共查询到19条相似文献,搜索用时 203 毫秒
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铌钼镍对过冷灰铸铁组织和性能的影响 总被引:1,自引:0,他引:1
铌、钼、镍三种元素可使灰铸铁力学性能提高,其中以铌的综合作用最为显著,而钼对硬度影响最大。过冷灰铸铁石墨形貌的改变是力学性能提高的主要原因,钼的加入,促使自由渗碳体析出,导致硬度显著提高。 相似文献
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铌在铸铁中的作用及含铌铸铁:铸铁中的微量元素讲座之三 总被引:2,自引:2,他引:0
介绍铌在铸铁中的作用及含铌铸铁的组织和性能,其中包括铌在铸铁中的存在形态,铌对灰铸铁、过冷灰铸铁及冷硬铸铁组织和性能的影响,并对比介绍了铌、镍、钼三种元素对冷硬铸铁高温性能的影响。 相似文献
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铌在铸铁生产中应用研究与展望 总被引:6,自引:0,他引:6
铌在铸铁生产中应用与研究结果表明,微量铌元素可使灰铸铁、过冷灰铸铁及含微量铌、钼、镍三种冷硬铸铁的力学性能等得到改善。铌在铸铁中除以固溶方式存在于基体中之外,还有富铌相存在。它有三种形态,团块状的NbC相;独立存在的条状铁碳铌复杂相;与珠光体中渗碳体构成统一整体的渗碳体型铁碳铌化合物。 相似文献
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Nb、Mo含量对高钢级管线钢组织性能的影响 总被引:1,自引:0,他引:1
采用Gleeble-1500热模拟试验机并结合微观组织和力学性能测试,分析了不同铌、钼含量对管线钢的组织、力学性能和CCT曲线的影响.结果表明:随钼的质量分数增加,针状铁索体的含量增加,并且出现了M-A组织.铌在钢中可抑制奥氏体的再结晶,保持变形效果从而细化铁素体晶粒,得到细小的贝氏体组织,并且铌含量的增加使得管线钢强度和硬度鄙相应增大,冲击韧度降低.在连续冷却转变过程中,钼元素的加入使相变点温度降低,在相同的冷却条件下容易发生贝氏体转变,并使其CCT曲线向右移.而铌元素的加入增大了过冷奥氏体的稳定性,相变点温度降低,并且推迟珠光体的转变. 相似文献
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铁神一号净化剂对灰铸铁组织和力学性能的影响 总被引:4,自引:0,他引:4
利用中频感应电炉熔炼灰铸铁铁液,水玻璃砂造型,浇注铸造阶梯试样、φ30mm试棒以及热分析试样,研究了净化剂对其结晶过冷度、组织和力学性能的影响。试验结果表明,单独加入净化剂0.6%可以增加过冷倾向,细化石墨,降低断面敏感性;可以提高灰铸铁的抗拉强度和冶金质量指标;同时加入净化剂0.6%和硅钡孕育剂0.7%对灰铸铁进行复合孕育,明显增加共晶团数量至441个/cm^2,可以获得细小A型石墨,显著提高灰铸铁的力学性能σb至282MPa。 相似文献
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合金元素在ZrCr2 Laves相中的晶格占位及其对力学性能的影响 总被引:1,自引:0,他引:1
应用Rietveld模拟计算和实验X射线衍射分析合金元素V、Nb和Mo在ZrCr2 Laves相金属间化合物中的晶格占位,研究合金化对ZrCr2 Laves相力学性能的影响。研究结果表明:合金元素V和Mo占据ZrCr2 Laves相金属间化合物中Cr原子的晶格位置,而Nb则占据Zr原子的晶格;添加合金元素V、Nb和Mo使ZrCr2 Laves相化合物硬度及脆性度降低,断裂韧度显著提高,即合金化对ZrCr2 Laves相起软化作用。初步探讨合金元素对ZrCr2 Laves相力学性能的影响机制。 相似文献
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《Intermetallics》1999,7(6):731-739
Mechanically alloyed and blended Nb–Al–N powders were sintered by the spark plasma sintering process, and their microstructure and mechanical properties were investigated. All of the Nb–Al–N compacts consisted of phases in the Nb–Al system in which the Nb2N phase was dispersed. The microstructure of blended powder compacts was much coarser than that of mechanically alloyed powder compacts. The compacts obtained by sintering powder produced by crushing blended powder compacts have finer microstructure, higher hardness, and higher fracture toughness than blended powder compacts. The strength of Nb–Al–N compacts increases with increasing the fraction of AlN added to the Nb powder, while their fracture toughness at room temperature decreases. As for the Nb–Al–Mo and Nb–Al–W system, the effect of solid-solution hardening of W was larger than that of Mo, and Nb–15Al–40Mo compact has the highest strength at room temperature and 1273 K among Nb–15Al–xMo compacts. 相似文献
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《Intermetallics》2016
A series of non-equiatomic Mo–Nb–Hf–Zr–Ti alloys are synthesized to investigate the effects of the concentration variation of each composing elements on the microstructure and mechanical properties. It is found that all studied alloys form single body-centered-cubic (BCC) phase only with the variation of the lattice parameter, which indicates that the concentration variation of each composing elements has no effect on the phase constitutes. All studied alloys exhibit typically dendritic and interdendritic structure while the concentration variation of each composing elements has different effects on the microsegregation. The concentration variation of Zr leads to the most serious microsegregation. Elements with a higher melting point such as Mo and Nb solidify preferentially and thus are enriched in the dendrites. Both the increase and decrease of the concentration of each composing element reduce the hardness and strength of non-equiatomic Mo–Nb–Hf–Zr–Ti alloys compared with the equiatomic MoNbHfZrTi alloy. 相似文献
