共查询到19条相似文献,搜索用时 203 毫秒
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稀土,钛对渗硼层组织和性能的影响 总被引:2,自引:0,他引:2
研究了不同的稀土硼钛共渗处理工艺及其对组织和性能的影响。和纯渗硼层相比,发现共渗层具有高的显微硬度和低的硬度梯度、高耐磨性和热疲劳性;渗层组织致密,与基体结合良好。结果表明,稀土和钛对渗硼层具有明显的改性作用,同时发现稀土在三元共渗中具有明显的催渗作用,可使渗速提高30% ~50% 以上。根据工艺和性能得出稀土最佳浓度为3% ~4% ,TiO2 为4% 。 相似文献
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稀土含量对38CrMoAl钢渗氮层性能的影响 总被引:1,自引:1,他引:0
为了克服38CrMoAl钢渗氮速度慢,渗层脆性大,稀土添加到渗氮气氛中只能作用于工件表面等缺点,研究了38CrMoAl钢中不同稀土添加量对渗氮层性能的影响,并初步分析了其影响机制。研究结果表明:稀土对38CrMoAl钢渗氮具有明显的催渗作用,且能提高渗层性能。原因是稀土加入钢中后,引起周围铁原子的点阵畸变,有利于氮原子的吸附和扩散,且稀土易与渗氮气氛中的氧结合,削弱了氧对渗氮的阻碍作用;同时稀土的晶粒细化、固溶体强化、微合金化也是其改善渗层性能的重要原因。 相似文献
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钢的稀土硼铬共渗层耐磨损性能的研究 总被引:2,自引:0,他引:2
通过对钢单渗硼层和稀土硼铬共渗层的硬度、脆性和磨损特性进行研究。结果表明,稀土硼铬共渗层在保留了单渗硼层高硬度的同时,明显降低了脆性(约为42.7%),使共渗层的粘着磨损、疲劳磨损和磨粒磨损性能都得到较大的提高,有较强的实用性。 相似文献
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4Cr5MoSiV1钢硼铝稀土共渗层的组织与性能 总被引:2,自引:1,他引:2
通过扫描电镜、能谱分析、X射线衍射分析等方法,对4Cr5MoSiV1钢硼铝稀土共渗层组织与性能进行了研究。结果表明,共渗层主要由FeB相构成,没有发现(Fe,Al)B或(Fe,Al)2B物相;共渗层组织连续致密,具有很高的显微硬度和热硬性。 相似文献
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分析了重载汽车同步器齿环精锻模具的失效形式及原因,从材料及模具结构进行了优化,介绍了模具用钢的强韧化热处理工艺,改进后模具的强度、抗热疲劳性、红硬性和韧性等充分加强,材料性能得到很好发挥,生产证明,模具寿命达2 000模次以上,取得了预期的效果。 相似文献
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The effects of rare earth elements on the corrosion properties of low-carbon steel and weathering steel were investigated. To elucidate the roles of rare earth elements (Ce and La) and the corrosion behavior of steels, salt spray tests, electrochemical techniques, X-ray diffractometer, scanning electron microscopy, Electron Probe Micro Analysis (EPMA), and Auger Electron Spectroscopy (AES) were conducted. The results showed that the addition of rare earth elements enhances the corrosion resistance of both low-carbon steels and weathering steels, indicated by lower corrosion current density and salt spray corrosion rate after rare earth alloying. On the one hand, rare earth elements modify the morphology of inclusions and thus slow down the micro-area electrochemical corrosion, which improves the electrochemical corrosion resistance of these two steels. On the other hand, rare earth atoms tend to segregate toward the interface between the rust layer and the matrix. Hence, salt spray corrosion resistance is improved due to the enhancement of adhesion and compactness of the rust by the addition of rare earth elements. 相似文献
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《International Heat Treatment & Surface Engineering》2013,7(4):175-179
AbstractThe application of surface treatment methods like ion nitriding, physical vapour deposition (PVD) coatings and their combination in duplex treatments effectively reduces the occurrence of oxidation, corrosion, erosion and wear processes. However, it is still uncertain whether nitriding and duplex treatment have any real effect on the decrease in the nucleation and growth of thermal fatigue cracks on the surface. This paper presents the results of thermal fatigue investigations of a