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1.
代位原子在Fe3Al亚点阵中的占位与合金的塑性   总被引:2,自引:0,他引:2  
采用中子衍射法测定了Cr、Mo、Ti、Ni、Mn、Si等代位原子在DO3结构Fe3Al亚点阵中的原子占位,并从解离能角度探讨了原子对之间的相互作用及合金室温塑性的影响,结果表明:Cr、MO、Ti都占据了Al原子的次近邻位置,替代Fe原子;Ni、Mn占据Al原子的最近邻位置,(Si+A)当量成分以内的Si原子替代占据Al原子的位置,由于Al-Cr原子对的结合能低于Fe-Al,AL-Mo用Al-Ti对  相似文献   

2.
王晓丹  沈宝莲 《材料工程》1995,(1):21-22,20
本文采用金相和透射电子显微镜对3CrMnMoVS塑料模具钢的微观组织进行了分析,实验结果表明,经正火处理的3CrMnMoVS钢的微观组织为形状不规则的铁基体上分布着许多粒状的组织,并有条状或纺锤状的硫化物存在。而粒状组织由上贝氏体、下贝氏体及马氏体组成,在部分铁素体中还存在部分尺寸在0.05~0.15μm 的Pe_3C相。  相似文献   

3.
介绍了16Co14Ni10Cr2MoA超高强度钢氩弧焊接头的力学性能,与40CrMnSiMoVA超高强度钢的焊接接头作了对比分析,并借助金相和电镜对接头组织进行了分析。结果表明,该超高强钢的焊接性良好,不仅接头强度高,而且塑性和韧性仍保持很高水平。  相似文献   

4.
凌斌  钟炳文 《材料工程》1995,(7):31-32,10
观察分析了冷却速度对低合金超高强度钢(40CrMnSiMoVA)精细组织的影响。结果表明,在冷却、低温等温(或回火)过程中,钢显微组织中的马氏体或贝氏体存在时效阶段。其组织特征为呢纹花样。α和ε间的取向不满足Jack关系,它属一种新的取向关系。过渡型碳化物可直接从呢纹花样区析出。  相似文献   

5.
超高强度55SiMn2Mo贝氏体钢组织和性能的研究   总被引:1,自引:0,他引:1  
通过对55SiMn2Mo贝氏体钢显微组织和力学性能的研究发现:该钢空冷条件下得到B/M复合组织,其中M为板条马氏体和孪日马氏体的混合组织,B为变态下贝氏体。55SiMn2Mo钢空冷后在250-300℃范围内回火时,可获得超高强度及较好的塑韧性配合,当回火温度超过300℃后则有回火脆性产生。  相似文献   

6.
本文研究了710-840℃之间的30CrMnSiA钢的恒温超塑性。重点测试了在共析转变点Acl点附近的超塑性指标。研究结果表明,30CrMnSiA钢具有恒温相变超塑性特性,在Acl点温度附近材料延伸率有明显增长,流动应力最低。当初始应变速率为4.2×10^-4s^-1时,经预先调质处理的30CrMnSiA钢最大延伸率为608%,最低流动应力为55MPa,与710-740℃温度区间内的研究结果相比延  相似文献   

7.
以30CrMnMoTiA钢及30SiMnMoVA钢为研究对象,进行了晶界侵蚀剂的试验,提出了用相补金相观察法来提高晶粒对比度的观点和方法。  相似文献   

8.
王茹等  朱英臣 《真空》1994,(5):13-19
本文有摩擦力监测的划痕法研究了试样参数(基体硬度、膜厚、基体表面粗糙度等)对硬质摩膜(或软膜)的临界载荷Lc的影响.样品基材是W6Mo5Cr4V2、5CrMnMo、45钢、A3钢和不锈钢.膜层为磁控溅射离子镀TiN膜和Ti膜、化学镀NiPCU膜,以及在Si3N4上溅射镀Al膜.结果发现离子度TiN膜和Ti膜与NiPCu膜规律不同,TiN膜和Ti膜的临界载荷Lc随基体硬度的提高而提高,但当基体硬度接近和超过膜层硬度时,Lc变化不大;基体粗糙度增加时Lc下降;随膜厚的增加Lc提高.而化学镀NiPCu膜的临界载荷Lc随基体硬度的提高而下降,随基体表面粗糙度的提高而增加.以W6Mo5Cr4V2为基体的NiPCu膜,随膜厚的增加Lc变化不大.本文对上述规律的实质进行了初步探讨,并对目前生产中正在推广的工具钢磁控溅射离子镀TiN膜的划痕法标准提出建议.  相似文献   

9.
(WC—Co/NiCrBSi)钎焊涂层结合机制及磨损性能研究   总被引:2,自引:0,他引:2  
采用真空钎焊工艺,将WC-Co硬质合金粉和NiCrBSi(AWSBNi-2)合金粉钎焊到45#钢表面,得到(WC-Co/NiCrBSi)钎焊涂层。  相似文献   

10.
采用真空钎焊工艺,将WC-Co硬质合金粉和NiCrBSi(AWSBNi-2)合金粉钎焊到45#钢表面,得到(WC-Co/NiCrBSi)钎焊涂层。不同钎焊工艺下,涂层及涂层/基体的拉伸强度分别达100—140MPa和300-360MPa。初步分析了钎焊涂层结合机制。涂层的磨料磨损性能远高于同配比的火焰堆焊涂层及Co-Cr-W堆焊层  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
13.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

14.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

15.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

16.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

17.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.  相似文献   

20.
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from  相似文献   

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