Effect of hydrogen and frequency on fatigue behavior of SCM435 steel for storage cylinder of hydrogen station
Effect of hydrogen and frequency on fatigue behavior of SCM435 steel for storage cylinder of hydrogen station
复制标题
氢和频率对加氢站储气瓶SCM435钢疲劳行为的影响
DOI：
10.1299/kikaia.73.1358
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Y. Murakami
中科院分区：
文献类型：
--
作者：
Hiroyuki Tanaka;N. Homma;S. Matsuoka;Y. Murakami
对860°C淬火、580°C回火的SCM 435钢进行了频率为0.2、2和20 Hz的疲劳试验。还进行了频率在0.02 Hz和2 Hz之间交替切换的附加测试。采用浸渍法对试样充氢。充氢试样的疲劳寿命较未充氢试样有所降低。当试验频率f=20 Hz时，dα/dN<1.0×10- 7 m/cycle，f= 2 Hz时，dα/dN<4.0×10-7 m/cycle，f= 0.2Hz时，dα/dN<1.5×10-6 m/cycle，疲劳裂纹扩展速率da/dN加快。在f≤ 2 Hz时，dα/dN在ΔK<17 MPa时达到饱和。结果表明，氢环境下氢和试验频率对疲劳裂纹扩展速率的影响存在一个上限。在0.02Hz和2 Hz之间切换两个频率的试验表明，裂纹尖端附近的氢浓度显著影响疲劳裂纹扩展行为和裂纹形态。最显着的变化，在裂纹尖端附近的滑移带的充氢试样相比，未充电的标本是少和离散。
Fatigue tests on SCM435 steel quenched at 860°C and tempered at 580°C were carried out under the frequencies of 0.2, 2 and 20 Hz with specimens containing a small artificial hole. An additional test in which the frequency was alternatively switched between 0.02 Hz and 2 Hz was also carried out. Hydrogen charging to specimens was carried out by immersion method. The fatigue life of hydrogen-charged specimens decreased in comparison with that of uncharged specimens. The acceleration of fatigue crack growth rate da/dN was observed at dα/dN<1.0×10-7m/cycle in test frequency f=20 Hz, dα/dN<4.0×10-7 m/cycle in f=2Hz and dα/dN<1.5×10-6 m/cycle in f=0.2 Hz. The acceleration of dα/dN saturated at ΔK<17 MPa√m in f≤2Hz. It was found that there is the upper bound of the effects of hydrogen and test frequency on fatigue crack growth rate in hydrogen environment. The test with switching two frequencies between 0.02 Hz and 2 Hz showed that hydrogen concentration in the vicinity of the crack tip remarkably affects fatigue crack growth behavior and crack morphology. The most remarkable change of the slip bands around the crack tip was less and discrete in the hydrogen-charged specimens compared to uncharged specimens.