由矿石带入的痕量元素对钢力学性能的影响

对８个钢厂，３个钢种的５２０炉钢的力学性能，化学成分，组织特征等共１６０００多个数据，进行相关分析；在聚类分析，主成分分析，因子分析，逐步回归分析的基础上，建立了１２个回归方程，讨论了钢中５个常规元素及由矿石带来的痕量元素对钢力学性能的影响。     

关注钢材期货

前期天量铁矿石的进固，制造中国需求繁荣表相，掩盖中国钢铁业对铁矿石的真实需求，对铁矿石谈判造成不利影响。有机构认为，支持钢价上涨的因素有：市场资金充裕；原料价格上涨导致成本支撑；钢厂战厂价上调推动市场价格上涨。     

限电限产 钢材量减价涨

钢价探底回升，库存、产量双降六七月份我国钢材价格大幅回落后，铁矿石、焦炭等原料成本降幅较小，部分钢铁企业出现亏损，大钢厂集中检修，中小钢厂关停高炉等设备，全国钢铁产量高位回落，库存量出现下降，钢材市场供过于求压力减轻。     

载体分馏光谱法测定镍基高温合金中痕量杂质元素Pb、Bi、Ag、Tl

载体分馏光谱法测定镍基高温合金中痕量杂质元素Ｐｂ、Ｂｉ、Ａｇ、Ｔｌ李德新，杜祖晓，孙景义，傅文周（辽宁抚顺钢厂中心试验室，抚顺，１１３００１）本文应用载体分馏光谱法，可不经化学分离，而直接、快速、简便地测定镍基高温合金中痕量杂质元素Ｐｂ、Ｂｉ、Ａｇ、...     

直读光谱仪测定纯净钢中痕量元素铌钒硼含量

运用ARL-4460型直读光谱仪对纯净钢中痕量元素Nb、V、B的测定进行了研究,通过对分析条件、样品制备条件、工作曲线的建立及校正等试验,建立了直读光谱测定纯净钢中痕量元素Nb、V、B方法,该方法的测量结果准确度高、精密度好,能够完全满足生产工艺要求。     

熔融法制样X射线荧光光谱法检测铁矿石中锡元素含量

钢中的锡可降低钢及合金的高温机械性能，对钢的加工性能也十分有害。在钢中加入少量锡能提高钢的耐腐蚀性，强度也有一定提高，而对塑性却影响不大。为满足特钢冶炼及高炉长寿需求，检测项目需对铁矿石锡元素的含量进行检测。铁矿中锡含量检测目前采用火焰原子吸收法或原子荧光光谱法。这两个方法，虽然结果准确可靠，但样品处理流程繁琐，耗时费力，且人为可干扰因素较多。X射线荧光光谱分析，具有分析精度好、准确度高和检测速度快等优点，已广泛应用于铁矿石的常量和微量元素检测。文章用1个原脉锡矿标样、15个原脉锡矿标样和高纯三氧化二铁配制成的合成样，共16个样品，试验确定X射线荧光仪检测铁矿石中锡的分析条件；在用帕纳科Axios MAX型X射线荧光光谱仪测铁矿石方法上建立能同时测定铁矿石中锡含量的快速检测方法。对铁矿样品进行精密度考察，锡的相对标准偏差(RSD,n=11)为3.47%;采用实验方法对铁矿石中锡进行测定，所得结果与其他方法有较好的一致性；用MSA对方法的测量能力评定，测量能力为可接受，满足日常分析要求。     

铁矿石短缺成为我国钢铁工业发展的一大挑战

我国铁矿石品位低下，且可采储量、年限均偏低，导致国内钢厂增加白海外进口铁矿，以满足生产需求。对此，中国工程院认为，铁矿石的限制因素将是21世纪中国钢铁工业发展面临的一大挑战，而在炼钢原物料供应持续吃紧的背景下，建议钢铁工业应以人均消费钢160-180kg／a的最低值，完成工业化进程。     

包钢、唐钢捆绑海外矿山稳定原料供应

随着新年度铁矿石谈判的临近，不愿受制于三大铁矿石供应商的国内大钢厂更加大海外找矿的力度。昨天，《第一财经日报》获悉，包钢和唐钢都与海外矿山企业签署协议，以稳定自身的资源供应。     

