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I. P. Volchok 《International Journal of Cast Metals Research》2013,26(3):162-165
AbstractThe author has examined the effect of non-metallic inclusions on the initiation and propagation of micro-cracks in a cast steel. It has been found that the first microcracks appear in non-metallic inclusions irrespective of the method of loading the samples used in the investigation. The value of the microstresses in the inclusions was measured experimentally and the effects of composition, shape and size of non-metallic inclusions on the processes leading to the generation of cracks were ascertained. The critical size of inclusions which failed to cause the formation of microcracks in steel was also determined. 相似文献
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X.Q. Bai J.C. He Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University Shenyang China 《金属学报(英文版)》2001,14(5):375-379
1. IntroductionMicro-sized non-metallic inclusibns in metal are usually detrimental to the metal ma-trix from the points of precise machining, deformation and corrosion. Therefore, theseinclusions should be removed from molten metal by using an efficient separation method.The routine methods involve floatation-separation methodology based on natural densitydifferences, ceramic filters or fine~bubble-assisted floatation-separation, and new separa-tion methods using electric or magnetic flelds h… 相似文献
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将铁水用75FeSi孕育后液淬,终止其溶解过程,在溶解区中出现已经生长石墨相的非金属夹杂物,它们随后又溶回铁水中去.但已经复盖有石墨相的晶核能存在较长的时间孕育剂的作用是提供一个碳的过冷溶液,使位于其中的非金属夹杂物活化成为晶核 相似文献
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0 IntroductionSelf-shielded flux cored wire is a newly developedwelding material used without gas protection. Use of suchcored wires has grown rapidly in developed countriesbecause of the following advantages: simple use, goodwind resistance ability, lower cost resulted from highproductivity and strong desulfurization ability[1]. Self-shielded flux cored wires are preferred for on-site weldingsuch as ship and barge building, storage tank, bridge,offshore oil platform buildings and so on[2 -3].… 相似文献
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WAMG Chunqi YANG Jiguang Tianjin University Tianjin China associate professor Faculty of Foundry Tianjin University.Tianjin China 《金属学报(英文版)》1993,6(12):411-415
Melted cast iron was inoculated by FeSi,then quenched to interrupt the dissolution,the non-metallic inclusions,in which the graphite phase was already occured,formed inthe dissolution region,They dissolved into the melt soon,but the inclusions coated bygraphite could exist for along time.The function of inoculant is to create an undercoolingsolution for carbon,thereby the non-metallic inclusions in the solution may be activatedas the nuclei for graphite. 相似文献
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针对国内某钢厂生产的含Ti微合金钢Q390(采用BOF-LF-RH-CC工艺流程),对LF处理前、LF处理后、RH处理后、中间包环节及连铸坯取样,通过光镜、电镜能谱分析及大样电解等手段研究分析了该钢种的纯净度和夹杂物演变行为。结果表明:该钢种工艺生产过程稳定,生产的钢水纯净度较高,铸坯中大型夹杂物数量为1.4 mg/10 kg,夹杂物以CaO-SiO2-Al2O3复合为主,一些大型夹杂物中复合了较高含量的Ti。另外,对钢中一些典型夹杂物的产生机理进行了阐述。 相似文献
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Impurities such as Fe, Ni and Cu and non-metallic inclusions such as oxides, nitrides, carbides, sulfides and fluorides are
harmful to the quality and various properties of magnesium alloy sheets produced by twin-roll casting. In this study, the
