ZYP40R塑料模具钢电渣重熔工艺实践

介绍了 ZYP40R模具钢的电渣重熔生产工艺.通过电极坯母材原始铝含量控制、电渣重熔时采用返回渣系、重熔过程脱氧剂分阶段加入、全程氩气保护等方式有效保证电渣钢中的铝含量,生产出符合要求的自耗电极及电渣锭.     

背面不充氩的不锈钢药芯焊丝ER308L-T的研制

在酸性渣系的基础上，通过添加少量氧化物，调整熔渣的流动性，并加入微量的强脱氧剂，以增强背面焊缝的保护，研制成功一种背面不充氩的不锈钢打底单面焊双面成形专用药芯焊丝。     

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通过采用新型脱氧工艺和优化精炼渣系方法进行了帘线钢生产的工业试验。实现了对帘线钢生产过程中夹杂物的塑性化控制。结果表明:夹杂物中的镁主要来源于钢包耐火材料;夹杂物中的铝主要来自于精炼过程中所加入的合金和脱氧剂。采用新型脱氧工艺,并将精炼渣碱度控制在适当的范围内,可以将夹杂物控制在塑性区域内。     

电渣重熔对钢的各向异性的改善

本文介绍了太原重型机器厂分别用碱性平炉法、碱性电炉法、电渣重熔法冶炼生产船用锻件和电站转子锻件的各向力学性能 ,并着重对电渣熔炼影响钢的各向共性系数的因数进行了分析     

电渣重熔体系内熔渣流场的数学模拟

建立了电渣重熔体系内电磁力作用下熔体流场的数学模型，并将其应用于在结晶器直径为２００ｍｍ的实验室装置上以ＣａＦ_２＋３０ｍａｓｓ％Ａｌ_２Ｏ_３＋２０ｍａｓｓ％ＣａＯ系熔渣进行的低碳低合金钢重熔过程（电极直径７６ｍｍ，３０００Ａ（ｒｍｓ））。合理选取模型参数值，计算了电磁力作用下体系内渣池的流场。结果表明，在电磁力作用下，渣池内形成沿结晶器壁向上，经熔渣自由表面和电极端部锥面又沿体系对称轴向下流动的两个旋涡，最大流速区约位于渣池内体系对称轴中部，涡心基本上位于半渣池中央略偏左、右下方的区域。对一些假想工况下的情形作了模拟，考察了重熔电流、填充比和电极端部形状对重熔体系内渣池流场的影响。与一些物理模拟结果作了比较。     

ACTIVITY OF TiO_2 IN MOLTEN BLAST FURNACE SLAG

Activity of TiO_2 in the molten blast furnace slag containing TiO_2 has been examinedat 1500℃ by means of “molten slag-Sn” chemical equilibrium method,using metallicSn as flux and graphite as deoxidizer,together with phase diagram caIculation.In thepentary slag system CaO-MgO-SiO_2-TiO_2-Al_2O_3,a_(TiO_2)=0.01—0.05 or 0.02—0.10 withpure liquid or solid TiO_2 as standard state,respectively.The activity and activitycoefficient of TiO_2 in relation to concentration of TiO_2 have been discussed.     

电渣熔铸异型件熔渣内溢现象

分析了异型电渣熔铸件生产过程中的熔渣内溢现象及形成因素.研究表明,更换电极中断功率操作后,供电工艺参数与结晶器冷却强度不匹配是导致结晶器内熔渣溢流的主要原因.从更换电极操作与熔铸工艺进行改进优化,改进后实际生产效果良好.     

