共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
5.
Alargenumberofaustemperedductileiron (ADI)partshavebeenproducedsinceADIwasdevelopedin 1 977.Itisoneofgreatachievementsformetallurgyofcastironinre centtwentyyears .AfterADI,attentionhasal sobeenpaidtoaustemperedvermiculargraphitecastiron (AVGCI)owingtoitsgoodp… 相似文献
6.
设计了新型耐蚀镍铸铁的组织及其化学成分。试验结果表明,除了石墨和奥氏体基体外,还有合金渗碳体存在。该镍铸铁具有良好的耐蚀性能、较好的机械性能与满意的铸造性能。 相似文献
7.
稀土铁基自熔基合金抗硫化氢腐蚀性能的实验研究 总被引:1,自引:0,他引:1
近年来关于稀土在热喷涂(焊)材料中的应用研究正日益受到人们的重视。铁基自熔合金末作为一种广泛使用的热喷涂(焊)材料具有价格低廉,喷涂(焊)层的耐磨性较好等优点,但其耐蚀性较差。为此,本研究引入稀土对其改性。通过熔炼-雾化工艺制备了稀土铁基自熔合金粉末,并考察了稀土对铁基自熔合金喷焊层在硫化氢介质中气蚀和在含硫化氢的中性氯化钠溶液中浸蚀的影响。结果表明,铁基自熔合金(含稀土和不含稀土)喷焊层试样表现出较强的抗硫化氢能力。铁基合金喷焊层试样在含硫化氢的4Wt%NaCl溶液中的腐蚀速率随稀土的添加量增加量增加而逐渐降低,且稀土添加量有最佳值0.2Wt%。 相似文献
8.
Gray cast irons were inoculated with FeSi75+RE and FeSi75+Sr inoculants. The changes of apex angle of the drills before and af-ter being used were used to evaluate machinability of gray cast irons. Effect of FeSi75+RE and FeSi75+Sr inoculants on mechanical proper-ties, machinability and sensibility of gray cast iron used in cylinder block were investigated. Experimental results showed that gray cast iron treated with 60%FeSi75+40% RE inoculants exhibited tensile strength consistently at about 295 MPa along with good hardness and im-proved metallurgical quality. While gray cast iron inoculated with 20%FeSi75+80% Sr inoculants exhibited the best machinability, the low-est cross-section sensibility and the least microhardness difference. The tool flank wear of the drill increased correspondingly with the in-crease of the microhardness difference of the matrix, indicating the great effect of homogeneity of the matrix on the machinability of gray cast iron. 相似文献
9.
为了提高材料在水泥混凝土搅拌和输送工况下的使用性能,以新研制的耐磨耐蚀铸铁为对象,采用复合变质处理的方法研究了变质剂加入量对该试验合金铸铁组织、力学性能和耐腐蚀磨损性能的影响。研究结果表明,复合变质处理可以细化耐磨耐蚀铸铁基体组织、消除柱状枝晶,改善碳化物形态、尺寸及分布,使碳化物由变质前的粗大棒条状变为均匀分布的短棒状和颗粒状,消除了粗大片状碳化物对材料基体的危害,使耐磨耐蚀铸铁的性能得到改善。变质剂加入量增加,耐磨耐蚀铸铁的冲击韧度和耐磨耐蚀性能均有较大提高。与变质前相比,加入0.25%和0.50%复合变质剂处理的试验合金铸铁,其冲击韧度和相对耐腐蚀磨损性能分别提高了22.9%、58.3%和16%、23%,基体硬度略有降低,达到了预期效果。 相似文献
10.
EffectofREComplexInoculationontheFatigueWearBehavioursofHighChromiumCastIronWangJiubin(InstituteofIron&SteelResearch,AnshanIr... 相似文献
11.
An apparatus of zone melting unidirectional solidification with a steep temperature gradient andan impact fatigue tester were used.The effect of RE elements on the morphology of carbides and the impactfatigue properties of the low Cr white cast iron were investigated.Experimental results showed that the modi-fying effect of RE elements was remarkable on the M3C carbides.With the addition of RE elements in thelow Cr iron,a lot of plate-like carbides were transformed into lath-like and rod-like ones.The higher thecontent of RE elements was,the more was the fraction of the lath-like and rod-like carbides.In the low Crwhite cast iron,the RE modifying agent can efficiently increase the impact fatigue resistance and decrease thecrack growth rate and delay the time of incipient cracking.With the increase of the content of RE elements inthe low Cr cast iron,the impact fatigue resistance increased greatly and the crack growth rate decreased rap-idly. 相似文献
12.
