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An on-line monitoring system for hydrogen distribution metallic wall caused by hydrogen permeation

Gang YU , Xueyuan ZHANG , Yuanlong DU

材料科学技术(英文)

Based on the electrochemical permeation technique and the patent by Du, an intelligent electrochemical measurement system for determination of the hydrogen distribution in the wall of hydrogenation reactor has been developed and tested. It consists of a PC computer, a single chip unit, an I/V converter and an electrochemical hydrogen probe. The construction of the electrochemical hydrogen probe is described and the features of the measured system are given. The diffusion coefficient of 2.25Cr1Mo steel determined with present system was in good agreement with the value in the literature. Experimental results of hydrogen concentration in a wall of hydrogen charged testing autoclave made of AISI 321 stainless steel are presented. The present system can intelligently display hydrogen amount-of-substance concentration and mass fraction concentration, hydrogen concentration distribution curves in steels, permeation current density curve. An intelligent detection technique can be provided for predicting the susceptibility to hydrogen-induced cracks owing to hydrogen permeation in the wall of hydrogenation reactor in the field.

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Studies on the construction parameter of an artificial occluded cell for in-situ inspection of the propagation rate of localized corrosion

Liangcai LEI , Fengping WANG , Yanmin GAO , Yuanlong DU

材料科学技术(英文)

An artificial localized corrosion system is assembled and some parameters related to the localized corrosion in active dissolution state (i.e., non-passive state) have been studied. The results showed that the developed electrochemical system can satisfactorily imitate a naturally formed localized corrosion and the coupling current can indicate the maximum localized propagating rate. In this artificial system, the anodic dissolution reaction followed the auto-catalytic mechanism. The localized corrosion current density was dependent on the area ratio R of the cathode to the occluded anode. While R was equal to or more than 6, the coupling current reached at a maximum value and did not alter with the increase in R-value. Therefore, R=7 is chosen as one of these optimum parameters used in constructing the system, with which the biggest galvanic current might be obtained. In contrast, the thickness of the polymer filler separating the occluded anode area from the bulk electrolyte solution and the volume of the occluded anode area did not affect the corrosion current obviously. They might affect the response time to approach a steady state.

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Research surveys of electrochemical sensors for in-situ determining hydrogen in steels

Gang YU , Xueyuan ZHANG , Yuanlong DU

材料科学技术(英文)

The principle, construction and application of two types of electrochemical sensors-amperometric and potentiometric are surveyed. Both types of sensors are very sensitive to changes in temperature. The accuracy of hydrogen measurement depends on both the precision of sensors developed and the reliable technique of installation and security of sensors. The two types of sensors have been used for in-situ determining hydrogen permeated in steels owing to a corrosive reaction, a hydrogen gas circumstance at elevated temperatures and high pressure or also a pretreatment process such as pickling and plating process, etc.

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Study of in-situ electrochemical SSCC/HE susceptibility probe

Xueyuan ZHANG , Enhou HAN , Yuanlong DU

材料科学技术(英文)

An in-situ probe technique with an outward attached type of electrochemical sensor for inspection and evaluation of the susceptibility to sulfide stress corrosion cracking (SSCC) and hydrogen embrittlement (HE) of pipeline/vessel was developed. The relationship between SSCC/HE susceptibility of steel UNS G10180 and UNS G11190 and I-H was determined by the measurement of the stable hydrogen permeation rate (I-H) and the study of SSCC/HE susceptibility of the above two steels in TM-01-77 solution. Environmental sensitive cracking (ESC) of UNS G10180 and UNS G11190 steels can be inspected, evaluated, judged by the combination with the microcomputer system (MCS)/periphery attachment and the designed software. The results give an important insurance for safety control of the pressurized pipeline/vessel operated in the environment with H2S.

