硼对金属间化合物Ni3Fe氢气诱发环境氢脆的影响

In this paper the tensile properties of both ordered and disordered Ni-24Fe and Ni-24Fe-0.03%B （wt%） alloys in gaseous hydrogen was investigated. The result shows that the ductility of the disordered Ni3Fe is significantly larger than that of ordered material in gaseous hydrogen. However, the ductility of ordered Ni3Fe doped with 0.03%B is nearly the same as that of disordered one indicating the obvious suppressing effect of boron on the H2-induced embrittlement. Based on the segregation behavior of boron in Ni3A1, it is proposed that the suppressing effect of boron in Ni3Fe on the H2-induced embrittlement is attributed to the segregation of boron on grain boundaries, thereby reducing the hydrogen diffusivity along the grain boundaries.     

有序无序转变对金属间化合物环境氢脆敏感性的影响

The mechanism involving the effect of disorder/order transformation on the environmental embrittlement in gaseous H2 is summarized. It is shown that there is no hydrogen embrittlement in disordered state of Kurnakov type intermetallics in gaseous H2. However, the H2-induced environmental embrittlement for the ordered alloy having identical chemical composition becomes severer as the degree of the order increases. The results of testing on the ion gage turned on and off during tensile testing show that the more sensitive to H2-induced hydrogen embrittlement for ordered alloy than disordered one is attributed to the fact that atomic ordering may accelerate the kinetics of the catalytic reaction to produce more atomic hydrogen. The results on simultaneous hydrogen charging show that disordered alloys embrittled as hydrogen atoms are forced into the material implying that the embrittlement of ordered alloy in gaseous H2 is also due to the acceleration of the kinetics of catalytic reaction. The above suggestion was further verified by the adsorption tests of Ni3Fe intermetallics powder. It is shown that the amount of chemically adsorbed hydrogen in ordered state is significantly larger than that adsorbed by the disordered alloy, indicating that the more sensitive to H2-induced embrittlement in the ordered state of alloy is essentially due to the accelerated catalytic reaction.     

有序度对Ni_4Mo合金在氢气中脆性的影响(英文)

1IntroductionNickel-based alloys containing 20 -30 wt % Mo isknown to be essential for corrosion resistance in re-ducing media[1],especially for resistance to HCl at alltemperatures and concentrations[2]. However , uponexposure to elevated temperatures in the range of600 -800 ℃,these alloys suffer an al most completeloss of roomtemperature ductility as a result of long-range ordering (LRO) to Ni4Mo .It is considered thatthe loss of ductility mainly results from the environ-mental embrittle…     

冷轧退火Fe3(Al，Cr，Zr)金属间化合物的室温环境脆性及择优取向

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｆｅ3Ａｌｂａｓｅｄａｌｌｏｙｓｅｘｈｉｂｉｔｈｉｇｈｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅ ,ｅｘｃｅｌｌｅｎｔｓｕｌｐｈｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅａｎｄｌｏｗｃｏｓｔｏｆａｌｌｏｙｃｏｎｓｔｉｔｕｅｎｔｓ.Ｈｏｗｅｖｅｒ ,ｔｈｅｓｅａｌｌｏｙｓｈａｖｅｎｏｔ ｙｅｔｆｏｕｎｄｗｉｄｅｓｐｒｅａｄａｐｐｌｉｃａｔｉｏｎｆｏｒｔｈｅｉｒｅｎｖｉｒｏｎｍｅｎｔａｌｅｍｂｒｉｔｔｌｅｍｅｎｔ[1～ 3] .Ｔｈｅｔｅｎｓｉｌｅｐｒｏｐｅｒｔｉｅｓａｎｄｅｎｖｉ ｒｏｎｍｅｎｔ…     

金属间化合物的环境脆性

In this paper the effect of alloying elements on the environmental embrittlement of Ll₂ type intermetallics is summarized. The results show that the ductilizing effect of boron doping in Ni₃Al is mainly to suppress the moisture-induced environmental embrittlement. The mechanism of this suppression effect is proved to be related to its severely reducing the hydrogen diffusivity along the grain boundaries. However, the boron doping in Co₃Ti alloys does not have the same effect of suppressing the environmental embrittlement. The different behavior of boron doping in Ni₃Al and Co₃Ti may be attributed to its different segregation behavior on the grain boundaries. Boron in Co₃Ti does not segregate on the grain boundaries and can not effectively reduce the hydrogen diffusivity along the grain boundaries. The moisture-induced environmental embrittlement of Co₃Ti alloy can be completely suppressed by the addition of Fe. It is proved by Auger that this suppression effect is due to its obvious reduction of the kinetics of the surface reaction with water vapor. Supported by the National Natural Science Foundation of China (Grant No.59895157,59081415,59371002,59771007)     

金属间化合物Nd_3Co的比热测定

我们对金属门化合物Nd3Co的比热在2K～35K的温度范围内进行了测量．观察到在8.5K、14K和25K．有三个磁性转变点。     

氧对焊缝金属吸氮机制的影响(英文)

通过测定 6种焊缝中的氮、氧含量 ,研究了氧对焊缝金属吸氮量的影响 ,发现液态金属在低氧 ([O] <0 .0 2 % )和高氧 ([O] >0 .0 3 % )条件下不同的吸氮机制 ,并且提出通过调整药芯成分 ,将焊缝氧含量控制在 0 .0 2 %～ 0 .0 3 %范围内 ,可使焊缝吸氮量最低 .     

