有序度对Ni2Cr合金氢致脆断的影响

研究了环境气氛、动态渗氢及预渗氢对不同有序度Ni2Cr合金脆化的影响.结果表明,有序度对Ni2Cr合金在室温空气及氢气中的环境氢脆没有明显影响;动态渗氢拉伸时Ni2Cr合金存在严重的氢脆敏感性,无序和高度有序合金比部分有序合金脆化严重;预渗氢时,氢原子通过晶格扩散及晶界扩散进入合金,Ni2Cr合金氢脆敏感性随有序度的增大而减小.     

Effect of Strain Rate on Hydrogen Embrittlement Behaviour of Amorphous NiCrFeSiB Alloy

The effect of strain rate on hydrogen embrittlement behaviour of amorphous Ni-6.6Cr-2.6Fe-7.8Si-14.5B (at pct) alloy in 0.1 mol/L H2SO4 solution was studied by the methods of slow Strain rate testond electrochemical charging. The results show that fracture Stress of the alloy decreases with the decrease of Strain rate within a certain range. As a tentative explanation, the effect of strain rate on hydrogen embrittlement fracture stress was attributed to the interaction between hydrogen and the excess volume in amorphous alloys     

添加元素对Mg-3Si合金组织影响

采用扫描电镜、X射线衍射对合金组织进行观察,研究在Mg-3Si(质量分数/%,下同)合金陆续添加Zn,Nd,Gd,Y元素后微观组织演变规律。结果表明:Mg-3Si合金中Mg_2Si粒子具有初生和共晶两种明显不同的形貌;添加3%Zn元素后的Mg-3.0Si-3.0Zn合金中,初生Mg_2Si粒子粗化,共晶Mg_2Si粒子完全消失;在Mg-2.0Nd-3.0Zn-3.0Si合金中,Nd元素的加入能有效地细化初生Mg_2Si粒子并生成少量的Mg_(41)Nd_5粒子;继续添加Gd,Y元素后,在Mg-8.0Gd-4.0Y-2.0Nd-3.0Zn-3.0Si合金中的Gd_5Si_3和YSi等粒子急剧增加而Mg_2Si粒子含量大大减少。通过Thermo-Calc热力学软件的热力学计算表明:Gd_5Si_3,YSi的吉布斯自由能低,Gd,Y原子与Si更容易形成化合物。在Mg-8Gd-4Y-2Nd-3Zn-3Si合金中,Gd_5Si_3,YSi,Mg_2Si三种化合物的室温吉布斯自由能分别为-9.56×10~4,-8.72×10~4,-2.83×10~4J/mol,粒子的质量分数分别为8.07%,5.27%,1.40%。     

锌基合金氢脆行为研究进展

文章综述了Zn-Fe、Zn-Ni和Zn-Co等主要锌基合金电沉积过程中氢脆性的研究状况.指出锌合金镀层具有良好的性质,将会得到更广泛的应用.     

2091合金的显微组织与氢脆敏感性

用动态充氢慢拉伸试验研究了氢对2091,合金力学性能的影响,用离子探针分析氢在合金中的行为,用透射电镜研究了合金显微组织与氢脆敏感性的关系,结果表明,充氢使合金抗拉强度,延伸率和断裂寿命明显降低,氢易于在晶界处偏聚和富集造成晶界弱化,晶界沉淀相种类,形态和分布是影响合金氢脆敏感性的主要因素。     

The Effect of Hydrogen on Fluctuation Embrittlement of Aluminum

Technical Physics Letters - In this paper, we describe the main processes occurring during the generation of vacancies in aluminum in the presence of hydrogen by ab initio methods using the SCAN...     

