高速钢轨中夹杂物形态及评定方法

介绍了模铸锭热轧高速钢轨中常见非金属夹杂物的形态特征，提出了生产检验中执行GB－T10561－1989标准的夹杂识别方法和评判原则。     

钢中非金属夹杂物标准图谱及评定方法的发展动态

阐述了评定钢中非金属夹杂物是研究金属结构与内在质量的一种重要方法，尤其是非金属夹杂物的显微评定方法。介绍了最新修订的ＩＳＯ４９６７－１９９８及美国ＡＳＴＭＥ４５－９７标准内容，并结合该标准对各项指标进行了对比分析。     

两种夹杂物评级方法比较

用金相法和图像仪法分别对两种不同钢材的平杂物进行评级比较。金相法检验人为因素多、误差大。图像义法检验具有连续性，结果较为精确。     

钢铁企业现行检验钢材夹杂物方法的质疑

夹杂物对钢材的性能有着重要的影响。然而,现行的夹杂物检验方法却存在着严重的问题,不能适应钢铁冶金的发展。采用非水溶液电解法研究钢中夹杂物,不仅能有效避免金相法的随机性,还能解决酸性水溶液电解法损伤夹杂物的问题,提高了夹杂物研究的准确性。     

钢中非金属夹杂物显微评定方法的比对

随着钢铁工业生产技术进步以及检测手段的提高,GB/T 10561—89《钢中非金属夹杂物显微评定方法》所规定的检测方法,逐渐显现出其局限性。新标准GB/T 10561—2005《钢中非金属夹杂物含量的测定标准评级图显微检验法》较好地解决用光学显微镜评定钢中非金属夹杂物的一系列问题,该标准图谱的显微评定方法较旧标准更加完善。     

Indirect Methods of Detecting and Evaluating Inclusions in Steel A Review

Thenonmetallicinclusionisasignificantprob lemincaststeelsleadingtoexcessivecastingrepairs orrejectedcastings.Inclusionsinsteelandinclu sions relateddefectsinsteelproductshavebeenre viewedelsewhere[1].Measurementtechniquesofin clusionsrangefromdirectmethods,whichareaccu ratebutcostly,toindirectmethods,whicharefast andinexpensive,butareonlyreliableasrelativein dicators.Indirectmethodsincludetotaloxygen measurement,nitrogenpickup,slagcomposition measurement,andsoon.Anextensivereviewon indirectmet…     

我国非金属夹杂物显微检验法的标准述评——介绍GB／T 10561

对我国非金属夹杂物显微检验法——GB／T10561标准进行述评，通过新、旧国标的变化，说明新国标更具有可操作性和适用性，弥补了原国标的不足，实现了我国非金属夹杂物显微检验法与国际标准的接轨，值得我们推广应用。     

阳极泥法提取钢中大型非金属夹杂及其大小种类测定

将钢样电解后产生的大量阳极泥，用超声波震荡筛选、淘洗，去除直径小于50μm的夹杂。存在非磁性铁锈时，用H2在350－400℃将其还原，然后将磁选后磁性部分的夹杂物在显微镜下手工分离。用分级筛测定夹杂物大小，再对典型夹杂物进行电子探针定量成分分析。试验证明，阳极泥法在硅－（半）镇静钢的应用中效果良好。     

汽车用钢国家标准体系及内容的探讨

简述了研究汽车用钢的意义,通过国内外标准主要指标的对比,找出了我国汽车用热轧钢、冷轧钢及镀层钢板标准存在的问题及解决办法.     

