Microstructure Evolution Associated with a Superior Low-Cycle Fatigue Resistance of the Fe-30Mn-4Si-2Al Alloy
Microstructure Evolution Associated with a Superior Low-Cycle Fatigue Resistance of the Fe-30Mn-4Si-2Al Alloy
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DOI：
10.1007/s11661-015-3127-6
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发表时间：
2015-11-01
影响因子：
2.8
通讯作者：
Tsuzaki, Kaneaki
中科院分区：
文献类型：
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作者：
Nikulin, Ilya;Sawaguchi, Takahiro;Tsuzaki, Kaneaki
研究了对应变诱发马氏体相变敏感的Fe-30 Mn-4 Si-2 Al合金的上级低周疲劳抗力（N（f）> 8000次，总应变范围为2%）的微观组织演变。为了研究显微组织对合金低周疲劳行为的影响，在总应变范围为2%的条件下进行了一系列中断疲劳试验。一个特征软化阶段，其次是二次硬化观察循环加载过程中所研究的合金。这种软化与持久的Luders带形成和Luders带到应变诱导ε-马氏体的转变所造成的应变局部化被发现有一个关键的作用，在延迟疲劳断裂的合金正在研究。因此，涉及Luders带和ε-马氏体形成的连续转变过程与中间堆垛层错能（SFE）（γ（SF）为14 mJ/m（2））相关，对于防止位错重新排列成能够加速疲劳损伤的高SFE（γ（SF）高于20 mJ/m（2））合金所固有的壁/通道和亚结构是必要的。然而，缓慢的马氏体相变动力学是必要的，以延迟ε-马氏体的形成与疲劳裂纹的发展和扩展在具有非常低的SFE的合金中。(C)矿物、金属和材料协会和ASM国际2015
The microstructure evolution responsible for the superior low-cycle fatigue (LCF) resistance (N (f) > 8000 cycles at a total strain range of 2 pct) was studied in the Fe-30Mn-4Si-2Al alloy susceptible to strain-induced martensitic transformation. To investigate the microstructure effect on the LCF behaviors of the alloy, a series of interrupted fatigue tests at total strain range of 2 pct were carried out. A characteristic softening stage followed by the secondary hardening was observed during cyclic loading of the studied alloy. This softening is associated with the strain localization caused by persistent Luders bands formation and the transformation of Luders bands into strain-induced epsilon-martensite is found to have a key role in the delayed fatigue fracture of the alloy being studied. Therefore, the continuous transformation process involving Luders bands and epsilon-martensite formation associated with intermediate stacking fault energy (SFE) (gamma (SF) of 14 mJ/m(2)) is necessary to prevent the rearrangement of dislocations into walls/channels and substructures inherent to high-SFE (gamma (SF) higher 20 mJ/m(2)) alloys capable to accelerated fatigue damage. However, sluggish martensite transformation kinetics is necessary to delay the formation of the epsilon-martensite associated with the development and propagation of fatigue crack in alloys with very low SFE. (C) The Minerals, Metals & Materials Society and ASM International 2015