共查询到20条相似文献，搜索用时 15 毫秒
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The work presents theoretical fundamentals of the process of refining molten steel from liquid non‐metallic inclusions, using the method of filtration with ceramic filters ‐ the thermodynamic precondition for the absorption of liquid non‐metallic inclusions on the surface of a ceramic filter. The theoretical consideration has been supported by the results of laboratory tests on the filtration of steel which was previously reduced with complex deoxidants giving liquid products of deoxidization. The filtration process of steel melts reduced with complex deoxidants of type Al‐Mn‐Si has proved to be more efficient. The deoxidation products were identified on the filtration surface of the ceramic filters. 相似文献
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The aim of this study was to investigate size distribution, chemistry, thermal stability and deformability of nano‐sulphides finer than about 100 nm formed in low carbon steel solidified under high rate of cooling and to assess the effect of the nano‐sulphides on the properties of steel. Laboratory mini‐ingots of low carbon steel containing various amounts of Mn, Cu and S, solidified under conditions simulating the direct strip casting process, were used as experimental material. Nano‐sulphides of MnS, (Mn,Cu)S, CuS, Cu2‐xS and CuS2‐x were identified in substantial quantities (volume fraction up to 3 ·10?4) using TEM techniques. It was shown that interaction between the nano‐sulphides and migrating grain boundaries of austenite occurred during annealing and in the course of thermomechanical processing resulting in grain refinement. Nano‐sulphides of MnS and (Mn,Cu)S type were also identified in significant quantities (volume fraction up to 6 ·10?4) in the shell and corner areas of commercial continuously cast billet. 相似文献
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Ever since continuous casting was introduced, nozzle clogging has been a recurring subject of metallurgical research and publications. Nozzle clogging is caused by the deposition of non‐metallic inclusions – on the casting equipment – which are solid at the temperature of casting. Calcium treatment already represents a possible solution to eliminate this phenomenon, but there are special steel grades which do not allow its application either because they are price sensitive or for certain other reasons.3 Cleaning the steel melt by agitation is an alternative solution, but it has time constraints due to the cooling of the melt. Over extensive cooling can be prevented by heating the melt (in ladle), but its introduction and operational costs per heat are often too high for an individual steelmaking plant to afford. The goal of our research is to find metallurgical solution to reduce the rate of nozzle clogging in plants which do not possess a ladle furnace and the time devoted to treatment or the price of the product do not allow Ca‐treatment to be applied. 相似文献
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Reinhold S.E. Schneider Manuel Molnar Siegfried Gelder Gerhard Reiter Carlos Martinez 《国际钢铁研究》2018,89(10)
The remelting behavior of the hot‐work tool steel X37CrMoV5‐1 is investigated with several experimental melts on a lab‐scale ESR‐plant. The investigated parameters comprise a variation of the slag compositions and the use of a protective nitrogen atmosphere. Variations of the slag composition include slags with different contents of CaF2, CaO, and Al2O3 as well as a variation of the SiO2‐content in the slag. The remelted ingots are forged and analyzed regarding their chemical composition. The distribution and composition of the non‐metallic inclusions (NMI) is studied by an automated SEM‐EDX method. Additionally, the chemical composition of the slag after remelting is analyzed. The results show clearly an equilibrium reaction between Si and Al in the steel with SiO2 and Al2O3 in the slag as well as the effect of oxygen in open ESR operation. A protective atmosphere reduces the Si‐losses during remelting, but has no major effect on the number or composition of NMI compared to open remelting. The content of NMI, especially the larger ones, is reduced significantly in all remelting experiments. The majority of the NMI are MA‐spinel type except for the CaO‐free slag, where alumina inclusions prevail. In general, remelting leads to an almost complete removal of sulfides, a reduction of oxisulfides, and a slight increase of oxides. 相似文献