关键词:

DU-Ti合金表面N+Ti+多层Ti/TiN复合膜的制备与耐蚀性

严东旭 , 刘天伟 , 龙重 , 白彬 , 张鹏程 , 黄河 , 郎定木 , 王晓红 , 朱建国

材料保护

采用单一的表面改性技术难以提高贫铀钛合金(Du-Ti)的耐蚀性能.采用等离子体浸没离子注入技术依次在Du-Ti合金表面注入N和Ti,再利用非平衡脉冲磁控溅射技术制备多层Ti/,TiN,研究了膜层的形貌、结构及耐蚀性能.结果表明:膜层厚约3μm,呈柱状结构,致密,但存在一些微缺陷,膜基结合紧密;膜层出现面心立方结构的TiN和密排六方的Ti,在DU-Ti合金界面形成了少量的UO2,没有铀的氮化物;膜层耐蚀性能较基体得到较大提高;微观缺陷是TiN层局部片状脱落的主要原因,外层TiN出现片状脱落后.注入层和内层Ti/TiN多层膜仍能有效保护基体.

关键词: 等离子体浸没离子注入 , 非平衡磁控溅射 , 复合膜 , DU-Ti合金 , 电化学腐蚀 , 耐蚀性

水平轴风力机专用翼型性能评估方法

李星星 , 杨科 , 张磊 , 刘强

工程热物理学报

本文提出了风力机翼型完整的性能参数体系和相应的评估方法,并以此评估了CAS-W1翼型与DU翼型的性能特征.对翼型性能的评估侧重于失速特性、非设计点特性和翼型气动性能的稳定性.评估结果表明,相对于DU翼型,CAS-W1翼型系列设计点性能和非设计点性能较好,但是失速特性和性能稳定性需要优化.

关键词: 风力机专用翼型 , 气动性能评价 , 失速特性 , 稳定性参数

液晶显示用新型偏光片紫外光谱特性研究

欧阳艳东 , 黄翀 , 余云鹏 , 林舜辉

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2003.04.020

通过测量ITO玻璃及偏光片对各波段紫外光的光谱特性,分析比较一般偏光片和防紫外偏光片F1225DU的紫外透射光谱,从而说明新型偏光片的防紫外特性.F1225DU对紫外线有比较好的吸收,能挡住各种波长的紫外光,起防止紫外光破坏液晶显示器件的作用.

关键词: 偏光片 , 紫外光 , 液晶显示器 , 透射光谱

150t RH装置内钢液的流动和混合特性及吹气管直径的影响

蒋兴元 , 魏季和 , 温丽娟 , 李波

上海金属 doi:10.3969/j.issn.1001-7208.2007.02.008

在几何相似比为1∶4的水模型上研究了150t RH装置内钢液的流动和混合特性及吹气管直径的影响.模型的吹气管内径分别为0.10、0.15和0.2 cm.所得结果表明,该装置的环流量计算式为:Qlp=0.0291Qg0.323Du0.65Dd0.84(t/min),式中Qg-提升气体流量, Nl/min;Du和Dd-上升管和下降管内径,cm.在给定的Qg、Du和Dd下,吹气管直径din的变化对液体的流态没有显著影响,环流量则略有改变,在(0.40~0.80)cm的范围内,Qlp=0.0304Qg0.322Du0.651Dd0.839din0.07.在Du和Dd均为53 cm、din为0.60 cm的情况下,该装置内钢液的最大("饱和")环流量约为135.1 t/min,相应的Qg为2500 Nl/min.钢包内钢液的混合效果随Qg的增大迅速提高.增大din使混合时间τm(s)略有缩短,对应于0.10,0.15和0.20 cm的孔径,τm与搅拌功率密度ε(W/t)的关系分别为:τm ∞ε-0.497,τm ∞ε-0.493和Tm∞ε-0.476.

关键词: 150t RH装置 , 水模型 , 流动特性 , 混合特性 , 物理模拟 , 吹气管直径

钝尾缘翼型非定常气动特性及机理

张磊 , 杨科 , 徐建中 , 张明明 , 白井艳

工程热物理学报

钝尾缘翼型气动特性受到尾涡脱落的影响,在翼型DU 91-W2-250的基础上对称加厚得到了新钝尾缘翼氆DU91-W2-250_6,利用密网格进行了非定常气动特性的数值研究.在各个攻角下钝尾缘翼型气动特性都具有周期性的特点,具体的波动特征如波动幅值及周期等则受脱落涡的大小、脱落位置及尾迹宽度的影响,而升力系数波峰、波谷则分别出现在顺时针涡及逆时针涡脱落的时刻.

关键词: 翼型 , 钝尾缘 , 非定常

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