首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
Fe—C—Cr—Mn系耐磨合金的结构设计   总被引:3,自引:0,他引:3  
在总结了Fe-C-Cr系铸造金属基础上提出Fe-C-Cr-Mn系铸造合金碳化物体化比和奥氏体基体成分计算公式,并熔炼一系列实验合金进行了验证,按此计算了方法,可以进行Fe-C-Cr-Mn系亚稳奥氏体基耐磨合金结构设计,并为进一步实现合金结构设计的计算机模拟打下了基础。  相似文献   

2.
Cr5Mo/A302异质焊头时效过程中的组织结构变化   总被引:3,自引:0,他引:3  
利用光学显微镜对CrMo/A302异质焊头在高温时效过程中的组织结构变化进行了研究。结果表明珠江体钢/奥氏体钢划质焊头中γ-Fe与α-Fe在熔合区有结晶相适应的结晶条件;增碳层与时效时间呈抛物线关系;时效中熔合区附近碳化物转变基本遵循M7C3→M23C6→M6C;增碳层中析出碳化物与奥氏体基体保持共格关系。  相似文献   

3.
本文主要研究耐磨高铬白口铸铁的组织形貌与相结构问题。通过实验确定:比较 理想的合金主要化学组成为 Fe-11.3%Cr-2.88%C;经能谱、X射线及电子衍射 分析确认:该合金中的主要抗磨相为具有六方结构的(Cr.Fe,Mo)7C3型复合碳 化物、Hv1300—1800: 金相观测表明:该合金的显微组织形貌为:在强韧的回火马 氏体(或回火屈氏体)的连续基体上孤立匀称地分布着“菊花团伏”的高硬度共晶 碳化物(Cr,Fe,Mo)7C3。  相似文献   

4.
本文通过对 36XS,36X.HiSi-HP,Cr25Ni38,HP和 HK 等 6种奥氏体耐 热钢在渗碳过程中渗层深度的增加速度、渗碳层最高含碳量等性能的研究.利用电子 探针微区成分分析的方法,深入探讨了 Si,Ni.Cr.Fe 等合金元素在渗碳过程中  的行为和对耐热钢渗碳性能的影响.得到Si.Ni.Fe 等元素主要通过阻碍碳化物 形成而提高耐热钢的抗渗碳能力;渗碳过程中形成大量碳化物所需耍的 Cr 主要通 过渗层内基体提供.渗层内总的含 Cr 量并没增加,因渗层内基体含Cr量的显著下 降而使其耐氧化腐蚀能力下降。  相似文献   

5.
添加氧化物粉末对FeCr烧结合金交流磁特性的影响(日)大同工业大学和大同特殊钢公司技术开发研究所为进一步提高FeCr系烧结合金的交流磁特性,研究了添加SIO。、CaO、AI。O。的粉末混合物对低C的Fe-13Cr-0.SSi烧结合金磁性的影响。试验用...  相似文献   

6.
研究了铬加入高锰奥氏体钢中后,原奥氏体高锰钢组织中出现的一种新相。用X射线衍射分析确定,该相为Fe-Cr超结构相,即铬元素与奥氏体形成有序固溶体。由于铬的加入,使高锰奥氏体钢强化机制发生改变。  相似文献   

7.
用循环氧化法研究了Fe-28Al-5Cr-0.1Zr(at%)和Fe-28Al-5Cr-0.5Nb(at%)金属间化合物的高温氧化行为.结果表明,含Zr的Fe3(Al,Cr)金属间化合物在800℃、1000℃、500h循环氧化后形成一个独特的晶须状氧化物层,微量Zr能增加氧化物层与基体金属的粘附性,从而提高了该合金的高温抗氧化性能.而含Nb的Fe3(Al,Cr)金属间化合物在1000℃、350h循环氧化后形成多孔的卷绕状形貌,对Fe3(Al,Cr)金属间化合物的高温抗氧化性没有改善.  相似文献   

8.
用循环氧化法研究了Fe-28Al-5Cr-0.1Zr(at%)和Fer-28Al-5Cr-0.5Nb(at%)金属间化合物的高温氧化行为。结果表明,含Zr的Fe3(Al,Cr)金属间化合物在800℃、1000℃、500h循环氧化后形成一个独特的晶须状氧化物层,微量Zr能增加氧化物层与基体金属的粘附性,从而提高了该合金的高温抗氧化性能。而含Nb的Fe3(Al,Cr)金属间化合物在1000℃、350h  相似文献   

9.
Ni42Cr6Fe合金广泛用于制作显象管玻壳阳极帽。为了改善它作为软玻璃的气密性封接材料的性能,采用TEM、XRD、SEM等技术研究此合金表面氧化膜的组成、结构及其气密性封接性能,以选择合适气密封接的氧化膜条件。试验结果表明,氧化初期以Cr2O3为主,后期以(Fe,Mn)Cr2O4为主。氧化膜表面为(Fe,Mn)Cr2O4,主要起浸润玻璃作用;氧化膜底层为Cr2O3,主要起致密稳定和与基体连接的作用。  相似文献   

10.
本文考查了下Fe(Ⅲ)-I-、Cr(Ⅳ)-I-及Cr(Ⅳ)-I-Fe(Ⅱ)体系的反应曲线,证明由于Fe(Ⅱ)的引入,体系产生Cr(V)中间体并快速氧化I-;通过实验确定Cr(Ⅳ)-I--Fe(Ⅱ)体系的化学计量关系,导出了诱导反应的机理及速率方程,并通过反应曲线的研究进一步证实了反应机理。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号