is readily reached after tapping and at the end of steel treatment in the ladle furnace. The model proved to be useful for steel cleanliness assessments and the design of steel deoxidization practices.     

氧化铝对铬质引流砂烧结行为的影响

为了揭示氧化铝颗粒在常规铬质引流砂烧结过程中的作用,通过实验室试验研究了不同氧化铝含量对引流砂烧结行为的影响。研究发现,在有无钢液作用下,氧化铝颗粒对常规铬质引流砂烧结的影响趋势基本一致。当添加的质量分数较少时(如不大于5%),氧化铝颗粒不仅不能起到抑制烧结的作用,反而有利于引流砂烧结;当添加质量分数超过一定值后(如不小于10%),氧化铝才有抑制烧结的作用。在常规铝镇静钢生产中,常规铬质引流砂可以获得很好的使用效果,因而不建议在铬质引流砂中额外添加氧化铝颗粒。钢液会显著加速引流砂的烧结,采用氧化铝来抑制高锰高铝钢对引流砂的作用切实可行,但需要足够高的氧化铝含量才能达到效果,后续还有待进一步研究。     

Analysis of source of macro- inclusions in bloom of bearing steel

In order to improve the steel cleanliness and remove macro- inclusions as many as possible, slime method was applied to study the types of the macro- inclusions in bearing steel at the steel company. The sources of these macro- inclusions were discussed based on the examination results of ladle filler sands. It is found that the amount of macro- inclusions at the initial casting stage of each heat is larger than that at the middle casting stage, while the types of the inclusions are very similar at both stages. Five types of macro- inclusions are detected in bloom. Calcium aluminate macro- inclusions are from the inclusions in liquid steel, while ladle filler sands are confirmed as the source of alumina, spinel and calcia macro- inclusions. Besides, even containing a trace of K, the TiO2- SiO2- FeO- CaO- Al2O3 system complex oxides are not originated from mold flux, but probably from the ladle filler sands and their sintering products. Some necessary considerations on secondary refining and continuous casting are needed to reduce the amount of macro- inclusions. Especially, ladle filler sands should be removed as many as possible before the casting of each heat.     

RH精炼过程中吹氧量对IF钢洁净度的影响

无间隙原子钢（IF钢）主要用于汽车、家电等行业,除需要极低的C、N含量外,对最终产品的表面质量也有严格要求。钢中O含量和夹杂物对产品的表面质量影响很大。快速降低钢中C含量、同时保证钢的高洁净度是非常重要的。为此,通过在Ruhrstahl Hereaeus（RH）精炼?连铸过程密集取样,采用ASPEX扫描电镜详细研究了RH吹氧强制脱碳工艺下吹氧量对IF钢洁净度的影响。结果表明,本实验条件下,吹氧量对精炼?连铸过程中夹杂物的类型和形貌没有影响。吹氧量对RH精炼前期（加Al后4 min内）钢液洁净度影响较大,而对后期生产过程中钢液的洁净度影响不大;精炼前期,吹氧量高,钢液中总氧（T.O）含量和夹杂物的量增加。簇群状夹杂物主要出现在RH破空之前,真空精炼结束后钢液中很难发现簇群状夹杂物。中间包钢液洁净度与RH吹氧量相关性不大,而与加Al脱氧前钢液中O含量相关性很大,加Al脱氧前钢液中O含量高,中间包钢液洁净度差;为提高中间包钢液的洁净度,应尽量减少加Al脱氧前钢液中的O含量。随着生产的进行,钢液中T.O含量、夹杂物的量呈下降趋势,洁净度逐渐提高。      

RH强制脱碳与自然脱碳工艺生产IF钢精炼效果分析

西昌钢钒厂由于转炉热量不足而以转炉—LF精炼—RH精炼—连铸工艺生产IF钢,为探究RH强制脱碳与自然脱碳工艺生产IF钢精炼效果,采用生产数据统计、氧氮分析、夹杂物自动扫描、扫描电镜和能谱分析等手段,对不同脱碳工艺对顶渣氧化性以及钢的洁净度影响进行了详细研究。结果表明:（1）与自然脱碳工艺炉次相比,采用强制脱碳工艺的炉次在转炉结束与RH进站钢中的平均[O]含量更低;（2）两种工艺脱碳结束钢中的[O]含量基本在同一水平;（3）强制脱碳工艺的炉次在RH结束时渣中平均T.Fe的质量分数降低了1.3%。在能满足RH脱碳效果的前提下,尽量提高转炉终点钢液碳含量、降低钢液氧含量,后续在RH精炼时采用强制吹氧脱碳工艺,适当增大吹氧量来弥补钢中氧,可显著降低IF钢顶渣氧化性。自然脱碳工艺与强制脱碳工艺控制热轧板T.O含量均比较理想;与自然脱碳工艺相比,强制脱碳工艺可有效降低IF钢[N]含量,这与强制脱碳工艺真空室内碳氧反应更剧烈所导致的CO气泡更多和气液反应面积更大有关。脱碳工艺对IF钢热轧板中夹杂物类型、尺寸及数量没有明显影响,夹杂物主要由Al₂O₃夹杂、Al₂O₃–TiO_x夹杂与其他类夹杂物组成,以夹杂物的等效圆直径表示夹杂物尺寸,以上三类夹杂物平均尺寸分别为4.5、4.4和6.5 μm,且钢中尺寸在8 μm以下的夹杂物数量占比高于75%。在RH精炼过程中,尽量降低RH脱碳结束钢中[O]含量,有利于提高钢液洁净度。