材料期刊网

INFLUENCE OF INTERNAL HYDROGEN ON THE HYDROGEN EMBRITTLEMENT OF AUSTENITIC STAINLESS STEEL

Y Tan , D.H Zhouand J. Feng (Institute of Structural Mechanics , Chengdu 610003 , China)

金属学报(英文版)

The HE (hydrogen embrittlement) behavior of two kinds of austenitic stee Cr21Ni6Mn9 and 1Cr18Ni9Ti is reprted in this paper. The factors (temperc-ture/strain rate/stress concentration coefficient and purity of hydrogen) are restricted to the severe conditions under which HE is easy to occur. The concentmtion of in-ternal hydrogen in samples is changed by varying the time during which samples are placed in 24 MPa hydrogen at 473 K Then the tensile properties of the samples are tested. The results indicate that the degree of the hydrogen-induced plastic loss (L)of Cr21Ni6Mn9 is different with the internal hydrogen(CH). Howeven even when CH is as high as 70 PPm L is 15% and the fracture may be explained as a larpe amount of internal hydrogen hinders the cross-slip of dislocations when the steel is deforming.For the metastable steel 1Cr18Ni9Ti the hydrogen-induced plastic loss is severer than that of Cr21Ni6Mn9. When CH is 40 PPm its L is as high as 42%. The mechanism may be explained as a larpe amount of hyderpen decreases the stacking fault enerpy and brittle ε-phase is produed in the high CH areas.

关键词: austenitic stainless steel , null , null , null

钯与氢(H2,D2)反应的热力学性质研究

唐涛 , 郭淑兰 , 陆光达 , 陈虎翅 , 朱新亮

稀有金属 doi:10.3969/j.issn.0258-7076.2004.02.005

采用PVT方法精确测定了40～60目的海绵钯(Pd)粉末在5～50 ℃范围内吸放H2, D2的P-C-T 曲线.结果表明:25 ℃, 0.1 Mpa时H2, D2在Pd中的溶解度分别为75.8和70.4 ml(STP)·g-1 Pd;Pd与H2, D2反应的坪台热力学函数分别为:Δha=-18.7 kJ·mol-1 H, -17.6 kJ·mol-1 D, Δsa=-46.4 J·K-1·mol-1H, -49.6 J·K-1·mol-1D;ΔHd=21.3 kJ·mol-1H, 18.7 kJ·mol-1D, ΔSd=50.8 J·K-1·mol-1H, 49.1 J·K-1·mol-1D.H, D在α相的溶解热力学函数为:ΔHr→0=-6.5 kJ·mol-1H, -5.6 kJ·mol-1D;ΔSr→0=-53.5 J·K-1·mol-1H, -53.7 J·K-1·mol-1D.Pd-Q(Q=H, D)体系存在明显的迟滞效应, 升高温度可改善吸放氢循环的压力迟滞效应, 但不能消除.伴随迟滞效应的吉布斯自由能损失(Δgloss)在低于50 ℃时保持不变, 对Pd-H和Pd-D体系分别为1.28和1.25 kJ·mol-1H(D);当高于50 ℃时Δgloss分别减小约4%和11%.

关键词: 钯 , 氢同位素 , 热力学 , 迟滞效应

SPE水电解进行H/D同位素分离

孟建波 , 桑革 , 薛炎 , 曹伟 , 叶小球

应用化学 doi:10.3969/j.issn.1000-0518.2007.12.017

将固体聚合物电解质(SPE)水电解技术应用于H/D同位素分离,考察了电极材料、电流密度和温度对分离系数(α)的影响.在40 ℃、90×10-3 A/cm2条件下,得到IrRu/Nafion117/PbAg、IrRu/Nafion117/TiNi3、IrRu/Nafion117/Ni和C/Nafion112/Pt-TiO2三合一电极(MEA)的H/D分离系数α分别为4.49、3.48、3.14和4.53.对IrRu/Nafion117/PbAg电极研究结果为:电流密度分别为90×10-3、150×10-3和300×10-3 A/cm2,40 ℃时分离系数α分别为4.49、4.65、5.46,60 ℃时分别为3.76、4.11、4.38;温度分别为40、60和70℃,电流密度为90×10-3 A/cm2条件下,分离系数α分别为4.49、3.76、3.53,ln α～103/T的拟合直线为ln α=0.816×(103/T)-1.112.在40～70 ℃范围内反应的活化能-△Ha约为6 778 J/mol.结果表明,分离系数α随电流密度增加而增大,随温度升高而减小.此外,分析了Nafion膜中在H/D传输的同位素效应.

关键词: 固体聚合物电解质 , 水电解 , 电催化剂 , 氢同位素 , 分离

Structural parameters for hydrogen bonding networks formed in systems of (A)over-bar(a1) (D)over-bar(d1)-A(a2) D-d2 type

Chemical Journal of Chinese Universities-Chinese

Structural parameters of hydrogen bonded network formed in a model system of hydrogen bonding solutions were studied on the basis of the sol-gel partition theory. With the proposed method, the gelation condition, the theoretical and numerical results of these structural parameters were presented in the cases that there exist the activity differences between the proton-donors and proton-accepters. It is shown that the activity difference can give rise to influence on the hydrogen bonded networks. This provides a possible theoretical clue to control the hydrogen bonded networks.