高温镍基合金电渣重熔过程中的Al、Ti成分控制

电渣重熔过程中Al和Ti的氧化导致电渣锭轴向成分不均匀,从而对电渣锭的耐腐蚀性能和力学性能产生不利影响。为了控制电渣铸锭中Al和Ti含量的均匀性,需要明确高温电渣重熔过程中Al和Ti含量的变化,并通过优化渣体系比例和冶炼条件来减少合金中Al和Ti的氧化。在现有文献的基础上,以CaF₂-CaO-Al₂O₃-MgO-TiO₂这一低氟渣系和Incoloy825合金为例,综述了电渣重熔过程中Al和Ti元素控制的研究现状。应用离子与分子共存理论（IMCT）,结合FactSage软件,总结了渣的热力学和动力学研究方法。讨论了温度和渣成分对合金中平衡Al、Ti含量的影响。基于膜渗透理论,提出了预测合金中Al和Ti含量的动力学模型,得到了电渣过程中Al和Ti含量随时间变化的数学方程式以及渣-金属反应速率的限制方法。确定电渣重熔Incoloy825合金时TiO₂的最佳添加量约为10％。用IMCT和FactSage对渣-金平衡实验结果进行了比较和分析。FactSage计算结果比IMCT计算结果更准确。TiO₂含量越高,计算结果与实验结果之间的偏差越小。     

电渣熔铸渣池热电场有限元模拟的前置处理

对电渣熔铸渣池进行了热电场有限元模拟的前置处理,建立了电渣熔铸渣池热电场数学模型,定义了以自耗电极、渣壳、水冷结晶器、渣池为对象的计算区域.借助大型有限元软件ANSYS,对计算区域进行了合理的单元、插值函数选取以及网格划分,研究发现渣池存在两个区域:一是温度很高、电流密度很大且分布很不均匀的小区域,位于自耗电极端部附近,为高热源区,另一是电流密度小且分布几乎均匀的大区域,为低热源区.     

具有发展潜力的电渣冶金技术

为了提高铸锭质量,降低生产成本,电渣冶金涌现出许多新的技术,介绍了几种具有发展潜力的国内外电渣冶金新技术,包括弧渣重熔、洁净钢形核铸造、单极电渣快速重熔、双极电渣连铸、旋转电极重熔技术和液态金属电渣冶金技术。     

免喷涂涂层的感应重熔工艺

研究了自制免涂合金粉末对感应重熔方法的适应性,以及重熔工艺参数对重熔层组织状态的影响。结果表明：对于免喷涂合金粉末采用感应重熔工艺是完全可行的,随感应电流的增大,熔化时间缩短,而组织状态未发生明显的变化,重熔层组织致密,未发现未熔合及夹渣等冶金缺陷。     

电渣精炼去除铝中杂质铁(英文)

采用添加Na2B4O7的KCl-NaCl-Na3AlF6渣剂对浇注的工业纯铝自耗电极棒进行电渣精炼,以去除纯铝中的杂质铁,并改善其力学性能。结果表明:电渣精炼后纯铝中的铁含量随着Na2B4O7添加量和电渣重熔时间的增加而减少,在Na2B4O7添加量为9%和重熔时间为30min的情况下,铁含量从0.400%降低到0.184%。电渣精炼后,纯铝的弹性模量、屈服强度和抗拉强度得到改善,尤其是其延伸率提高了43%。铁含量降低的主要原因是电渣重熔过程中熔渣和铝液滴反应生成富铁相Fe2B。渣-液体系的反应热力学计算从理论上解释了Fe2B的生成。     

Factors influencing power consumption and power-saving measures in ESR process

Since the USA patent of electroslag remelting(ESR) metallurgy was held by P. K. Hopkins in 1940, the ESR technology has now entered a relatively mature stage after a 70-year history of development. At present, the annual capacity of ESR steels around the world is approximately 2 million tonnes. ESR metallurgy emerged in China in 1958. Since then, electroslag furnaces were gradually installed in Chinese special steel plants. At present, there are more than 200 electroslag remelting furnaces in the metallurgical workshops of these steel plants with an annual production capacity of about 500,000 tonnes of ingots and components made of about 200 varieties of steels, including high quality steels and superalloys. This ESR technology is used as a special remelting and refining method for producing high quality steels and superalloys. However, traditional ESR technology has the disadvantages of environmental pollution and extremely high specific power consumption. High power consumption restricts, to a certain degree, the competitiveness of ESR steels in the marketplace. The measures of power saving in ESR have been researched in recent years. In this paper, some factors influencing power consumption, such as filling ratio, slag system, slag amount, melting rate and furnace structure are reviewed, and several new ESR technologies for power saving are proposed.     