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利用示踪试验,研究了在304不锈钢生产过程中,钢水接触的各种冶金熔渣对连铸坯中非金属夹杂物的影响。研究发现,AOD钢渣混出时进入钢水中的小渣滴是钢中非金属夹杂物的主要来源之一,而大包顶渣、中间包覆盖剂和结晶器保护渣不会对钢液造成明显污染。 相似文献
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This study is focused on the nails found at Inchtuthil, Perthshire (UK) dating to 87 A.D., The investigated nails were subjected to a preliminary radiographic analysis in order to point out the distribution of significant non‐metallic inclusions within the metal bulk. After the sectioning of the sample, an accurate optical microscopy examination was performed in order to study the different structural constituents of the microstructure. SEM‐EDS analysis allowed to quantitatively characterise the chemical composition of non‐metallic inclusions, while SEM‐EBSD examination revealed the crystallographic textures of the examined alloy. This information, coupled with the measurements of the micro‐hardness suggests a new hypothesis on the plastic deformation process adopted for the realization of the observed nails. 相似文献
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转炉--CAS--连铸工艺生产低碳铝镇静钢中非金属夹杂物的研究 总被引：10，自引：2，他引：10
采用添加示踪剂方法研究了转炉— CAS精炼—连铸工艺生产的低碳铝镇静钢中的非金属夹杂物 ,发现出钢或 CAS精炼过程钢包炉渣与钢液作用生成的夹杂物 ,其中尺寸在 30 μm以下的夹杂物很难从钢液中完全上浮排除。铸坯中主要的非金属夹杂物为来源于钢包炉渣与钢液作用生成的球形夹杂物、块状 Al2 O3夹杂物和簇群状 Al2 O3夹杂物。连铸坯 T[O]在 ( 1 4～ 1 7)× 1 0 - 6之间 ,非金属夹杂物含量在 2 .3mg/ 1 0 kg左右 ,表明该工艺可以生产较高洁净度的低碳铝镇静钢铸坯。 相似文献
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Krystian Janiszewski 《国际钢铁研究》2013,84(3):288-296
We propose in this publication the introduction of new, additional definition describing the multiple orifice ceramic filters used in research works on the liquid steel filtrations, calling this the filter slenderness ratio. In order to confirm the theoretical assumptions we have performed a series of the laboratory scale experiments (for the filter slenderness ratio SF1 λ = 1.67 and SF2 λ = 3.34). The influence of the filter slenderness on the filtration process efficiency has been determined through variations in quantities and surface shares of the non‐metallic inclusions in the filtrated steel in relation to the non‐filtered steel. We present also the results of researches on the separating surfaces between the liquid steel and the ceramic filter material, which in form of photos and scanning microscope microanalyses are put together in the publication. 相似文献
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A mathematical model based on the equations of particle motion was used to predict inclusion behavior observed at steel‐slag interface in an in‐situ Confocal Scanning Laser Microscope. The results show that the model can be used to explain some phenomena observed in the experiments. In addition, a parameter study was done in order to illustrate how the model can be used to study the effect of physical properties on the inclusion behavior at the slag‐steel interface for some typical industrial ladle metallurgy conditions. Furthermore, to study the effect of steel temperature, sulfur and oxygen content in the steel, slag and inclusion density as well as initial inclusion velocity on the inclusions behavior at the slag‐steel interface. The results show that the temperature and initial velocity was of less importance and that the oxygen content in the steel had a larger influence on the inclusion behavior than the sulfur content in the steel. 相似文献
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脱氧工艺对硅钢连铸坯非金属夹杂物的影响研究 总被引：1，自引：0，他引：1
研究了Al+FeSi以及FeSi两种不同脱氧工艺对硅钢铸坯中非金属夹杂物的影响。通过合理的试验设计并运用T［O］含量测定、金相分析、SEM及EDS等研究手段,对铸坯中的夹杂物进行了分析,研究表明Al+FeSi复合脱氧不仅比FeSi脱氧具有更强的脱氧能力,且能使铸坯中的夹杂物在尺寸和数量上有明显降低,夹杂物的特征也由Si O Al Mn Ti Fe系变性为以尺寸＜5 μm的Al2O3夹杂为核心、包覆Al Si S Mn Ca Ti Fe O系的复合夹杂。 相似文献
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转炉—RH—连铸工艺生产高压气瓶用钢洁净度的研究 总被引：4，自引：0，他引：4
对转炉— RH精炼—连铸工艺生产高压气瓶用钢 T[O]变化及非金属夹杂物进行研究的结果表明 ,在转炉出钢过程由于炉渣与脱氧产物作用生成的粗大球状夹杂物及铝脱氧生成的大尺寸 Al2 O3簇群状夹杂物绝大多数可由钢液排除 ,铸坯中存在的夹杂物主要是较小的块状和簇群状 Al2 O3及少量由于结晶器保护渣卷入造成的球状夹杂物。 RH精炼后钢液 T[O]在 (2 8～ 34 )× 10 - 6 之间 ,中间包钢水 T[O]在 (2 4～ 2 6 )× 10 - 6之间 ,铸坯 T[O]在 (12～ 19)× 10 - 6 之间 ,该工艺生产的气瓶用钢具有很高的洁净度。 相似文献