changes of the content of Fe and non-metallic inclusions in AZ31B magnesium alloys with melt temperature and isothermal holding
time were quantitatively evaluated using EPMA and the metallographic method. The Fe content did not increase above the Fe
content in the raw material, which implies that the dissolution of Fe from a steel crucible was suppressed effectively. The
content of non-metallic inclusions, mainly consisting of oxide, fluoride and Fe-rich intermetallic compounds, did not change
remarkably with the melt temperature but it increased with the isothermal holding time due to the continuous oxidation of
the magnesium alloy melt on the melt surface. 相似文献
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1 INTRODUCTIONAsoneofthelighteststructurematerials ,mag nesiumalloysofferlightmass(ρ<2 g·cm- 3) ,specif icstrength (higherthanthatofthealuminumalloysandsteels) ,specificstiffness ,excellentmachinabili ty ,superiordampingandmagneticshieldingcapaci ties,whichleadstoagrowinginterestinmagnesiumanditsalloys .Inrecentyears ,magnesiumalloyshavebeenwidelyusedinaviation ,spaceflight,automobileandelectronicsindustries[1] .Since 1990 stheirappli cationhassteadilyextendedanditispredictedthatitwill… 相似文献
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钢包底吹氩工艺是一种经济实用且简单易行的精炼方法,通过实验室物理模拟确定出膨胀合金4J43在底吹氩工艺中氩气流量应控制在3~7 L/min之间。在该流量范围内,合金液的混匀时间随氩气流量的增加而减少。在合适的吹氩参数下进行工业生产,实验结果表明:吹氩工艺对4J43膨胀合金中氧元素及夹杂物的去除效果明显。当氩气流量为5 L/min时,与未吹氩相比合金中氧元素含量下降56.98%,非金属夹杂物总量减少46.43%,合金中大尺寸夹杂物数量明显减少,合金在室温下的各项力学性能与同组相比均得到很大提高。 相似文献
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氧气顶底复吹转炉冶炼45#钢,其连铸坯产品用于制造热墩螺栓.生产过程中钢液的脱氧程度决定了钢中非金属夹杂物的形态和行为,直接影响到钢的冶炼品质.通过对转炉冶炼工艺终点氧的控制,对45#钢连铸坯中非金属夹杂物的形态与行为的影响做了深入的研究.提出了改善产品质量的措施和提高钢的纯净度的手段和方法. 相似文献
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非金属夹杂物在镍基粉末高温合金中的变形行为 总被引:3,自引:1,他引:2
对人工掺入FGH96合金中的Al2O3、SiO2及莫来石三种夹杂物在等温锻造过程中的变形行为进行了研究,并对夹杂内部及其周围基体中的等效应力和等效应变分布进行了模拟。结果表明,夹杂内部的应力集中是使其破碎的原因,较大的剪切应变导致其一维方向的尺寸变大,使裂纹极易在夹杂处萌生并扩展,从而增大了对基体材料的危害性。但夹杂的种类不同,在变形过程中表现出的行为特征也不尽相同:Al2O3呈破碎的“链状”分布;SiO2只发生局部破碎;莫来石呈“薄膜”状分布。通过大的变形量和挤压比,可降低非金属夹杂物对粉末高温合金盘件工程化应用的影响。 相似文献
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Investigations were carried out into the relationship between the shape and composition of non-metallic inclusions, formed in the weld metal in welding E36 and AB steels with low-alloy wires under agglomerated fluxes of the MgO–CaF2–Al2O3–SiO2 system, and the composition of the flux. It is shown that the increase in the fraction of circular non-metallic inclusions and the reduction of the fraction of elongated inclusions in the weld metal, like the reduction of the mean size of the inclusions, increase the impact work of the weld metal at the test temperature of ? 40°C. 相似文献
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电磁过滤钢液中非金属夹杂物的运动速度和去除效率的理论分析 总被引:7,自引:0,他引:7
电磁过滤原理是根据非金属夹杂物与熔体导电性的差异,在电磁场作用下非金属夹杂物与熔体的运动规律不同,使非金属夹杂物与熔体分离,经流体力学分析、采用柱塞流及轨线模型研究电磁过滤水平流动钢液中非金属夹杂物的运动速度和去除效率,结果表明,非金属夹杂物的去除效率随着熔体流速(u)和过滤器的高度(2h)的降低而增加;随着电磁力(f)、电磁力作用区长度(x)和非金属夹杂物的粒径(dp)的增加而增加,经分析表明,采用电磁过滤法可有效去除粒径小于10um的非金属夹杂物,该模型可用来设计过滤器的结构和确定电磁过滤工艺参数,为电磁去除钢液中的非金属夹杂物技术的工业应用提供理论基础。 相似文献
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利用OM和SEM研究了X100管线钢焊接接头的微观组织,并利用EDS分析接头中的非金属夹杂物种类及成分。结果表明,实验用X100管线钢焊接接头由针状铁素体、粒状贝氏体和M/A岛组成;焊缝金属中含有MnS,Si的氧化物和Al的氧化物及Al-Mg-O和Ca-Al-O-S系夹杂物。焊接接头氢致开裂敏感性较高,焊缝金属中的非金属夹杂物及硬脆M/A组元与基体之间的界面和应力导致氢致裂纹的萌生,并沿粗大的贝氏体晶粒扩展。 相似文献