68t加氢反应器电渣锭质量问题分析

炉号13ESR032加氢反应器电渣锭在电渣重熔过程中出现炉口冒黄烟,渣变黑,渣由还原性变为氧化性。通过分析电渣锭质量问题产生原因,提出解决措施并实施生产改进。改进后的电渣锭成分合格,成功交货。     

Sulfur distribution in preparation of high titanium ferroalloy by thermite method with different CaO additions

Ferrotitanium is used as a deoxidizer and alloying agent during steelmaking process,which has a high demand for sulfur control.Sulfur was introduced from raw materials in the process of producing ferrotitanium by thermite method,where CaO was used as fluxing agent.At the same time,CaO has a great desulfurization capability.Effects of CaO addition on the distribution of sulfur in high titanium ferroalloy prepared by thermite method were studied in this work.The equilibrium diagram of Ti-AlFe-S system was calculated by FactSage 6.4 software package with FactPS and FTmisc database.The alloy and slag samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),X-ray fluorescence(XRF)and high-frequency infrared ray carbon sulfur analyzer.The result indicates that the sulfur in the alloy firstly exists in the form of liquid FeS,thereafter TiS(s)and eventually Ti_2 S(s)during cooling.The sulfur is mainly distributed in the alloy,and only a small amount of sulfur remains in the slag.Moreover,it is noted that the sulfur in the alloy does not distribute homogeneously,and it exists in the form of solid solution phase,(Ti,Al,Fe)S.S content in the slag,the sulfur capacity of the slag and the sulfur distribution ratio(L_S)all increase with the increment of CaO addition,while S content in alloys decreases.     

拉丝用高品质45钢盘条的开发

结合凌源钢铁股份有限公司现场设备,通过冶炼时采用无铝脱氧剂,LF精炼采用无铝造渣材料,连铸二冷区采用弱冷方式,轧钢斯太尔摩冷却线采用标准型冷却方式等工艺,开发生产了拉丝用45钢盘条,产品实物质量完全符合拉丝材要求,并对浸蚀后的金相试样横截面局部颜色变深现象进行了讨论分析。     

70Cr3Mo钢支承辊辊坯的生产试制

采用电渣重熔工艺生产试制了70Cr3Mo钢支承辊辊坯。产品检验结果表明,辊坯的化学成分、超声波探伤、高倍检验全部合格。     

Reformulation of time averaged Joule heating in presence of temperature fluctuations

Abstract

Strong temperature fluctuations might exist in non-isothermal turbulent flow. When a RANS approach is used for simulation it is necessary to time average all properties that are temperature dependant. Here we focus on the time average of the Joule heating released within the turbulent slag region of an electroslag remelting process (ESR). For that the average temperature dependant electric conductivity of the slag was expressed as a function of the time averaged temperature field and its standard deviation. The results using this new approach are compared with the results given by the classical approach using only the electric conductivity at the time averaged temperature. It will be shown that the temperature fluctuations decrease strongly the amount of electric current flowing directly to the mould, and increase the efficiency of the remelting process by 50%.     

自耗电极自动进给系统下的电渣熔铸工艺参数优化

采用正交试验法,优化出自耗电极自动进给系统下的电渣熔铸工艺参数.按该工艺参数,所获铸锭内外质量好,重熔效率高.文中认为:工作电流和渣量是主要的控制因素,冷却水量是次要因素.     

超低氢高韧性无缝药芯焊丝TME711NiSF的研制

通过选择钛碱性渣系和Mn-Si-Ni-Ti-B合金系,在德国进口无缝药芯焊丝生产线上,制成了一种超低氢高韧性的无缝药芯焊丝TME711NiSF. 其焊接工艺性能和力学性能优良,对焊接热输入具有良好的适应性. 为探讨熔敷金属的韧化机理,对配方中的脱氧剂和合金剂含量进行了优化设计. 结果表明,Mn和Si元素含量居于优化水平时,焊缝组织主要是均匀细小的针状铁素体,这种组织的塑性和低温韧性高,熔敷金属在温度-40 ℃冲击吸收功可达到154 J. 该无缝药芯焊丝熔敷金属的扩散氢含量为2.4 mL/100 g,达到了超低氢水平,适用于船舶、桥梁、海洋工程等重要结构的焊接.