L.M Ma
,
G.J. Liang
,
CG. Fan
,
and Y Y Li(Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
Effects of γ, η precipitates and grain size on hydrogen damage (HD) of JBK-75 precipitate-strengthened austenitic steel were examined using the method of high-pressure thermal hydrogen charging and tensile tests. The hydrogen content in the charged specimens was 25.2 wppm. At the condition of η phase-free precipitating, the HD of the steel increased with increasing γ size, fine spherical γ dispersively dis-tributed was beneficial to improve the hydrogen-resistant property. η-phae precipitated at grain boundary increased HD tendency, while intragranular cellular η had less effect on it. Fine austenitic gruin Aize was beneficial to decrease the HD. At the condition of η phase-free precipitating, both hydrogen changed and uncharyed specimens of the steel fractured in ductile transgranular mode, whilst hydrogen promoted the intergranular fracture when obvious η precipitates were found.
关键词:
hydrogen damage
,
null
,
null
崔文广
,
高岩磊
,
周二鹏
,
梁惠霞
,
牟微
高分子材料科学与工程
采用熔融共混法制备出了高抗冲聚苯乙烯(HIPS)/高性能纳米氢氧化铝(纳米CG-ATH)复合材料,研究了高性能纳米氢氧化铝的加入量对高抗冲聚苯乙烯阻燃性能、力学性能和热稳定性的影响.结果表明,高性能纳米氢氧化铝的加入有助于提高高抗冲聚苯乙烯的极限氧指数、拉伸强度、弯曲模量和热稳定性,但对高抗冲聚苯乙烯的冲击强度会产生不利影响.加入量过多时,高性能纳米氢氧化铝在高抗冲聚苯乙烯基体中的分散性变差.
关键词:
高抗冲聚苯乙烯
,
高性能纳米氢氧化铝
,
纳米复合材料
材料科学技术（英文）
X80 pipeline steel produced by TMCP has high strength and high toughness with ultrafine grain microstructure. The microstructure coarsens and the toughness worsens at the coarse grained (CG) HAZ apparently after weld simulation. The experimental results indicated that the bainitic ferrite and the second phases formed at cooling are differently as the variation of carbon in base metal. In low carbon steels, the bainitic ferrite laths are long and narrow, the second phases are complex including residual austenite, martensite, the M-A constituent and the Fe3C carbide. The formation of Fe3C carbide is the main reason of the poor toughness in CG HAZ. The ultralow carbon in base metal, however, can improve the CG HAZ toughness through restraining the formation of carbides, decreasing the M-A constituent, increasing the residual austenite content, which are beneficial to the CG HAZ toughness.
关键词:
X80 pipeline steel;weld simulation;CG HAZ;ultralow carbon;Fe3C;carbide
Xiaohuai XUE
,
Luhai WU
,
Bainian QIAN
,
Jingli LI
,
Songnian LOU
材料科学技术（英文）
X80 pipeline steel produced by TMCP has high strength and high toughness with ultrafine grain microstructure. The microstructure coarsens and the toughness worsens at the coarse grained (CG) HAZ apparently after weld simulation. The experimental results indicated that the bainitic ferrite and the second phases formed at cooling are differently as the variation of carbon in base metal. In low carbon steels, the bainitic ferrite laths are long and narrow, the second phases are complex including residual austenite, martensite, the M-A constituent and the Fe3C carbide. The formation of Fe3C carbide is the main reason of the poor toughness in CG HAZ. The ultralow carbon in base metal, however, can improve the CG HAZ toughness through restraining the formation of carbides, decreasing the M-A constituent, increasing the residual austenite content, which are beneficial to the CG HAZ toughness.
关键词:
X80 pipeline steel
,
null
,
null
,
null
,
null
关长斌
,
赵玉成
,
陆文明
复合材料学报
doi:10.3321/j.issn:1000-3851.2008.01.013
采用于法混炼工艺制备了CG混合纤维(炭纤维和玻璃纤维)/橡胶复合材料,并在热模拟实验机上测定其蠕变曲线和应力松弛曲线,对其黏弹性进行了研究.结果表明:当CG混合纤维体积分数小于15%时,可提高橡胶的抗蠕变和抗应力松弛性能;而当CG混合纤维体积分数大于15%时,抗蠕变和抗应力松弛性能开始下降.理论推导表明:CG混合纤维/橡胶复合材料的蠕变与应力松弛在数值上互为倒数关系.
关键词:
CG混合纤维
,
橡胶复合材料
,
黏弹性
,
蠕变
,
应力松弛
万耿平
,
孙莺莺
,
赵季若
,
冯莺
高分子材料科学与工程
利用氯化原位接枝方法在聚乙烯(PE)主链上接枝丙烯酸-2-羟基乙酯(HEA),制得聚乙烯氯化接枝丙烯酸-2-羟基乙酯,记作:CPBc-cg-HEA.以红外光谱(IR)和核磁共振氢谱(1H-NMR)对其结构进行了分析;同时讨论了反应条件,包括反应温度,产物氯含量,原料配比以及氯气流量对产物接枝率的影响.结果表明,反应温度为110℃时,接枝率较高;CPE-cg-HEA的接枝率随HEA用量增加而提高,当HEA加入量达4～8份时,接枝率较高;随着氯含量的增加,反应时间延长,产物接枝率逐渐增大.
关键词:
氯化原位接枝
,
聚乙烯
,
丙烯酸-2-羟基乙酯
,
核磁共振氢谱
,
接枝率
Superconductor Science & Technology
In this paper we report the transport properties of c-axis-oriented superconducting La(1.44)Nd(0.4)Sr(0.16)CuO(4) films on LaSrAlO(4) substrates with different thicknesses in various magnetic fields parallel and perpendicular to the c axis of the films. It is found that with decreasing film thickness there is a crossover from the parallel shift to fan-shape broadening in the resistive transitions. Moreover, for both field configurations, the flux pinning potential U(0)(H) of the film shifts upward with an order of magnitude with increasing in-plane compressive strain. These results indicate that the compressive epitaxial strain and strain-induced destabilization of the static charge stripes are important aspects for the promotion of superconducting transition temperature as well as the flux pinning potential.
关键词:
high-temperature superconductors;crystal thin-films;flux motion;la2-xsrxcuo4;strain;insulator;dependence;behavior