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IntroductionIMI829titaniumaloyisakindofhightemperaturenearαaloy.Itsservicetemperatureisupto580℃.IthasbeenusedinRB211525E4en... 相似文献
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To investigate the effect of tungsten addition on mechanical properties, we prepared refractory (62−x)Nb−18Si−10Mo−10Ti−xW (x=0, 5, 10 and 15 mol.%)in-situ composites by the conventional arc-casting technique, and then explored the microstructure, hardness and elastic modulus at ambient temperature and tensile properties at 1670 K. The microstructure consists of relatively fine (Nb, Mo, W, Ti)5Si3 silicide and a Nb solid solution matrix, and the fine eutectic microstructure becomes predominant at a Si content of around 18 mol.%. The hardness of (Nb, Mo, W, Ti)5Si3 silicide in a W-free sample is 1680 GPa, and goes up to 1980 GPa in a W 15 mol.% sample. The hardness, however, of Nb solid solution does not exhibit a remarkable difference when the nominal W content is increased. The elastic modulus shows a similar tendency to the hardness. The optimum tensile properties of the composites investigated are achieved at W 5 mol.% sample, which exhibits a relatively good ultimate strength of 230 MPa and an excellent balance of yield strength of 215 MPa, and an elongation of 3.7%. The SEM fractography generally indicates a ductile fracture in the W-free sample, and a cleavage rupture in W-impregnated ones. 相似文献
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A series of Ni–Cr–Fe welding wires with different Nb and Mo contents were designed to investigate the effect of Nb and Mo on the microstructure, mechanical properties and the ductility-dip cracking susceptibility of the weld metals by optical microscopy(OM), scanning electron microscopy, X-ray diffraction as well as the tensile and impact tests. Results showed that large Laves phases formed and distributed along the interdendritic regions with high Nb or Mo addition. The Cr-carbide(M_(23)C_6) was suppressed to precipitate at the grain boundaries with high Nb addition. Tensile testing indicates that the ultimate strength of weld metals increases with Nb or Mo addition. However, the voids formed easily around the large Laves phases in the interdendritic area during tensile testing for the weld metal with high Mo content. It is found that the tensile fractographs of high Mo weld metals show a typical feature of interdendritic fracture. The high Nb or Mo addition, which leads to the formation of large Laves phases, exposes a great weakening effect on the impact toughness of weld metals. In addition, the ductility-dip cracking was not found by OM in the selected cross sections of weld metals with different Nb additions. High Nb addition can eliminate the ductility-dip cracking from the Ni–Cr–Fe weld metals effectively. 相似文献
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采用铜模吸铸法制备不同直径的Fe71Mo5-xNbxP12C10B2(x=1~5)合金棒。利用X射线衍射、差热分析和压缩测试等手段分别研究Nb替换Mo对Fe71Mo5P12C10B2合金的结构、热稳定性及室温力学性能的作用。结果表明:随着Nb含量的增加,合金的玻璃形成能力有所降低,而断裂强度逐步增加;Fe71Mo2Nb3P12C10B2金属玻璃的断裂强度高达4.0GPa,且具有1%的室温压缩塑性。Fe-P-C基块体金属玻璃断裂的强度提高的原因主要是由于Nb替换Mo有利于形成似网格状结构且增强原子间结合力。 相似文献
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采用OM、SEM、TEM、拉伸试验和冲击试验等,研究了600 ℃回火不同时间对690 MPa级高强抗震耐火钢板的力学性能、微观组织及析出行为的影响。结果表明,不同回火时间对耐火钢板的力学性能和微观组织有重要影响。耐火钢板经过600 ℃回火后强度稍有降低,但伸长率增大,屈强比降低,综合力学性能提高,低温冲击吸收能量随回火时间的延长而降低。最优回火保温时间为15 min,此时试验钢板的屈服强度为976 MPa、硬度为396 HV,-40 ℃冲击吸收能量为164 J,其组织由贝氏体+铁素体+少量马氏体构成,在马氏体和铁素体中均存在位错和细小析出相,析出相为富Nb的Nb、Ti复合碳化物,发挥沉淀强化作用;当保温时间延长至60 min后,析出大量细小Nb、Ti和Mo复合碳化物,但此时的沉淀强化作用不能弥补铁素体造成的强度损失,所以在相同温度回火过程中,随着回火时间的延长,抗拉强度和硬度下降。 相似文献