Creep-rupture behavior of seven iron-base alloys after long term aging at 760 deg in low pressure hydrogen
Creep-rupture behavior of seven iron-base alloys after long term aging at 760 deg in low pressure hydrogen
复制标题
七种铁基合金在低压氢气中760℃长期时效后的蠕变断裂行为
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
J. R. Stephens
中科院分区：
文献类型：
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作者：
W. R. Witzke;J. R. Stephens
在低压氩气或氢气气氛中，在760/sup 0/C下对用于斯特林汽车发动机中的加热管应用的候选铁基合金进行3500 h的时效，以确定对机械行为的影响。评价的七种合金为N-155、19-9DL、316 SS、Nitronic 40、A286、Incoloy 800 H和RA 330。时效对合金晶粒尺寸没有明显的影响，但促进了晶粒和晶界中沉淀物颗粒的密度增加和生长。拉伸性能一般退化老化，与延展性和强度的变化受到晶粒结构的影响。老化也降低蠕变断裂强度，粗晶粒材料更容易受到强度损失。氢的存在下，在时效过程中没有显着贡献的蠕变强度退化的粗晶粒合金，但在细晶粒合金中导致广泛的强度损失。根据Mod I斯特林发动机的现行标准，N-155和19-9DL合金是本研究中强度足以在760/sup 0/C下使用加热管的唯一合金。
Candidate iron-base alloys for heater tube application in the Stirling automotive engine were aged at 760/sup 0/C for 3500 h in a low pressure argon or hydrogen atmosphere to determine the effect on mechanical behavior. The seven alloys evaluated were N-155, 19-9DL, 316SS, Nitronic 40, A286, Incoloy 800H, and RA330. Aging produced no appreciable changes in alloy grain size but did promote increased density and growth of precipitate particles in the grains and grain boundaries. Tensile properties were generally degraded by aging, with ductility and strength changes being influenced by grain structure. Aging also decreased creep-rupture strength, with coarse grain materials being more susceptible to strength loss. The presence of hydrogen during aging did not contribute significantly to creep strength degradation in the coarse grain alloys but did result in extensive strength losses in fine grain alloys. Based on current criteria for the Mod I Stirling engine, the N-155 and 19-9DL alloys were the only alloys in this study with strengths adequate for heater tube service at 760/sup 0/C.