内压缩流程──提高氧、氮产量的途径

本文通过计算，介绍了采用可逆式换热器带增压透平膨胀机工艺流程方案，拟改造从林德公司引进的２８０００ｍ～３／ｈ空分设备，提高氧、氮产量。     

宝钢5~#制氧机提产实践

宝钢制氧5#制氧机由于主塔设计较高,液氮进入上塔过冷度不够,而导入上塔的拉赫曼气较多,为防止粗氩塔氮塞,在操作中往往采用减少氧产量的方法来减少馏分氩中的氮含量,从而引起进入一级粗氩塔氩馏分中的含氧量较高,粗氩塔负荷增加,产品液氩量减少。研究了宝钢5#制氧机的膨胀空气量与上塔过冷度间的关系,通过一系列塔内工况的调整和优化,达到降低粗氩塔的负荷,增加氧、氮、氩产量的目的。     

提高钢中氧氮分析准确度方法的探讨

由于钢中氧氮对钢的性能和质量有明显影响,准确测定氧氮的含量对改进工艺控制、改善钢的性能、提高钢的质量具有重要意义。针对仪器法测定氧氮的分析过程,分析了各个环节可能产生的误差,对减少误差和提高准确度的方法进行了探讨。     

钢中氢、氮、氧的来源及其控制对策

比较了国内外钢中氢、氮、氧的水平 ,叙述了国外对纯净钢要求不断提高的过程 ,分析了钢中氢、氮、氧的来源 ,讨论了氢和氧的变化规律、吹氧过程中氮的变化以及碳和氧的关系 ,提出了减少钢污染的有效方法 ,总结出净化钢液的主要技术措施     

钢中氢,氮,氧的来源及其控制对策

本文比较了国内外钢中氢、氮、氧的水平，叙述了国外对纯净钢要求不断提高的过程。分析了钢中氢、氮、氧的来源，讨论了氢和氧的变化规律、吹氧过程中氮的变化以及碳和氧的关系。提出了减少钢污染的有效方法，总结出净化钢液的主要技术措施 。     

钢铁氧氮分析用内控样品的研制

为了降低检测成本,并提高氧氮分析结果的准确性,天钢通过基材筛选、样品加工、均匀性检验、分析定值等环节,研制出一种钢铁氧氮分析用内控样品。该样品可作为钢铁氧氮分析的质量控制样品,建立校准曲线,提高样品检测质量。钢铁氧氮内控样品在使用时与待分析试样同时进行试样加工,加工过程与待测样品完全一致,可以消除样品制备过程对分析结果的影响。     

高碳硬线钢洁净度控制及改进

为降低高碳硬线钢氮氧和夹杂物含量,提高拉拔成材率,实行了精炼、连铸过程控氮氧措施,措施实施后使线材成品全氧含量平均下降了9 ppm,氮含量下降7 ppm。夹杂物的级别和数量均有所减少,分布状态由聚集向弥散转变。     

提高钢中氧氮分析准确性的探讨

准确测定钢中氧氮数据对于生产冶炼具有很好的指导作用,主要通过对氧氮测定过程中可能存在的干扰因素进行分析,并寻找适宜的处理措施,提高钢中氧氮分析的准确性,减少不必要的质量事故。     

唐钢RH钢水洁净度分析与研究

采用金相统计、扫描电镜、电子探针以及氮氧分析等试验方法对采用RH精炼的SPHD钢在精炼和连铸 环节各阶段钢水（坯）夹杂物的含量、类型和成分以及全流程氮氧质量分数进行了分析,试验结果表明:降低和避免 RH精炼铝氧升温有利于提高钢水洁净度和可浇性,对RH钢水中的夹杂物进行改性、提高夹杂物上浮速度是提高 钢水可浇性的重要措施,降低中包耐材侵蚀、避免卷渣是提高钢材洁净度的重要保障。     

新钢11号高炉高富氧操作实践

对新钢11号高炉高富氧操作实践进行总结,分析提高鼓风富氧率后高炉产量、燃料比、料柱透气性指数变化。生产实践证明,高富氧后高炉产量显著提高,在炉腹煤气量指数基本不变的前提下,保证了高炉顺行,燃料比得到一定程度的降低。     

氩直流辉光等离子体钢液脱氮的研究

用25 kg真空感应炉对0.02%C钢液进行氩直流(DC)辉光等离子体条件的脱氮实验,研究了氩辉光等离子体对钢液脱氮动力学的影响。结果表明,氩辉光等离子体钢液脱氮速度和脱氮效果明显优于真空钢液脱氮,当钢液氧含量为180×10^-6,在氩辉光等离子体下钢液中氮含量可降至9×10^-6。氩辉光等离子体对钢液的脱氮效果体现在界面化学反应上,提供了加速脱氮反应的动力学条件。     

Cell survival at low oxygen tension and dose build-up in argon

Mammalian cells were exposed to 250 kVp X-irradiation in air, argon and nitrogen to determine whether cells irradiated when severely hypoxic have survival curves with lower extrapolation numbers (n) than their aerobic counterparts. Cells irradiated suspended in liquid showed no significant differences between values of 'n' irrespective of the gas used, neither was the sensitivity of cells irradiated in argon any greater than that of cells irradiated in nitrogen. In contrast, cells attached to glass dishes irradiated with the medium withdrawn were apparently much more sensitive in argon than in nitrogen. It has been demonstrated that the lower survival of cells irradiated in argon could have been caused by the greater photoelectric absorption in argon compared with nitrogen. When the dosimetric discrepancy was removed either by absorption of photoelectrons in liquid or by use of high energy radiations, there was no evidence that severe hypoxia during irradiation could lead to reduced values of 'n'.     

