共查询到18条相似文献,搜索用时 171 毫秒
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研究了铌对高铬锰白口铸铁断裂韧度和耐磨性的影响规律。结果表明:在高铬锰白口铸铁中加入适量的铌,能提高断裂韧度和耐磨性,在使用较软磨料时,含铌0.5%的高铬白口铸铁,经650℃预处理和850℃淬火后,具有较好的耐磨性和断裂韧度的配合。 相似文献
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在白口铸铁中加入微量铌元素,通过其抗磨损试验,组织,磨面及磨电镜观察分析,研究了铌元素及热处理工艺对白口铸铁抗磨损性能的影响 相似文献
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Hardy Mohrbacher 《现代铸铁》2011,(2):28-33
介绍了铌合金在灰铸铁、球墨铸铁、不完全激冷(indefinite chill)铸铁和镍抗可焊接(weldable Ni-Resist)铸铁中的应用情况;分析了铌合金在铸铁中的作用机理,认为NbC能为共晶团提供核心是加Nb细化共晶团的原因,而且NbC的弥散分布可以提高铸铁耐磨性、硬度和强度;综述了铌合金化技术原理,指出铸铁加铌合金化主要有与固体废铁料一起加入大块料和出铁时加入细颗粒两种较为经济的方法。 相似文献
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概述了含铌铸铁,含硼铸铁,含钒、钛、稀土白口铸铁,镍硬铸铁和高铬白口铸铁生产工艺的进展情况;介绍了在各种不同磨料磨损条件下高铬铸铁的化学成分及显微组织的恰当选择;指出通过细化碳化物,高铬白口铸铁的冲击韧性可以得到提高。 相似文献
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本文采用廉价钛铁、铌铁和含碳材料等.以焊条药皮合金化,通过电弧冶金反应,获得含TiC、NbC超硬质相的堆焊层。极大地提高了堆焊层的耐磨性。研制出含TiC-NbC新型耐磨合金堆焊条。具有广泛地应用前途。 相似文献
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铌对高铬锰白口铸铁组织和性能的影响 总被引:6,自引:0,他引:6
研究了铌对高铬锰白口铸2的组织和性能的影响规律。结果表明,在高铬锰白口铸铁中加入微量的铌能细化晶粒。改善碳化物的形貌和分布。当铌加入量为0.2%时,在850℃淬火,力学性能获得最佳配合,冲击韧度为7j/cm^2,硬度的62HRC。 相似文献
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《铸造技术》2019,(10):1035-1038
采用原位反应与两步法热处理结合方法,使铌丝提供的铌原子与灰口铸铁中石墨提供的碳原子发生原位自生反应,制备了NbC增强铁基复合材料。采用XRD、SEM、TEM等检测手段对复合材料的物相组成与组织结构进行分析,利用显微硬度计对复合材料进行硬度与显微压痕形貌及压痕裂纹分析。结果表明,通过原位反应成功制备了NbC增强铁基复合材料,该复合材料的主要物相组成为α-Fe、Nb、NbC、G。NbC/Fe陶瓷层的厚度约为242±3μm,NbC/Fe陶瓷层与Nb丝、铁基体之间呈现良好的冶金结合。NbC陶瓷颗粒形貌为标准的立方体,NbC/Fe陶瓷层的显微硬度是铁基体的3~4倍。 相似文献
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Mervat Mohamed Ibrahim Shimaa El-Hadad Mohamed Mourad 《International Journal of Cast Metals Research》2018,31(2):72-79
The effect of niobium additions on the as-cast microstructure of a hypoeutectic high-Cr cast iron containing 2.2 wt.% C and 16.5 wt.% Cr was investigated. With increasing niobium content, the eutectic M7C3 carbides were refined and became less elongated as well as its volume fraction was decreased gradually. The first precipitated NbC particles could be act as heterogeneous substrate of proeutectic austenite and a barrier to M7C3 grain growth. The morphology of NbC carbides changed with increasing niobium content. Such NbC particles were increased with increasing Nb content and subsequently contributed to increased hardness. Optimum toughness was obtained for the irons alloyed with 2.14% Nb. The effects of applied load and Nb-additions on wear resistance of high chromium cast iron have been studied. The results showed that wear resistance increases with increasing Nb addition. Furthermore, the effectiveness of the NbC particles on the weight loss was more evident at higher loads. 相似文献
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The effect of niobium on the formation of NbC phase and solidification structure in high carbon equivalent grey cast iron was investigated.The experimental results indicated that an increase in the niobium content is favorable to refining the graphite and eutectic cell;and the pearlite lamellar spacing is reduced.Based on the thermodynamic calculation the formation of NbC is prior to the eutectic reaction.The reduction in the pearlite lamellar spacing is mainly attributed to the decrease of eutectic tempera... 相似文献
