共查询到19条相似文献,搜索用时 203 毫秒
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几种低合金铸铁的导热性 总被引:3,自引:1,他引:2
比较了几种低合金铸铁与HT200的导热性。指出:加入少量合金元素对铸铁导热性能影响不大;对于工作部位易发热升温而又对强度和耐磨性有一定要求的铸铁件,可选用低合金铸铁。 相似文献
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高铬铸铁轧辊的生产工艺 总被引:5,自引:4,他引:1
为提高高铬铸铁轧辊的硬度和耐磨性,生产中从化学成分的选择、铸造工艺的分析以及热处理工艺等的研究方面探讨它们对高铬铸铁的组织和性能的影响.高铬铸铁试样经过高温淬火和中温回火(1070℃+450~480℃)后,其硬度高于铸态试样的硬度值,其耐磨性为铸态试样的1.61倍.用此工艺制造的高铬铸铁轧辊强度大、硬度高、耐磨性较好. 相似文献
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研究了低铬耐磨铸铁经40%热变形及不同方式冷却后的组织与耐磨性的关系。结果表明:该铸铁经热变形后的组织与耐磨性有良好的对应关系,其耐磨性随硬度的增加而增大,同时也与组织中碳化物的形状、大小及分布有关。 相似文献
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研究了低铬耐磨铸铁经40%热变形及不同方式冷却后的组织与耐磨性的关系。结果表明:该铸铁经热变形后的组织与耐磨性有良好的对应关系,其耐磨性随硬度的增加而增大,同时也与组织中碳化物的形状、大小及分布有关。 相似文献
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含磷蠕墨铸铁闸瓦的研制 总被引:1,自引:0,他引:1
本文研制了一种新型材质的闸瓦—含磷蠕墨铸铁闸瓦。试验结果证明,一定量的磷加入蠕墨铸铁中,其硬度、抗拉强度均满足闸瓦的使用要求而耐磨性可达到中磷灰铸铁闸瓦的2倍以上。磷加入蠕墨铸铁中使得蠕墨铸铁的磷共晶数量增加而石墨数量减小,因此使得其强度降低,硬度升高,闸瓦的耐磨性提高。 相似文献
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一引言贝氏体铸铁早在四十年代初就有过报导,其强度、硬度、塑性和韧性都远远超过珠光体铸铁。下贝氏体铸铁的极限强度可达120公斤/厘米~2,冲击韧性可达6公斤米/厘米~2以上,耐磨性相当于油淬马氏体,比珠 相似文献
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通过在药芯焊丝中添加锆元素来制备含锆高铬铸铁堆焊层,用扫描电镜及EDS对高铬铸铁堆焊层中锆元素的存在状态进行观察分析,且对含锆和不含锆材料的宏观硬度及耐磨性进行测定。结果表明,锆在高铬铸铁堆焊层中全部是以碳化锆的形式存在的。碳化锆的数量与含锆量有关。铬及铁元素不进入碳化锆颗粒,锆元素也不进入碳化铬及基体。堆焊层的硬度及耐磨性试验证明,加入锆元素后材料的宏观硬度有所提高,但其耐磨性有所降低。 相似文献
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In the case of employing brake discs as a key component of mechanical brake equipment, the initiation of thermal cracking
owing to repetitive thermal shock generated during braking may potentially lead to higher maintenance costs, worsened braking
performance, and greater risk of railway accidents. The purpose of this study is to gain basic data to facilitate application
of compacted vermicular (C. V.) graphite cast iron to brake discs in order to obtain high thermal crack resistance and improved
lifetime. To this end, this study developed three types of C. V. graphite cast iron with differing content of key elements,
including Ni, Cr, and Mo. Each test specimen underwent numerous tests for evaluation of materials characteristics, and the
results were compared with those obtained for existing materials. The test results show that the thermal fatigue lifetime
of material C is nearly double that of the conventional material. This demonstrates the suitability of material C as a material
for brake discs in mid- to high-speed railway vehicles. 相似文献
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O. Maluf M. Angeloni D.B.V. Castro W.W. Bose Filho D. Spinelli C.O.F.T. Ruckert 《Journal of Materials Engineering and Performance》2009,18(7):980-984
The purpose of this work was to experimentally investigate the thermal diffusivity of four different gray cast iron alloys,
regularly used to produce brake disks for automotive vehicles. Thermal diffusivity measurements were performed at temperatures
ranging from room temperature to 600 °C. The influence of the thermal conductivity on the thermomechanical fatigue life is
also briefly presented. The measurements were sensitive to the influence of the carbon equivalent and alloying elements, such
as molybdenum, copper and chromium. Molybdenum, unlike copper, lowered the thermal diffusivity of the gray cast iron, and
alloy E (without molybdenum), besides presenting a relatively low carbon equivalent content and an increase in the values
of the thermal diffusivity, presented the best performance during the thermomechanical fatigue. The molybdenum present in
alloys B and C did not fulfill the expectations of providing the best thermomechanical fatigue behavior. Consequently, its
elimination in the gray cast iron alloy for this application will result in a significant economy. 相似文献
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Z.L. Ding Y.C. Fan H.B. Qi D.L. Ren J.B. Guo Z.Q. Jiang Shijiazhuang Railway Institute Shijiazhuang China 《金属学报(英文版)》2000,13(4):974-980
1. IntroductionThe SiC particulate reinforced aluminum matrix composites (AMC) have sucll characteristics as high specific stiffness and strength, high wear resistance, high thermal condllctivity, and lightweight etc. Using such lightweight material, as aluminum matrix compositein brake systems is one of the ways to reduce unsprung weight of motor vehicles. Thetribological and wear behavior of the aluminum matrix composite have been reported bydifferent ...ea.chers[1--4], and AMC brake roto… 相似文献
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Al2O3短纤维/SiC颗粒混杂增强铝合金复合材料 总被引:9,自引:2,他引:7
研究了Al2O3 短纤维和SiC 颗粒混杂增强铝合金复合材料在制动过程中的摩擦磨损性能。结果表明复合材料在制动过程中的摩擦系数较稳定, 磨损量较小, 与传统的制动材料铸铁相比, 复合材料的表面温升较低, 铸铁由于表面温升较高而产生了大量的裂纹。复合材料由于增强体的存在, 制动过程中表面易形成致密连续的转移膜, 该转移膜的出现保证了复合材料在制动过程中摩擦系数的稳定, 降低了复合材料的磨损量。与铸铁相比, 复合材料的密度较低, 更适用于作制动材料 相似文献
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M. Nili Ahmadabadi S. Nategh P. Davami 《International Journal of Cast Metals Research》2013,26(4):188-194
AbstractCastings are very widely used for critical friction and wear applications. As operating conditions are becoming more arduous, greater demands will be placed upon the casting industry to meet the requirements of the designer. This study was undertaken to evaluate the wear resistance of 2.5% Ni, 0.4% Mo austempered ductile iron, having a hardness of HB 270 and a high amount of retained austenite, in the particular context of a railway braking application. Pin-wear test data is presented, comparing wear behaviour of this ADI grade with that of a pearlitic grey cast iron which is currently employed as a brake block material in Iranian passenger trains, and with a 3% P cast iron which was developed in the UK.1 相似文献