Notch Severity Effect on Hydrogen Embrittlement of Type 4340 Steel

Hydrogen embrittlement of Type 4340 steel has been investigated by straining round-notchedspecimens in 105 Pa hydrogen atmosphere at a constent cross-head spead of 1.4x 10-4 mm/s.The circumferentially notched specimens exhibited a significant embrittlement when their me-chanical behaviour in hydrogen was compared with that in air. Although the effect of notch depthon fracture strength in air is negligible, an increase in the depth of notch increase susceptibility toembrittlement when testing in gaseous hydrogen. However, analysis of the effects is complicatedby the facts that (i) the specimens show some degree of notch severity even when strained inair and (ii) the behaviour is complicated by the localised plastic deformation that may occur forrelatively shatlow notches. Such effects are eliminated at high stress concentration factors, sothere is a systematic loss in fracture stress in hydrogen as the notch sensitivity increases fromK=2.6 to 5.7 (where a 87% reduction of fracture stress occurs) but a relatively stable value isthen reached even for very severe notching bj fatigue pre-cracking. Whether or not the effectis due to increasing concentration of hydrogen in the triaxial stress region ahead of the notch,there is no doubt that increasing the stress concentration makes hydrogen more effective as anembrittlement agent.     

Mechanical Alloying Effect on the Structure of Fe-Al-(Si) Alloy

The mechanical alloying effects on the structures of Fe71.3AI28.4(CeO2)0.3 and Fe73.3AI9.8-Si,e.e(CeO2)0.3 samples have been investigated mainly by Mossbauer spectroscopy and X-ray diffraction. It is found that with the increase of milling time, a substituting disordered a-Fe solution is formed gradually and almost completed after milled for 72 h. Further increasing milling time causes the atomic rearrangement within the powders. Correspondingly' the average lattice parameter and average crystalline size change until 72 h and remain constant after 72 h. The addition of Si leads to the higher disordered degree reflected in the smaller average hyperfine field and larger mean Square deviation.     

Fe-Al金属间化合物氢脆效应研究现状

Fe-Al金属间化合物具有良好的抗氧化、抗硫化腐蚀性能以及高温结构性质,而且质轻价廉,在航空航天、汽车工业、能量转换系统、过滤材料等领域具有广阔的应用前景,但在室温下易发生环境脆化,这也是其未能得到大规模应用的主要原因。本文在介绍Fe-Al金属间化合物特性的基础上,重点综述了Fe-Al金属间化合物氢脆行为及其机制的实验和理论研究进展,提出了今后的研究方向。     

Effects of Alloy Elements (C, B, Fe, Si) on the Ti-Al Binary Phase Diagram

1.IntroductionAlloyingisanimportantwaytoimprovetheprop-ertiesoftwofphase(cr2+ry)titaniumaluminideal-loys.Thealloyingelementswhichhavebeenstud-iedcanbesubdividedintothreegroupsX1(V,MnandCr),X2(Nb,Ta,MoandW)andX3(Si,C,B,N,P,Se,Te,NiandFe)['j.Smalladdi-tionsofX3elementsinthealloyshaveparticularlyreceivedmuchattentioninrecentyears['ro,'].ItwasreportedthatadditionofsmallamountsC,B,FeorSirefinesthemicrostructure[3~5?1o]limprovesroom-temperatureductilityl"']andincreasesoxida-tionresistance[…     

GH907合金疲劳蠕变和氢脆的显微分析

运用透射电子显微术分析研究了低膨胀高温合金ＧＨ９０７合金疲劳蠕变断裂试样和充氢试样的显微组织疲劳蠕变后合金显微组织发生了很大的变化，主要强人相γ变得没有规则，且片状ε相发生断裂；充氧后合我显微组织变化不大，使合金具有良好有抗氢脆的能力，但由于氢在晶界析出，晶界相与基体的结合力下降，合金的塑性，持久性能略有下降。     

Effect of δ Phase on Hydrogen Embrittlement of Inconel 718 by Notch Tensile Tests

The effect of δ phase on the hydrogen embrittlement (HE) sensitivity of Inconel 718 was investigated by conducting notch tensile tests. Notch tensile specimens with various precipitation morphologies of δ phase were prepared with different heat treatments, and hydrogen was charged into the tensile specimens before tensile tests via a cathodic charging process. The loss of notch tensile strength (NTS) due to the charged hydrogen was used to evaluate the hydrogen embrittlement sensitivity. The results show that δ phase has deleterious effect on NTSs, and the fracture of hydrogen-charged specimens initiated near the notch surfaces. The loss of NTS caused by precharged hydrogen can be greatly decreased by dissolving δ phase. δ-free Inconel 718 alloy is proposed for the applications in hydrogen environments.     