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Arnoldo Bedolla-Jacuinde 《International Journal of Cast Metals Research》2013,26(6):343-361
In the present work, additions of 2% vanadium, 2% niobium and 2% titanium were respectively made to a high-chromium white iron (17% Cr) to analyse the effect of these elements on the as-cast structure of the alloy, and their influence on the material's hardness. This study was carried out for different solidification rates, so the alloys were cast into wedge-shaped copper moulds. The recorded solidification rates for the ingots ranged from 1.5 K sec?1 for a 2 mm thickness section, to 35 K sec?1 for a 40 mm section. It was found that the addition of these carbide forming elements considerably increased the alloy's hardness by different mechanisms. Vanadium was shown to partition completely to the eutectic carbide phase which increased hardness and the volume fraction of this phase. Niobium and titanium formed extremely hard NbC and TiC respectively, which in turn produced a refinement in the structure and contributed to the increase in hardness of the iron. There was no evidence that these elements influenced the size and morphology of the eutectic carbide M7C3 for the experienced solidification rates. 相似文献
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铸态合金耐磨铸铁适用于大型或复杂结构耐磨件。通过金相组织观察、X射线衍射相结构分析、图像分析仪定量金相测试和力学性能检测,研究了含钨量对铸态290Cr26MoW耐磨铸铁组织、结构和硬度的影响规律。结果表明,在含0~2.79%W的范围内,随着含W量的增加,铸态290Cr26MoW耐磨白口铸铁的初生基体数量减少,共晶团数量增加,共晶碳化物数量增加;铸态290Cr26MoW耐磨白口铸铁的碳化物结构类型没有改变,M7C3型碳化物为共晶碳化物;铸态290Cr26MoW耐磨白口铸铁基体的奥氏体比例增加,马氏体减少。马氏体多位于共晶团,即共晶碳化物周围。铸态290Cr26MoW耐磨白口铸铁的硬度由共晶碳化物数量和硬度以及基体中奥氏体和马氏体数量比共同决定。 相似文献
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C、Cr、Si、Mn对低铬白口铸铁组织和力学性能的影响 总被引:1,自引:0,他引:1
应用湿砂铸型浇注低铬白口铸铁,采用正交试验研究了C、Cr、Si、Mn对低铬白口铸铁组织和力学性能的影响。结果表明:含碳量2.4%和2.7%时碳化物基本上是呈网状分布的,形成了离异共晶的网状碳化物组织;而含碳量3.0%时,离异共晶组织不再出现。高碳、低硅、高铬和低锰有利于提高硬度;低碳、低硅、中铬和高锰有利于提高冲击韧度;高碳、低硅、低铬和高锰有利提高耐磨性。新开发的低铬白、口铸铁的硬度、冲击韧度和耐磨性远高于目前在生产排沙潜水泵过流部件中所使用材料的各项性能,使用寿命是其5倍左右。 相似文献
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The effects of trace additions of multi-alloying elements (Ti,Nb,V,Mo) on carbides precipitation and ascast microstructure of eutectic high chromium cast iron containing 2.85wt.%C and 31.0wt.%Cr were i... 相似文献
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《International Journal of Cast Metals Research》2013,26(2):130-133
AbstractThe effect of semisolid heat treatment on the microstructures of three chromium white cast irons has been studied. The primary objective was to examine the effect of semisolid heat treatment on the microstructures with specific emphasis on revealing the variations related to the carbide morphology of the selected materials. It is found that graphitization of carbide in a 1·5 wt.% chromium cast iron is enhanced during isothermal heat treatment in the semisolid state. The eutectic carbide in high chromium cast irons is fully or partially modified into discrete particles during heat treatment in the semisolid state. 相似文献