Iron is produced by the reduction of iron ore and other iron oxides as a precursor to steel and by remelting of metallic stock to produce a family of iron-based alloys (cast irons) for industrial use. More than 1 billion metric tons of iron is produced annually by reduction processes.1 Blast furnaces account for more than 90% of iron reduction with the rest accomplished through direct reduction or "alternate ironmaking" processes. Cupola furnaces, rotary furnaces, and induction furnaces are the primary units for cast iron re-melting. In 2009, the cast iron production of the main industrialized countries was 58.6 million metric tons. The role of oxygen combustion in reduction processes is described in Sections 21.2 and 21.3, and in re-melting processes in Section 21.4.

关键词：铁矿石；氧化铁；钢铁

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Directly-generated compressive residual stress has become a widely used surface modification technique. Intentional residual stress in solid materials can be produced by different surface compression methods. It is well known how residual stress field is influenced by the parameters of the shoot peening but only few articles address the phenomenon about the evolution of the stress during the operation of the machine component. The literature on residual stress decrease caused by fatigue load is scarce and the kinetics of this mechanism is not yet investigated. The present work reports on the examination of the effect of the fatigue load on compressive residual stress strengthened specimens. Investigations have been conducted at three stress levels. Residual stress data have been measured by X ray diffraction method before fatigue load and measurements have been repeated after defined fatigue cycles.

关键词：残余应力；X射线衍射；疲劳

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Small batches of two oxide powders falling in the particle size range of about 30-230 μm were received from industrial sources and were electroless nickel (EN) coated in order to prepare properly modified reinforcing particles for further laboratory experiments with the Laser Melt Injection (LMI) technique to produce particle reinforced steel composite surface layers. The partially calcined alumina (Al2O3) as well as the hydrothermally recycled crystalline iron(Ⅲ) oxide precipitate were characterized first to check their exact size ranges, specific surface areas and major chemical contaminants so that the best possible EN plating technique would be selected and applied. It was revealed soon that the sensitization and activation pre-treatment steps could not be omitted and after their proper adjustment, also the composition and pH of a relatively commonly used hypophosphite reducing type bath had to be modified to the given purpose. Eventually a slightly alkaline EN bath was successfully prepared with which both industrial oxide powders surface could be nickel coated soundly, which final result was demonstrated also by several metallographic testing techniques showing the microstructure of the quite evenly and fully coated oxide particles.

关键词：化学镀镍；氧化铝粉；氧化铁粉末

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The paper is focused on issues related to the behavior of reinforced soil walls at working stress and near failure, and the prediction accuracy of internal stability working stress and limit equilibrium (LE) design methods. The paper identifies the key variables, principles and assumptions that affect the accuracy of these methods considering the full range of conditions from working stress to failure. The strain at peak strength of a granular soil wall backfill is identified as a key parameter for understanding the differences between working stress and LE design methods. Both geosynthetic and steel reinforced wall systems are examined using measured reinforcement strain and loads taken from full-scale walls under both working stress (operational) conditions and at incipient collapse (failure).

关键词：工作压力；加筋土墙；钢铁

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Until recently, solvent-based forms of monomeric alkyl (isobutyl) trialkoxy silane, produced under various trade names, were exclusively used in the United Kingdom for concrete protection of transportation structures and other structures subject to surface salt contamination. Reflecting the move toward more sustainable construction and with increasing demand for less-hazardous materials, alternative protective treatments that are based on various aqueous formulations have emerged. These treatments include dual-purpose materials for protection and concrete coloration. At the same time, developments in nano-materials have resulted in the availability of a low-hazard pure silane that is neither water nor solvent based. This investigation evaluated the performance of this material and three water-based materials with respect to their resistance to water and salt solution absorption and chloride ion penetration. A comparative investigation assessed the possibility of using convenient concrete cubes rather than larger-scale slabs for chloride contamination testing by the salt-ponding method. The results of the study are particularly relevant to older reinforced concrete structures, which frequently suffer low concrete cover to their steel-reinforcing bars.