锰基化合物Mn_(0.95)Co_(0.4)Ni_(0.6)Ge的多级磁相变

通过在MnCo_(0.4)Ni_(0.6)Ge中引入Mn空位得到化合物Mn_(0.95)Co_(0.4)Ni_(0.6)Ge,实现了AFM(TiNiSi)-FM(TiNiSi)-FM(Ni2In)-PM(Ni2In)多级相变;195K时在样品中观察到了从TiNiSi到Ni_2In的结构相变;255K时在样品Mn_(0.95)Co_(0.4)Ni_(0.6)Ge中实现了由顺磁(Ni_2In结构)向铁磁(TiNiSi结构)的结构相变;并且发现在外加磁场30kOe左右时引发场致相变;在195K(ΔB=5T)时产生了-17.8J/(kg·K)的磁熵变(材料制冷能力)。     

分子间氢键对化合物性质的影响

本文从几个方面讨论了分子间氢键对有机化合物性质的影响。     

氢在Fe3Al基合金中的渗透行为

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　ＩｒｏｎａｌｕｍｉｎｉｄｅｓｂａｓｅｄｏｎＦｅ3 Ａｌｈａｖｅｍａｎｙａｄｖａｎｔａｇｅｓｆｏｒｓｔｒｕｃｔｕｒａｌｕｓｅｓａｔｅｌｅｖａｔｅｄｔｅｍｐｅｒａｔｕｒｅｂｅｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅａｎｄｒｅｌａｔｉｖｅｌｙｌｏｗｍａｔｅｒｉａｌｃｏｓｔ.Ｈｏｗｅｖｅｒ,ｔｈｅｓｅａｌｌｏｙｓｈａｖｅｎｏｔｙｅｔｆｏｕｎｄｗｉｄｅｓｐｒｅａｄｕｓｅｂｅｃａｕｓｅｔｈｅｙｅｘｈｉｂｉｔｐｏｏｒｄｕｃｔｉｌｉｔｙａｎｄｂｒ…     

有序度对Ni4Mo合金在氢气中脆性的影响

The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly with the hydrogen pressure increasing, while that of the ordered alloy decreased rapidly with the hydrogen pressure increasing. However, the ductility of both disordered and ordered alloys reduced similarly seriously with the charging current density increasing. Therefore, the mechanism of order-induced embrittlement of Ni4 Mo alloy in hydrogen gas is supposed to be that atomic order accelerates the kinetics of the catalytic reaction for the dissociation of molecular H2 into atomic H.     

合金渗碳钢锥齿轮碳氮共渗的氢脆现象研究

通过对合金渗碳钢锥齿轮碳氮共渗的热处理研究,运用金相分析和氢脆试验等分析方法,对20CrMnTi合金渗碳钢锥齿轮碳氮共渗的氢脆现象进行了研究,找到了氢脆现象产生的原因,并提出了解决方案。     

Fe2O3-TiO2-SiO2光催化降解头孢氨苄试验研究

采用溶胶-凝胶法制备了复合型Fe2O3-TiO2-SiO2光催化荆利用FTIR、XRD等测试手段对其结构进行了表征。通过研究Fe“掺入量、催化荆用量、光催化降解时间及催化剂吸附实验、催化反应动力学实验，探讨了光催化剂降解头孢氨苄的条件。实验结果表明：在自然光照的条件下。该催化荆对试液中头孢氨苄的吸附率达48％。120min紫外光照射可使头孢氨苄降解率达90％，降解率随着催化剂用量增加而增加。Fe^3＋掺杂量为2．5％的催化荆催化活性最好。头孢氨苄光催化降解反应中。速率常数（K）与头孢氨苄的初始浓度Cod呈0．40级的动力学关系。     

Environmental embrittlement and preferred orientation of cold-rolled and annealed Fe3(Al,Cr,Zr) alloy at ambient temperature

The room temperature tensile properties of cold-rolled and annealed Fe₃(Al,Cr,Zr) alloy are similar to those of warm-rolled Fe₃Al alloys. The cold-rolled Fe₃(Al,Cr,Zr) alloy is also susceptible to test environments. It has been shown that the ductility in various environments decreases in sequence of oxygen-oil-air-distilled water. The results of X-ray diffraction analysis show that (211) preferred orientation of B2 phase appears in cold-rolled Fe₃(Al,Cr,Zr) alloy after recrystallization annealing. Supported by the National Natural Science Foundation of China (59895157) and the Natural Science Foundation of Shanghai Municipal Commission of Science and Technology (98ZE14020)