Qi Sui Hong Zhou Deping Zhang Zhikai Chen Peng Zhang 《Metallurgical and Materials Transactions A》2017,48(8):3758-3769
The present study aims to create coupling biomimetic units on gray cast iron substrate by laser surface treatment (LST). LSTs for single-step (LST1) and two-step (LST2) processes, were carried out on gray cast iron in different media (air and water). Their effects on microstructure, thermal fatigue, and post-thermal-cycle wear (PTW) resistance on the specimens were studied. The tests were carried out to examine the influence of crack-resistance behavior as well as the biomimetic surface on its post-thermal-cycle wear behavior and different units, with different laser treatments for comparison. Results showed that LST2 enhanced the PTW behaviors of gray cast iron, which then led to an increase in its crack resistance. Among the treated cast irons, the one treated by LST2 in air showed the lowest residual stress, due to the positive effect of the lower steepness of the thermal gradient. Moreover, the same specimen showed the best PTW performance, due to its superior crack resistance and higher hardness as a result of it. 相似文献
13.
Magnesium alloys are widely used as shells of 3C (computer, mobile phone and consumer electronics) equipments for its impressive mechanical and physical properties, such as low density, good resistance to electromagnetic radiation, suitable for high pressure diecasting and easily recycling, etc. But poor corrosion resistance confines its extensively application. In this paper, protective coatings was successfully prepared on AZ91D magnesium alloys by micro-arc oxidation (MAO) and painting process. Microstructures and phases of MAO coatings were invesgated with scanning electron microscope (SEM) and X-Ray diffractometer. Mechanical properties of MAO coating, such as adhesive force and corrosion resistance, were also tested. Results showed that MAO coatings were a good base for painting process. MAO coatings with paint have good adhesive properties to base metal and excellent corrosion resistance. Micro-arc oxidation with painting process is a good kind of surface treatment to improve the corrosion resistance of mobile phone shell made of AZ91D magnesium alloys. 相似文献
14.
Continuously cast aluminium alloy wires containing active elements such as yttrium, cerium, lanthanum or silicon were used as evaporation sources for ion vapour deposition on nickel‐based Inconel IN738 and stainless steel 310S substrate materials. The samples were subsequently diffusion heat‐treated to form protective corrosion resistant nickel aluminide and iron aluminide coatings. The coated alloy materials were exposed for prolonged periods to high temperature cyclic oxidation, molten sulphate, and molten carbonate environments to evaluate their resistance to hot oxidation. For IN738, the lanthanum‐modified aluminide coating provided good thermal cyclic oxidation performance while the cerium‐modified coating exhibited effective hot corrosion resistance in a molten sulphate environment. For 310S stainless steel, all of the modified aluminide coatings provided equally good corrosion protection when exposed to molten carbonate attack under an oxidizing atmosphere. 相似文献
15.
研究了高铬铸铁的抗高温氧化性能、耐激冷激热性,以及钒和各种合金元素对高铬铸铁耐热性能的影响。研究结果表明,钒对高铬铸铁的耐热性有着明显的不良影响。因此,必须严格控制用于冶金条件的高铬铸铁中的钒含量。 相似文献
16.
EfectofRareEarthsandNitrogenonGraphiteStructureofGrayCastIronZhaiQijie(翟启杰),ZengQi(曾奇)(FoundryInstitute,UniversityofSciencea... 相似文献
17.
Effect of RE Modification and Heat Treatment on Impact Fatigue Property of a Wear Resistant White Cast Iron 总被引:5,自引:0,他引:5
Withhigherhardnessandbetterwearresistance ,whitecastironscanbeusedaswearresistantpartsinmanyfields .Inpractice ,thewearresistantpartsareoftenrequiredtobesubjectedtogrindingofabrasivesandrepeatedimpactaction .Therefore ,fatiguecracksareliabletobegeneratedo… 相似文献
18.
19.
改进型高铬铸铁篦条的研究 总被引:2,自引:0,他引:2
烧结机炉篦条的主要失效形式是烧蚀和折断.为了提高炉篦条的强度和耐蚀性能,对其成分进行优化设计.高铬铸铁中加入适量的Al和Si,以提高其抗氧化性,此外还加入适量的B、Ar和Y,使其组织细化,有利于高铬铸铁力学性能的大幅度提高,最终提高高铬铸铁篦条使用性能.此外,篦条制造中还采用了过滤处理工艺,以减少铸造组织中的夹杂物数量,提高铸铁的强度、韧性和抗氧化性.国产改进型高铬铸铁篦条在450m2大型烧结机台车上使用,篦条消耗9~12 g/t,使用寿命超过3年. 相似文献
20.
稀土变质处理高硅铸铁的研究与应用 总被引:2,自引:0,他引:2
研究了稀土对高硅铸铁的组织与性能的影响,试验结果表明:在高硅铸铁中添加适量的稀土,可使石墨由晶间网状或片状集分布变为弥散的颗粒状均匀分布,并使其组织细化与无效化,因此,明显地提高了高硅铸铁的机械性能,耐蚀性能和铸造性能。 相似文献