关键词: hydrogen bonded network;structural parameters;sol-gel phase transition;thermoreversible gelation;fluids;water;polymers;models

基于3D打印的微微型混合工质J-T制冷器实验研究

王昂 , 公茂琼 , 吴剑峰

工程热物理学报

微微型节流制冷器在微小元件和制冷应用中有广阔的前景.本文通过对搭建一微型压缩机驱动的微型混合工质节流制冷器系统,取得初步结果.该微微型J-T节流制冷器采用3D打印技术,通道特征尺寸为0.1 mm,突破了传统机械加工的极限.通道深宽比达到8:1.初步实验表明,微微型J-T节流制冷器达到了230 K温区.由于采用微型压缩机驱动,系统结构紧凑,可在便携生物储存设备、低温医疗以及电子器件冷却等领域应用并能长期运行.

关键词: 微微型节流制冷器 , 混合工质 , 3D打印

THERMAL FATIGUE AND FRACTURE MECHANICS ANALYSIS OF GREY CAST IRON

GUO Chengbi ZHOU Weisheng Dalian Institute of Technology , Dalian , Liaoning , China Professor , Dept.of Shipbuilding , Dalian Institute of Technology , Dalian , Liaoning , China

金属学报(英文版)

The in-phase and out-of-phase thermal fatigue,the C-P type and P-C type isothermal fa- tigue of grey cast iron were experimentally studied.The fatigue life was evaluated analytically by using the elastic-plastic fracture mechanics method(mainly J integral).The results of ex- periments and calculations showed that the lifes of in-phase and C-P type fatigue are longer than that of out-of-phase and P-C type fatigue respectively within the same strain range. This is in contrast to the results of other materials such as low carbon steel.On the other hand, the predicted lifes are consistent with experimental results.This suggests that J integral as a mechanics parameter for characterizing the thermal fatigue strength of grey cast iron and the mechanics model and the calculation method developed here are efficient.A parameter ΔW_1 was proposed from energy aspect to characterize the capacity of crack propagation. The isothermal fatigue life is the same as the thermal fatigue life for identical ΔW_1 values.

关键词: grey cast iron , null , null

X70管线钢J1d和K1a与V型缺口Ak关系研究

朱杰武 , 柳永宁 , 许雁 , 冯耀荣

机械工程材料 doi:10.3969/j.issn.1000-3738.2005.06.007

在不同温度下测试了X70管线钢动态断裂韧度K1d、J1d和止裂韧度K1a以及夏氏V型缺口冲击韧度Ak,对三者的关系进行了分析.结果表明:温度和加载速率都对断裂韧度产生影响;加载速率变化引起的韧-脆断裂转变具有热激活特征,在热激活分析基础上,在应力强度因子速率K=15 MPa·m1/2s-1条件下,得出断裂韧度、止裂韧度和冲击韧度三者的关系:Ak=4.84×106T-2.8K1d(或K1a).可以用小试样Ak数据计算得到K1d和K1a.

关键词: 管线钢 , 断裂韧度 , 止裂韧度 , 韧-脆断裂转变

H_2气氛保护热处理1J50组织结构与性能的研究

孙建春 , 盛光敏 , 陈登明 , 周安若 , 朱光俊

功能材料

1J50软磁合金的性能主要是通过H_2热处理获得的,在1130℃和H2气氛保护下对冷轧态1J50软磁合金进行了热处理.运用MATS-2010SA软磁测试仪对处理前后1J50软磁合金的磁性能进行了检测,运用金相显微镜、XRD等手段对处理前后1J50软磁合金的组织结构进行了分析.结果表明,通过H_2热处理,1J50软磁合金的矫顽力显著降低,起始磁导率和最大磁导率提高;组织结构发生明显变化,冷轧态1J50软磁合金组织为孪晶奥氏体,平均晶粒尺寸为200μm,处理过后,晶粒显著长大,平均晶粒尺寸为100μm;由于在600℃时采取了快冷,处理后1J50软磁合金中未出现大量FeNi相和FeNi_3相.

关键词: H2热处理 , 1J50 , 组织结构 , 性能

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

含铌Q275D热轧H型钢的研制

郭秀辉

钢铁研究

为保证莱钢Q275D热轧H型钢极限规格的-20℃冲击功值满足GB/T 700-2006要求,采用Nb微合金化结合再结晶控轧工艺试制了极限规格H400 mm× 200 mm×8 mm×13 mm的Q275D热轧H型钢.结果表明:试制产品的上屈服强度为360～368 MPa,抗拉强度为480～500 MPa,伸长率为32.5 ％～33.0％,平均冲击功为154～233 J,各项性能指标满足标准要求.

关键词: 热轧H型钢 , 再结晶控制轧制 , Nb微合金化