EFFECT OF COMPOSITION ON HYDROGEN EMBRITTLEMENT IN Ni-Fe FCC ALLOYS

The ductility loss and threshold stress intensity,K_(IH)during hydrogen charging were measuredfor pure Ni and four Ni-Fe fcc alloys.The results show that ductility loss in 40Ni60Fe alloyand K_(IH)a 50Ni50Fe alloy have a minimum value.The variations of the amounts of hydride,hydrogen evolution and dislocation structure with composition have been investigated.The va-riation of hydrogen embrittlement susceptibility with composition measured by ductility lossand by K_(IH)or K_(IH)/K_C can be explained by means of the synthetical effects of amount ofhydride,solutionized hydrogen and the extent of dislocation planarity on hydrogenembrittlement susceptibility.     

Hydrogen embrittlement of high strength pipeline steels

A comparison was made between three API grade pipeline steels (X60, X80 and the X100 grade) from the point of view of their susceptibility to hydrogen embrittlement. The main aim was to determine whether the development of higher strength materials led to greater susceptibility to hydrogen embrittlement. This was achieved by straining at 2.8 × 10⁻⁵ s⁻¹ after cathodic charging. The results showed that there is a distinct susceptibility to loss of ductility after charging and this tends to increase with the strength level of the steel at a charging current density above 0.44 mA mm⁻². All three steels exhibited fine cracks parallel to the major rolling direction after charging and an increasing amount of brittleness on the fracture surface.     

新型炮钢回火碳化物析出规律及对高温力学性能影响

通过光学金相、扫描电镜及能谱和X射线分析研究了新型炮钢回火碳化物的析出规律，发现：当回火温度高于620℃，除渗碳体外，还析出合金碳化物Mo2C，并在640℃达到峰值。此外，对新型炮钢高温性能及使用寿命进行了分析和讨论。     

ATOMISTIC SIMULATIONS FOR Ni/Al INTERMETALLICS

ＡＴＯＭＩＳＴＩＣＳＩＭＵＬＡＴＩＯＮＳＦＯＲＮｉ／ＡｌＩＮＴＥＲＭＥＴＡＬＬＩＣＳＢＡＳＫＥＳＭ．Ｉ．（ＳａｎｄｉａＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｉｅｓ，Ｌｉｖｅｒｍｏｒｅ，Ｃａｌｉｆｏｒｍｉａ）Ａｂｓｔｒａｃｔ：ＡｌａｒｇｅｎｕｍｂｅｒｏｆＥ...     

16Mn钢在3％氯化钠水溶液中的阴极保护及其氢脆敏感性

本文用失重法和慢应变率法确定16Mn钢在3％氯化钠水溶液中适宜阴极保护电位区间,用扫描电镜观察慢应变拉伸断口形貌。结果表明:16Mn钢在3％氯化钠水溶液中适宜阴极保护电位区间是:-775mVSCE——-900mVSCE。阴极过保护电位下,16Mn钢将发生以沿晶脆断为特征的氢脆,而且保护电位越负,其氢脆敏感性越大。     

甲苯稀释对AlCl3-EMIC型离子液体电镀铝工艺氢脆性的影响

采用甲苯作为AlCl3-EMIC(1-乙基-3-甲基咪唑)型离子液体的稀释剂,其中纯态离子液体由物质的量比为2∶1的无水AlCl3和EMIC组成。对比了纯态和按稀释剂与离子液体体积比为1∶1稀释后电镀铝的外观、微观形貌和氢脆性。结果表明,采用甲苯稀释离子液体虽然可以降低镀液的黏度,改善镀层外观和微观形貌,但对离子液体电镀铝工艺的氢脆性有负面影响。     

低碳结构钢的氢脆行为研究

采用宏观、微观、纳米等手段,开展低碳钢在酸性环境中氢诱导作用对其力学性能影响进行研究。从研究结果可以看出,氢浓度和腐蚀扩展速率存在一定关系,低碳钢暴露于富氢酸性环境28天后,体积弹性模量显著降低。通过微观结构分析,发现氢渗透引起的大晶粒的变形、裂纹和氢鼓包是性能下降的主要原因。此外,通过在不同时间对试样的不同区域进行纳米压痕,确定了氢对晶粒纳米弹性和纳米硬度性能的影响。在宏观、微观和纳米层面上对受到氢损伤钢的力学性能的进一步研究,将对低碳结构钢的维护和使用寿命预测提供一种新途径。     

输氢管道工程设计要点

为加快我国氢气输送管道建设,确保管道安全运行,对氢气与常规天然气的特性进行了对比,分析国外相关标准要求,指出氢气管道工程设计的关键问题,详细论述了在管线工程设计时需要重点考虑的因素,如管材选用、断裂控制、结构设计、地区等级划分及设计系数选用、高后果区识别以及阀室间距等,并提出设计建议,为氢气管道工程设计提供参考。     

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 本文全面地研究了淬火温度和回火温度对25CrNiWV钢力学性能及金相组织的影响，确定了此钢种的最佳热处理工艺。     

30CrMnSiNi2A钢件镀硬铬的氢脆分析

本文叙述了用延迟破坏法试验超高强度钢(υb=1700MPa)不超过三次镀硬铬的氢脆情况。