低密度钼铁在钢液中溶解效果好

钢厂使用高熔点铁合金例如钨铁、钒铁和钼铁作为合金添加剂，往往会产生许多问题，这些合金在钢液中的溶解性不好，因而导致合金元素在钢中具有很大的不均匀性。     

浅谈含钒铁水预处理工艺实践

为了提高钢材质量，满足用户对钢产品的苛刻要求，国内外主要钢厂纷纷开发铁水预处理工艺，以进行脱硫、脱磷及脱硅处理。随着工艺技术的不断进步，如今铁水预处理的概念己发生了变化，预处理有两个作用：一是将钢中有害元素如S、P在进入炼钢工序前最大限度地去除，     

CHARACTERIZATION OF PROPERTIES AND REDUCTION BEHAVIOR OF IRON ORES FOR APPLICATION IN SPONGE IRONMAKING

Studies on the chemical and physical properties, and the reduction behavior (in coal) of hematite iron ores procured from 10 different mines of Orissa, were undertaken to provide information for the iron and steel industries (sponge iron plants in particular). The majority of the iron ores were found to have high iron and low alumina and silica contents. All these iron ores were free from the deleterious elements (S, P, As, Pb, alkalies, etc.). The results indicated lower values of shatter and abrasion indices, and higher values of tumbler index in all the iron ore lumps except Serazuddin (previous) and Khanda Bandha OMC Ltd. For all the fired iron ore pellets, the degree of reduction in coal was more intense in the first 30 min, after which it became small. Slow heating led to higher degree of reduction in fired pellets than rapid heating. All the iron ores exhibited more than a 90% reduction in their fired pellets in 2-h time interval at a temperature of 900°C. Iron ore lumps showed a lower degree of reduction than the corresponding fired pellets.     

高炉配加经济矿料生产实践

经济矿料通常由褐铁矿或半褐铁矿组成,含铁品位低、杂质多,在烧结中配加它是钢铁行业应对资源危机、降低生产成本的有效措施之一。安钢通过生产试验与理论探索,烧结经济矿料的使用量占到了铁矿粉消耗总量的50.1%,成本下降10%左右,完全适应了大配比经济矿料烧结生产。同时,高炉操作为适应低品位经济矿料采取了各种措施,实现了较好的技术经济指标。     

Effect of the presence of alloying elements in interstitial-free and low-carbon steels on their surface composition after annealing in reducing atmospheres (dew point=−30 °C)

The X-ray photoelectron spectroscopy (XPS) method is used to study the outer surfaces of interstitial-free (IF) and low-carbon (LC) steels with different alloying element contents (P, Ti, Nb, and Mn) after annealing at temperatures of 805 °C and 705 °C, respectively, for 40 seconds in reducing atmospheres (dew point=−30 °C). The work discussed seeks to establish possible relationships between the bulk composition of the IF and LC steels and the contents of segregated alloying element observed by XPS on the surface of the annealed steels, as well as to establish the influence of the presence of a thin iron oxide film on the steel surface on the segregation and oxidation of the alloying elements. Despite the low Mn and Si bulk steel contents and the shortness of the annealing cycle, considerable enrichment of these elements on the surface is seen, mainly as manganese and silicon oxides. The formation of a MnO layer on the annealed steel surface seems to be related to the reduction of iron oxides and the increase in the metallic Fe content. Despite its low content in LC steels, carbon also seems to diffuse towards the annealed steel surface to reduce iron oxides.     

澳大利亚铁矿粉的烧结基础特性的实验研究

该澳大利亚铁矿粉是一种特殊的烧结用混合矿粉。研究其烧结基础特性,并与目前国内广泛使用的两种澳洲矿粉进行比较。其研究结果有助于中国钢铁企业通过烧结优化配矿有效使用这种特殊的铁矿粉资源。     

Influence of residuals on the metallurgical features of low carbon steel grades

The increased recycling of scrap leads in conventional steels to an increased content of undesirable trace elements. When scrap is used for steel production, the influence of precipitate‐forming or solid solution hardening trace elements in particular on the process and use properties has to be taken into account. The influence exerted by the elements niobium, titanium, chromium and molybdenum has been studied on the example of unalloyed deep drawing steels which are mainly used for the manufacture of automobiles. The production process – beginning with continuous casting, through hot rolling, cold rolling down to annealing – was simulated experimentally in laboratory equipment, and in parallel with a continuous casting simulator, forming dilatometer and high temperature conductimeter. Light‐optical microscopy and the EBSP measurements were used to characterise the pertaining microstructures. The mechanical final characteristics were determined in tensile tests. The results relating to continuous casting illustrate the influence of trace elements on precipitation, cracking, hot ductility and the phase transition from austenite in ferrite. The work softening during the hot rolling depends on the nature and the precipitation state of the foreign elements. The interplay of coiling temperature, precipitation and annealing temperature influences the softening during the annealing after the cold rolling. It could be shown that a large part of this takes place during the recovery. The analysed trace elements influence the final characteristics via hardening and grain sizes.     