nitrided layer and different composite layers ‘nitrided layer/PVD coating’ (TiN, CrN and TiAlN) obtained on the EN X40CrMoV5·1 hot working steel. The ion nitrided only and three different duplex treated substrates were compared, based on the intensity of the thermal fatigue cracks observed after testing. The nitrided layer and composite layers investigated were obtained with the use of the hybrid surface treatment technology consisting of ion nitriding followed by arc evaporation coating deposition. Apparatus based on high frequency induction heating and water spray cooling was used for thermal fatigue tests under the following conditions: maximum temperature 600°C, minimum temperature 80°C and two different rates of thermal cycling: 500 and 1000. The thermal fatigue intensities of the nitrided layer and the three different composite layers were measured according to the surface crack density and crack length (i.e. penetration into the testpiece) after different numbers of thermal cycles. Finally, based on the results obtained, the influence of different PVD coatings in the composite layer on the increase in thermal fatigue resistance of hot working steel was discussed. 相似文献
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表面改性过程中加入稀土元素对改善材料表面的摩擦学性能有显著的效果.稀土表面工程研究中可通过多种方法将稀土元素加入表面改性层,通常采用化学热处理、热喷涂和喷焊、激光表面处理等方法.本文综述了哈尔滨工业大学材料科学系的研究者们在该领域的研究情况,包括本文作者的研究和应用成果. 相似文献
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Chen Ying Nie Zuoren Zhou Meiling Zhang Jiuxing Zuo Tieyong BXSchool of Materials Science Engineering Beijing Polytechnic University Beijing P. R. China 《中国有色金属学会会刊》1999,9(2)
1INTRODUCTIONInrecentyears,tungstenelectrodematerialscontainingonekindofrareearthmetaloxideasLa2O3,CeO2andY2O3,havebeendevel... 相似文献
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为了研究稀土元素对钢中夹杂物的改性影响,以未添加稀土元素的Q235和添加了稀土元素的Q235RE两种耐候钢为研究对象,采用非水溶液电解萃取和物理磁选分离的方法提取出钢中的夹杂物,结合X射线衍射仪、扫描电镜和能谱仪分别对其类型、三维形貌进行研究。研究结果表明:未添加稀土元素的Q235钢中的夹杂物类型主要是硫化锰和铝、硅的复合氧化夹杂,且尺寸较大,呈现不规则多角状的镁铝氧化物、氧硫复合夹杂物尺寸可达40 μm,长条状硫化锰夹杂尺寸可达50 μm;稀土耐候钢Q235RE中夹杂物的类型主要是氧硫稀土复合夹杂物,夹杂物尺寸明显变小,长条状的硫化物被规则的球状的稀土硫化物及稀土氧硫复合夹杂物所取代,不规则多角状的氧化夹杂物尺寸小于15 μm,尺寸减小了约60%。 相似文献
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Effect of Micro-addition Rare Earth and Chrome on Friction and Wear Behavior of Boronized layer 总被引:1,自引:0,他引:1
XU Bin'''' WANG Shu-hua l LU Yu-peng CUI Jian-jun LI Mu-sen . Dept. of Mater. Sci. & Engineering Shandong Institute of Architecture Engineering Jinan China . Institute of Mater. Sci. & Engineering Shandong University Jinan China 《材料热处理学报》2004,25(5)
BORONIZED LAYER refers to the columnar boridelayer composed of FeB+Fe2B dual phases or singleFe2B phase.When subjected to thermal stressmicro-cracks in FeB+Fe2B dual phases are easier toarise and extend as compared to those in single FeaBphase,because of the differences of specific volumesand coefficients of linear expansion between FeB andFe2B[1].So the boronized layer composed of singleFe2B phase has always been expected to be obtained forthe parts to be boronized.The growth of b… 相似文献