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介绍了蠕墨铸铁的起源、发展、性能指标及石墨形态.按照蠕化剂的发展过程阐述镁系和稀土系蠕化剂的化学成分和加入量.简要介绍蠕墨铸铁化学成分的选择,各种预处理、蠕化处理和热处理工艺,并列举了蠕墨铸铁的应用实例,认为蠕墨铸铁将有巨大的工程应用空间. 相似文献
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稀土是一系列元素的总称,稀土中不同元素对蠕墨铸铁生产的影响不同。通过生产实践中遇到的问题来说明稀土中镧和铈的量对蠕墨铸铁生产质量的影响。结果表明,低镧蠕化剂会造成蠕化不均匀,且缩松倾向大;高镧蠕化剂,对铸件的漏渗问题有改善。 相似文献
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文章在综述了现行六种蠕化剂的缺点后介绍了西德金属服务公司(Metallgesc halt A.G.)研制的FeSiCaReMg5型蠕化剂,用这种蠕化剂生产蠕墨铸铁时具有以下特点.1.使用常规的夹层法即冲入法处理;2.不需加干扰元素;3.使用生产球铁所惯 相似文献
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影响铸铁凝固组织的隐形因素(Ⅱ) 总被引:2,自引:1,他引:1
采用冷却-凝固状态图可以预测铸铁是按白口、灰口或麻口凝固。影响铸铁碳原子析出形式的因素有:合金因素、冷却速度及熔液的核心状况。与其它合金一样,铸铁的偏析也分宏观偏析和微观偏析。合金元素和工艺因素都会影响微观偏析。 相似文献
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在汽车上使用轻质铝合金发动机可以有效减少燃油消耗和环境污染,但铝合金的耐磨损性能较差,从而造成发动机工作过程中气缸壁面容易磨损。利用表面改性技术对铝合金表面进行强化处理,可以满足其作为滑动部件在高载荷条件下的使用要求。灰铸铁较低的成本和其中石墨的自润滑作用,使其成为铝合金发动机气缸表面保护涂层材料的首选。等离子喷涂技术以其高效率和灵活性在表面强化领域受到广泛应用。因此,利用等离子喷涂制备灰铸铁涂层成为改善铝合金发动机气缸表面耐磨性的有效方法之一。但是,由于等离子喷涂过程中熔滴冷却速度极快,等离子喷涂很难得到含大量石墨组织的灰铸铁涂层。以调控灰铸铁涂层中的石墨含量为目的,总结了等离子喷涂灰铸铁涂层的研究现状,以及基体温度、颗粒尺寸、添加合金元素等对熔滴冷却速度的影响,并以此为基础,结合凝固理论分析了在涂层中保留灰铸铁粉末中的石墨组织的可行性,同时分析了在铸铁涂层中保留石墨所面临的主要问题,并提出了解决这些问题的主要措施。最后就在等离子喷涂灰铸铁涂层中保留石墨的研究方向进行了展望。 相似文献
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高硼铸造耐磨合金研究的进展 总被引:8,自引:0,他引:8
在介绍了普通铸造耐磨钢铁材料存在着韧性和耐磨性不足的基础上,提出了用含有高韧性马氏体和高硬度硼化物的高硼铁基铸造耐磨合金取代普通铸造耐磨钢铁材料的设想,着重介绍了高硼铸造耐磨合金的成分、组织、性能及其应用,指出了高硼铸造耐磨合金研究和应用中存在的问题,最后提出了开发高硼铸造耐磨合金值得重视的若干问题。 相似文献
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采用铜合金金属型和铸铁金属型浇注灰铸铁和球铁Y形试块,加入不同量的Mn、Ti、Cu和Sn,研究金属型材料和添加合金对灰铸铁和球铁抗拉强度和疲劳强度的影响。结果发现:与采用铸铁金属型浇注相比,未加合金、采用铜合金金属型浇注的灰铸铁和球铁的力学性能略高。采用铜合金铸型浇注时,由于冷速较快,使石墨和基体组织细化的作用较强,添加合金元素改善力学性能的作用较为明显,而且反复浇注时,铜合金金属型的热应力较小。因此,灰铸铁和球铁采用铜合金金属型铸造比采用铸铁金属型有利。 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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Aravind Vadiraj G. Balachandran M. Kamaraj 《Journal of Materials Engineering and Performance》2010,19(7):976-983
A high-strength and wear-resistant alloyed gray iron with ausferritic microstructure on solidification directly from molten
condition could be made in a Ni and Mo alloyed gray cast iron. The as-cast ausferritic cast iron was compared with two conventionally
austempered gray iron with and without Ni and Mo additions. The various phase constitution and volume fractions were analyzed
using optical, SEM and XRD analyses. The various aspects of the alloy chemistry and processing conditions have been correlated
with the microstructure and mechanical properties obtained. The analysis showed that the Ni-Mo alloyed austempered gray iron
and the directly as-cast austempered gray iron had similar phase constitutions. The strength of the direct as-cast alloy with
ausferritic microstructure was higher than the others due to its higher austenite content and carbide distribution. The wear
rate of the conventionally austempered Ni and Mo containing alloy and direct as-cast ausferritic alloys is 20% of the austempered
gray iron without Ni and Mo with friction coefficient less than 0.4. 相似文献
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The Fe-B alloy containing chromium and nickel was prepared, and the microstructure and erosioncorrosion behavior of the alloy were investigated by means of scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction analysis, Leica digital image analysis, a hardness tester and an erosioncorrosion tester. Cr28 white cast iron was used for comparison. Results show that the microstructures of both as-cast and heat-treated Fe-B alloys consist of austenite and borocarbide. The nickel and chromium elements are mainly distributed over the matrix and borocarbide, respectively. The hardness of the austenite matrix and the Rockwell hardness of heat-treated Fe-B alloy are higher than those of as-cast Fe-B alloy. In the erosioncorrosion test of the slurry, the erosion-corrosion weight loss of Fe-B alloy is lower than that of Cr28 white cast iron, indicating the Fe-B alloy displays higher erosion-corrosion resistance. 相似文献