Residual and trace element effects on the high-temperature creep strength of austenitic stainless steels

The heat-to-heat variation in the creep strength and ductility of austenitic stainless steels was reviewed from the viewpoint of residual and trace element effects. Based on data reported in the literature, the creep strength of unstabilized alloys such as types 304 and 316 stainless steel increased with residual element and trace element content. Niobium appeared to be the most potent strengthener. There was no direct evidence that trace elements such as sulfur and phosphorus had a deleterious effect on either strength and ductility. It was assumed that the creep strength and ductility of the unstabilized grades of austenitic stainless steels are controlled by the precipitate characteristics. It follows from this that thermomechanical treatment or residual element additions that affect the precipitate characteristics influence subsequent time dependent mechanical properties. This view is consistant with most of the information in the literature. It was concluded that more systematic studies of trace and residual element effects would be beneficial to the improvement of steels. Incorporated into the studies should be quantitative characterization of evolving precipitate morphology and composition as they are influenced by residual elements. This information should be incorporated into modeling studies of non-equilibrium segregation. Ultimately, optimum elevated-temperature strength could be developed based on a materials science approach. This paper is based on a presentation made at the symposium “The Role of Trace Elements and Interfaces in Creep Failure” held at the annual meeting of The Metallurgical Society of AIME, Dallas, Texas, February 14-18, 1982, under the sponsorship of The Mechanical Metallurgy Committee of TMS-AIME.     

1998年钼业年评

评述了１９９８年世界钼的需求、供给和价格。尤其是概述了钼新产品、新技术，诸如低合金钢、不锈钢、工具钢、铸铁铸钢、超合金、催化剂、颜料、缓蚀剂、钼肥和钼陶等的研究与开发进展。     

Influences of Alloying Elements on Oxidation Behavior of Steels and Microstructure of Oxide Scales

In order to figure out the oxidation behavior of steels during heating,five micro-alloyed steels were subjected to continuous and isothermal oxidation using the thermo gravimetric analyzer and the Gleeble-3500thermo-mechanical simulator.The microstructure of oxide scales,especially the thickness fractions of Fe2O3,Fe3O4 and FeO layers,was analyzed using the scanning electron microscope(SEM),electron probe microanalyzer(EPMA)and electron backscattered diffraction(EBSD)techniques.The micro-alloyed steels containing alloying elements(Si,Cr,Ni and Cu)show a higher oxidation resistance compared with the low carbon steel.It is found that alloying elements accumulated at scale/substrate interface during high temperature oxidation.Alloying elements function in two ways in the oxidation of steels:one is enhancing the scale/substrate interface and consequently suppressing the blister of scales;and the other is impeding the outward diffusion of iron cations from substrate to scales,resulting in the decrease of oxidation rate.As the diffusion of iron cations is impeded,the thickness fractions of Fe2O3 and Fe3O4of micro-alloyed steels are more than those of low carbon steels.     

有害微量元素对邯钢高炉炉料冶金性能的影响

为了降低有害微量元素对邯钢高炉冶炼的影响,研究了K,Na,Zn,Cl等有害微量元素对炉料冶金性能的影响,同时研究了抑制其危害的措施。研究结果表明:少量的有害微量元素即可对焦炭的冶金性能产生巨大的危害,而对于铁矿石的影响略轻,有害微量元素含量越高,炉料的冶金性能越差。在焦炭上喷洒质量浓度为0.04%的硼酸溶液,在铁矿石上喷洒质量浓度为0.04%的CaCl2溶液,可有效降低有害微量元素的危害。     

The Effect of Nb on Mechanical Properties of Quenching and Partitioning Steels

In order to study the effect of alloy elements on mechanical properties of quenching and partitioning steels,the Q and P heat treatments on different chemical composition steels were carried on in lab.The tensile test results indicated the strength of Nb+Ti-bearing steel was not increasing as expected,but lower than that of the Nb+Ti-free steel,and the elongation was raised to 26% from 9%.The Nb+Ti-bearing steel microstructures after tensile test were detected by TEM and found a certain amount of twins in the deformed microstructure while the deformed microstructure mainly was lath martensite in Nb+Ti-free steel,which means the addition of Nb and Ti elements could cause the twinning induced plasticity by inhibiting the phase transformation from austenite to martensite.Based on above analysis,adding trace Nb element could greatly increase the stacking fault energy of the retained austenite,which is beneficial to the formation of twins,and the formation of twins would lower the strength slightly and raise the elongation drastically.