关键词：纳米；建筑；耐水性

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To predict phase equilibria of advanced high strength steels accurately,a new multicomponent thermodynamic database (FEDA) encompassing Fe,C,Mn,Si,Al and Ni is created according to relevant literatures.This study applies Thermo-Calc software to estimate phase transformation temperatures and phase fractions in ferrite and austenite two-phase region of test steels.Simultaneously,experiments are carried out with dilatometer and the quantitative metallographic analysis technology.It is found that the FEDA database is appropriate for predicting A/temperature and phase fractions of Al-containing steels at low temperatures,while the TCFE6 database can be used to estimate A3 temperature.According to calculated phase fractions using FEDA database,a two-step heat treatment is made in order to achieve TRIP-aided steels.Samples annealed at 780℃ for 3 min and held at 420℃ for 5 min exhibit an optimum value of strength and ductility product up to 23690 MPa.％.

关键词：热力学参数；含Al的AHSS；相馏分；转变温度

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On the base of the analysis of the electricity production and consumption characteristics of iron and steel enterprises,this paper has established a optimization model of electricity production in iron and steel enterprises which comprehensive considered the electricity,gas,and steam.It can do joint optimization scheduling from electricity production and outsourcing,gas distribution,and steam production three sides,so that it can provide a reasonable electricity production and outsourcing strategy for iron and steel enterprises to reduce the system operation costs.Where,the optimized allocation of surplus gas and steam production scheduling is the means,the optimization scheduling of electricity production and outsourcing is ultimate goal.

关键词：节能；钢铁企业；电力；优化

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常规的国家标准方法(EDTA滴定法或分光光度法)不满足铝质量分数小于0.01%的不锈钢分析要求。试验通过新建铝元素虚拟分析通道,重建虚拟通道的分析曲线,消除不锈钢中含量较高的共存元素对于铝元素测定的干扰,利用原通道和虚拟通道分离铝元素的分析范围,使用高低标法对低含量段铝进行校正,提高了火花源原子发射光谱仪对于不锈钢中痕量铝元素的分析准确度。试验证明:上述改进对于光谱测定不锈钢中痕量铝含量的准确度有明显的提升;在不锈钢中铝质量分数小于0.001%的情况下,该方法的测定误差可以控制在0.000 5%以内且分析精密度与电感耦合等离子体原子发射光谱法(ICP-AES)的精密度相近;经统计分析,铝元素分析曲线校正后12h内不易发生漂移;生产样均匀性能够满足分析要求。因此实验方法能够满足不锈钢生产试样炉前快速分析的需要。

关键词：火花源原子发射光谱法；不锈钢；痕量铝；虚拟分析通道

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样品均匀性和稳定性评价是能力验证活动的重要组成部分。依据CNAS—GL03《能力验证样品均匀性和稳定性评价指南》,介绍了能力验证样品均匀性和稳定性评价的基本原理。以食用油中丁基羟茴香醚(BHA)的均匀性检验和茶叶中铜稳定性检验为例,简述了EXCEL"数据分析"工具应用于能力验证中样品均匀性和稳定性评价的使用方法,实现了实验数据的输入,得到数理统计的F值和t值。从结果可以看出:EXCEL数据处理结果与实例的计算结果是相一致的,即通过EXCEL的"数据分析"可以完成能力验证中样品均匀性和稳定性检验的工作,从而提高工作效率和统计结果的准确性。

关键词：能力验证；均匀性；稳定性；EXCEL

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采用偏光显微镜法测定了某未知工业矿物粉体样品中的微量石棉纤维。样品通过450℃高温热处理及酸洗过程去除大部分干扰物质,经乙醇分散后均匀沉积在玻璃片上,滴加具有固定折射率的浸渍液制成试片。在正交偏光系统下观察到粉体中存在纤维状颗粒,且纤维呈现四次平行消光特性,干涉色为白色,即具有中等折射率,插入石膏试板后根据纤维在不同象限的颜色判定其具有正延性。单偏光系统下纤维无多色性现象。在离散染色系统下经尝试不同折射率的浸渍液,观察可知纤维的折射率接近1.618 0。综合所有光学性质分析可测定样品中含有少量的透闪石石棉纤维,同时可估算出该种石棉纤维的质量分数约为1%。

关键词：石棉；透闪石；偏光显微镜；工业矿物粉料

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