中间包夹杂物运动行为的数模研究

利用数学模型研究了中间包内钢水中夹杂物运动的规律,采用自编的计算机软件,对马钢板坯和异型坯中间包夹杂物的运动进行了仿真计算,结果表明,中间包内夹杂物直径＞100um时,都能在中间包内上浮,而＜5um的小颗粒夹杂则很难在中间包内上浮,90％以上都随着钢水流出中间包。加入挡墙后,直径＞50um的夹杂物都能在中间包内上浮排出。大大提高了钢水的清洁度。本文提供了一种研究中间包夹杂物运动的方法,并认可采用挡墙控制钢水流动,可有效地排除钢水中的夹杂物。     

CSP连铸薄板坯中非金属夹杂物行为研究

通过在炼钢和连铸过程的各个阶段加入不同的示踪元素,采用金相观察、大样电解、电子探针及扫描电镜等多种方法对邯钢CSP流程低碳铝镇静钢中非金属夹杂物行为进行了调查研究,找出了夹杂物的来源、数量及分布的变化规律.研究表明CSP薄板坯的洁净度水平低于传统板坯,在相同的钢种和热轧板厚条件下,邯钢CSP热轧板卷生产的冷轧板缺陷率比传统工艺热轧板卷生产的冷轧板缺陷率高62%.对结晶器EMBr实际使用效果研究表明,无电磁制动时,结晶器液面波动为±7 mm,使用电磁制动时,结晶器液面波动为±4 mm,钢中w(TO)降低了40%,大型夹杂物减少了61%.应用CFX软件数学模拟了电磁制动及无电磁制动情况下的CSP结晶器流场.模拟结果表明,在邯钢现行工艺条件下,结晶器使用电磁制动后,结晶器弯月面钢水中心线速率降低了约3倍,湍动能降低了2倍左右.结晶器钢水流动减缓,结晶器钢水卷渣明显减轻,薄板坯洁净度明显改善.     

Modification of Inclusions in Liquid Iron by Mg Treatment

Effect of Mg addition on the compositions of inclusions were studied. The results show that Mg can minimize the inclusions of steel obviously. Under the present condition, Mg deoxidation products of low-S content experimental steel would be changed in the order of Al₂O₃→MgAl₂O₄→Mg→Al–O–S→Mg–O–S. Mg deoxidation products of high-S content experimental steel generate Mg–S(–O)+MnS type inclusions, except for usual oxysulfide. And it is consistent with the results of thermodynamics calculation. Mg is preferred to react with oxide, compared with sulfide. The reaction reaches the equilibrium after 1 min or 5 min. It shows that the number and diameter of inclusions in all experimental steel samples are well under control, helping to improve the properties of steel.     

新《桥梁用结构钢》国家标准述评

新桥梁钢国家标准GB714-2000与原标准比，变化很大，牌号表示方法，化学成分，厚度适用范围，力学性能，检验和试验方法，复验等都作了较大的修改，该标准向国际国外先进标准靠拢，标准水平大幅度提高。     

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Thermodynamics calculation indicates that the stable inclusion is Al2O3 for Ti-alloyed Al-killed steel. And only when Al content is below 0. 008% does Al2TiO5 emerge. Systematical samples from practical production of Ti-IF steel reveals following discoveries. Unstable Al-Ti composite oxides formed in steel possibly due to the reaction between titanium oxides in ferrotitanium and aluminum in steel. During casting process, the aluminum loss near the melt/slag interface is more sever if the content of reducible oxide such as SiO2 is higher in tundish flux. Therefore Ti enrichment happens in partial areas near the melt and thermodynamic conditions for generating Al2TiO5 or Ti3O5 could be satisfied. In addition, titanium oxides can be easily transported into steel melt by turbulent flow.     

Oxide Inclusions at Different Steps of Steel Production

 The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, from arc furnace, ladle furnace, tundish, and continuous casting mold. Moreover, samples of slab and hot rolling products were prepared. The samples were investigated by optical and scanning electron microscopes equipped with the EDS system. According to the results, the number, composition, and kind of inclusions were directly influenced by the production variables. It was found that when the amount of dissolved oxygen was high (say more than 0002 5%), the dissolved aluminum was able to reduce silicon oxide and react with the dissolved oxygen simultaneously, whilst, the dissolved aluminum could reduce the magnesium oxide only when the oxygen content was below 0000 5%. Based on this research, a mechanism for forming the complex inclusions was suggested. It was also found that if the aluminum is added to the melt as late as possible, a cleaner melt with fewer inclusions is prepared; this method will be more effective, especially in the case of complex inclusions.