邢钢低碳400系铁素体不锈钢AOD控氮工艺实践

在低碳400系不锈钢中,氮能恶化晶间腐蚀、低温冲击韧性、缺口敏感性和焊接等性能。因此,在低耗、高效前提下降低其氮含量成为AOD冶炼中的重要课题。结合生产试验,通过探讨回归分析法在其吹氩脱氮工艺控制中的应用,结合脱氮的热力学计算对AOD生产实践数据的分析,由拟合方程确定的AOD冶炼410S不锈钢和低碳430不锈钢时氮氩切换点为吹氮450m³时切换氩气,410S不锈钢正常冶炼时一般吹氩量控制在1550m³,低碳430不锈钢AOD吹氩量一般控制在2050m³时可以将AOD终点氮含量控制在0.009 0%以下,并降低氩气消耗。     

Nitrogen Removal from Molten Steel under Argon DC Glow Plasma

Under argon DC glow plasma, the nitrogen removal from molten steel was studied. The experimental result showed that nitrogen mass percent could be reduced to 0. 000 8 %. The change of polarity had no impact on nitrogen removal when the nitrogen mass percent was low. The mechanism of denitrogenation of molten steel under argon DC glow plasma was discussed.     

Influence of surface nanostructure on the life of cermet in metal cutting

Nanostructuring of the surface layer of a cermet (titanium carbide + nickel alloy) by pulsed electron-beam treatment is studied experimentally. The nanostructural characteristics of the surface of the cermet after electron-beam treatment in gas-discharge plasma containing argon, argon + nitrogen, and xenon + nitrogen improve its frictional coefficient and correspondingly extend the working life of cermet plates in metal cutting.     

VD 真空吹氩脱氮模型

对Gaye真空吹氩脱氮模型进行了修正,并利用修正后的模型研究了真空度,吹氩量以及氧,硫含量等因素对VD真空吹氩脱氮效果的影响,结果表明,模型计算值与实测值符合较好,证明修正后的模型能够较好地模拟VD真空吹氩脱氮过程。     

510L汽车大梁钢LF精炼氮含量控制分析与应用

介绍了安钢第二炼轧厂采用铁水预处理→BOF→LF→CC的工艺路线生产510 L汽车大梁钢中的氮含量情况及LF精炼过程增氮的原因。结果表明,LF加热时间、埋弧效果、钢包底吹氩等操作是钢水增氮的主要原因。提出了LF精炼过程控制措施,通过合理控制加热时间、加强埋弧操作、稳定吹氩等措施,可控制氮含量≤50×10~(-6),满足510 L汽车大梁钢对氮的控制要求。     

Physicochemical grounds for the substitution of nitrogen for argon during out-of-furnace treatment of high-carbon steel

Physicochemical grounds for the possibility of replacing of argon with nitrogen during blowing a metal in the course of degassing and in a ladle-furnace unit are obtained using a mathematical model of degassing steel for out-of-furnace treatment. According to the data of examining the model for adequacy, the calculation error does not exceed 1%. A numerical experiment demonstrates that the replacement of argon with nitrogen during degassing of steel does not lead to any increase in the nitrogen content in it. Blowing in a ladle-furnace unit can be performed using an argon-nitrogen mixture taken in the proportion (2–3): 1. The replacement of argon with nitrogen allows the cost of the out-of-furnace treatment of steel to be decreased.     

100 t BOF-LF-RH-CC工艺冶炼结构钢时钢中氮的行为及控制

通过对淮钢100 t BOF-LF-RH-CC工艺流程冶炼45钢和42CrMo钢时各工序钢水取样分析氮含量,研究各工序对钢水中氮含量的影响。得出除吹氩和RH工序外,各工序都存在增氮现象:钢包至中间包长水口增氮占增氮总量的40%,LF精炼增氮占35%,出钢增氮占20%。所以控制转炉终点氮含量,控制LF渣层厚度,避免LF精炼补加合金和增碳,适当延长RH处理时间,提高长水口氩封效果是控制钢水氮含量的关键措施。     

精氩塔工况波动的原因分析与调整

介绍了粗氩塔和精氩塔的工况调整，分析了精氩塔内波动的原因，最终确认引起精氩塔波动的主要原因是液氮过冷度的影响，进行调整后，达到了稳定的工况。