Effect of δ Phase on Hydrogen Embrittlement of Inconel 718 by Notch Tensile Tests

The effect of δ phase on the hydrogen embrittlement (HE) sensitivity of Inconel 718 was investigated by conducting notch tensile tests. Notch tensile specimens with various precipitation morphologies of δ phase were prepared with different heat treatments, and hydrogen was charged into the tensile specimens before tensile tests via a cathodic charging process. The loss of notch tensile strength (NTS) due to the charged hydrogen was used to evaluate the hydrogen embrittlement sensitivity. The results show that δ phase has deleterious effect on NTSs, and the fracture of hydrogen-charged specimens initiated near the notch surfaces. The loss of NTS caused by precharged hydrogen can be greatly decreased by dissolving δ phase. δ-free Inconel 718 alloy is proposed for the applications in hydrogen environments.     

飞机表面水基清洗剂对金属材料腐蚀及氢脆性能影响研究

研究了AHC-1及AHC-5两种飞机表面水基清洗剂对飞机表面典型金属材料的腐蚀性能及高强度钢氢脆性能的影响,探讨了应用缓蚀剂控制高强度钢氢脆的有效性以及用电化学极化法预测高强度钢在清洗剂中的氢脆倾向性.     

微量Sb和Mn对纯银材性能的影响

在99.995%银中添加0.005wt%Sb和0.003wt%Mn制成99.99%纯银材，进行机械性能测试，当ε=90%-97%时，在25℃下，强度σb=380MPa，硬度Hv=106保持365天稳定不变，即在高纯银中存在极微量的锑和锰，使Ag在结晶过程中出现少量的纳米颗粒，能细化Ag的晶粒，晶粒多，晶界界面增大，变形抗力增大，起到强化和稳定机械性能的作用。     

添加微量元素对Cu-Ni-Si合金性能的影响

分析了微量元素在改善Cu-Ni-Si合金强度同时又影响导电性的机理,综述了Zn、Cr、P、Al等微量元素对Cu-Ni-Si合金硬度、导电率等的影响规律,表明利用合金化规律在Cu-Ni-Si合金中添加不同的微量元素可以得到强度和导电率匹配良好的超高强度Cu-Ni-Si舍金.     

氢对Ni25Ti50Cu25记忆合金马氏体相变的影响

利用金相,X－射线,DSC,透射电子显微镜研究了氢对Ni25Ti50Cu25合金马氏体相变的影响,结果表明,当氢含量高时,氢与全金元素形成氢化物,与氧化物共存的李晶亚结构马氏体失去热弹性,当氢含量低329ppm时,氢固溶于合金中,随氢含量增加,马氏体相变温度降低,氢使马氏体在热循环过程中发生稳定。     

Crystal Structures of Zr2Mn12P7 and (Mo,Mn)12P7

Single-crystal x-ray diffraction was used to determine the crystal structures of the ternary phosphides Zr₂Mn₁₂P₇ (sp. gr. P6₃/m, a new structure type derived from the Zr₂Fe₁₂P₇ type,a = 0.9348(2) nm, c = 0.35755(5) nm, R = 0.039, R _w = 0.041) and (Mo,Mn)₁₂P₇ (sp. gr. P6¯, a new structure type derived from the Cr₁₂P₇ type, a = 0.93242(4) nm,c= 0.33807(1) nm, R = 0.048, R _w = 0.049).     

拉伸速率对Ni40 Ti50 Fe10合金环境氢脆的影响

研究了不同应变速率对Ni40Ti50Fe10合金环境氢脆的影响,并用扫描电子显微镜观察了拉伸断口的形貌.研究结果表明:Ni40Ti50Fe10合金在真空中的拉伸行为与应变速率无关,断口形貌主要是韧窝塑性断口.Ni40Ti50Fe10合金在空气中的塑性随着应变速率的降低而减小,断口形貌也从韧窝塑性断口转变为韧窝塑性断口和解理脆性断口的混合断口.Ni40Ti50Fe10合金在氢气中低应变速率拉伸时表现出明显的脆性,断口形貌主要为解理脆性断口.在高应变速率下(2×10-1s-1),Ni40Ti50Fe10合金在真空、空气和氢气中的塑性相近,说明在该应变速率下可以有效地抑制环境氢脆.Ni40Ti50Fe10合金的屈服强度不受应变速率和环境的影响.