Ni-Mo-V鋼の疲労き裂進展速度に及ぼす水素ふん囲気の影響
Ni-Mo-V鋼の疲労き裂進展速度に及ぼす水素ふん囲気の影響
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氢气氛对Ni-Mo-V钢疲劳裂纹扩展速率的影响
DOI：
10.2472/jsms.29.628
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
明躬 土方
中科院分区：
文献类型：
--
作者：
純夫 吉岡;出水 通之輔;道夫 熊沢;明躬 土方
对25 mm厚的Ni-Mo-V钢紧凑拉伸试样在实验室空气和氢气环境中进行了疲劳裂纹扩展试验。测定了不同频率和波形下的疲劳裂纹扩展速率，并通过断口观察讨论了疲劳裂纹扩展速率与疲劳断口形貌的关系，得出了表征氢气环境下疲劳行为的主要结论。(1)将氢气中疲劳裂纹扩展速率与应力强度因子范围的关系分为三个区域。在区域II和III中，观察到疲劳裂纹扩展速率有相当大的提高。(2)氢气中的疲劳裂纹扩展速率不受频率和波形的影响。(3)空气中疲劳断裂的断口形貌为正常的穿晶断裂，其中含有韧性条纹。然而，在氢气中的断裂形态显示在区域I中的沿晶断裂和在区域II和III中的解理断裂。解理断口上出现脆性条纹。(4)在空气和氢气中观察到韧性和脆性条纹的条纹间距和疲劳裂纹扩展速率之间的公平的对应关系。
Fatigue crack growth tests were conducted on 25mm thick compact tension specimens of Ni-Mo-V steels exposed to both laboratory air and hydrogen gas environments. The fatigue crack growth rates were determined under various frequencies and wave forms and the relation between the fatigue crack growth rate and fatigue fracture morphology was discussed by using fractographical observations.The main conclusions which characterize the fatigue behavior in the hydrogen gas environment are summarized as follows.(1) The relation between the fatigue crack growth rate and the stress intensity factor range in hydrogen gas was classified into three regions. In the regions II and III, a considerable raise in fatigue crack growth rate was observed.(2) The fatigue crack growth rate in hydrogen gas was not affected by frequency, nor by wave form.(3) The fracture morphology of fatigue failure in air showed normal transgranular fracture which includes ductile striations. However, the fracture morphology in hydrogen gas showed intergranular fracture in the region I and cleavage fracture in the region II and III. Brittle striations appeared on the cleavaged fracture surface.(4) A fair correspondence between the striation spacing and the fatigue crack growth rate was observed for ductile and brittle striations in both air and hydrogen gas.