Author J.H. Lee 1)
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K.B. Yoon2)
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Y.J. Kim3)and U.B. Baek4) 1) Engineering Research Department
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Korea Institute of Nuclear Safety
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P.O. Box 114
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Yoosung
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Taejon 305600
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Korea2) Department of Mechanical Engineering
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Chung Ang University
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221 Huksuk
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Dongjak
,
Seoul 156756
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Korea3) Department of Mechanical Engineering
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Sungkyunkwan University
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300 Chunchun
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Jangan
,
Suwon 440746
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Korea4) Failure Prevention Research Center
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Korea Research Institute of Standards and Science
,
P.O. Box 102
,
Yoosung
,
Taejon 305600
,
KoreaManuscript received 18 October 1998
金属学报(英文版)
Most of the assessment equations for Ct which is a wellknown fracture parameter characterizing high temperature crack growth rates, have limited applicability to constant load conditions after sudden loading. However, crack growth due to creep can also occur under load varying conditions when load rising time is so long that accumulated creep deformation near the crack tip is not negligible.In this paper, the estimation equation of the Ctparameter which can be applied to the case of slow load rising, i.e., (Ct)r, is explained. And the correlation between (Ct)r at the end of the load increasing period and Ct at the beginning of the succeeding load hold period is discussed. Finite element analyses of several cases with various loading conditions were performed and results were presented to show the effectiveness of the proposed Ct estimation scheme. The general applicability of the equation is also discussed.
关键词:
creep
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null
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null
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null
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null
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null
Author X.A. Zhang1)
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H.Q. Xia1)
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Z.T. Wu1)
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Y.F. Han1)
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R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory
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Beijing Institute of Aeronautical Materials
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Beijing 100095
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China2) The State Education Commission Open Research Laboratory for High Temperature
金属学报(英文版)
Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.
关键词:
threestage creep curve
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null
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null
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null
李国栋
稀有金属材料与工程
综述了1997年～1998年间若干磁性功能材料在研究和应用方面的若干新进展.这些新进展包括:(1)非晶和纳米晶软磁材料;(2)新的磁效应与新的磁性功能材料;(3)磁共振成象在显示生物活体电性等上的应用;(4)磁力显微镜的新应用;(5)磁浮火车从研究、试验和走向应用.
关键词:
软磁材料
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新的磁效应
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磁共振成象
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磁力显微镜
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磁浮火车
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
Corrosion Science
The SCC susceptibility of 18Cr-9Ni-Ti austenitic stainless steel in 0.5 mol.dm(-1) HCl + 0.5 mol.dm(-3) NaCl solution and the inhibiting effect of benzotriazole (BTA) on SCC and general corrosion were investigated by slow strain rate testing (SSRT), transient current measurements during fast strain rate testing (FSRT) under potentiostatic condition, scanning electron microscopy (SEM), potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) measurements. The results indicated that the inhibitive action of BTA can be attributed to its adsorption and inhibiting the anodic dissolution of the metal by the effect of blocking the active sites on the metal surface. (C) 1998 Elsevier Science Ltd. All rights reserved
关键词:
stainless steel;EIS;polarization;SEM;stress corrosion
房菲
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黄健
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李静媛
上海金属
通过热模拟试验研究了不同试验温度下,氮质量分数分别为0.07％、0.34％、0.44％和0.72％的18Mn18CrN钢的断面收缩率和抗拉强度等力学性能.结果表明:(1)18Mn18CrN钢的断面收缩率随着试验温度的升高而增大,但当温度高于1 200℃时,略有下降;(2)氮含量增加,钢具有高塑性的温度区变窄,氮质量分数为0.72％的钢,其具有最佳力学性能的温度区缩小至1 150～1200℃;(3)随着试验温度的升高,18Mn18CrN钢的抗拉强度均呈线性下降的趋势,且氮含量越高,其高温抗拉强度对温度的变化越敏感;(4)氮含量增加,18Mn18CrN钢的断面收缩率呈“V”形趋势变化.
关键词:
18Mn18CrN钢
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氮含量
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高温塑性
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试验温度
