全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
材料工程  2009 

高频载荷下高强钢的超高周疲劳及热耗散研究

, PP. 49-53

Keywords: 超声疲劳,高强度钢,超高周疲劳,42CrMo4,100Cr6,热耗散

Full-Text   Cite this paper   Add to My Lib

Abstract:

应用超声疲劳试验技术,对两种高强度钢(42CrMo4,100Cr6)在20kHz频率下的超高周疲劳性能进行测试分析。实验结果表明两种钢的S-N曲线在106周发生了明显的变化,出现了水平渐近线。尽管23个42CrMo4钢试样用于1010周的疲劳试验,但在8.76×107循环周次以上,没有疲劳破坏发生,42CrMo4钢存在疲劳极限,而100Cr6钢的S-N曲线呈现台阶型。高精度热成像仪检测不同载荷条件下疲劳试样温度的变化结果显示温度的变化与试验材料和加载水平有关。试样温度的快速升高发生在超声疲劳试验的初期,温度的变化反映了材料内部的热耗散过程。裂纹萌生后,微裂纹处不可逆的局部塑性变形导致裂纹萌生区温度急剧升高,疲劳试样内部温度场的变化反映材料的疲劳损伤过程。SEM观察表明在长寿命区,疲劳裂纹常萌生于试样内部或次表层组织缺陷处。

References

[1]  MAYER H,PAPAKYRIACON M,ZETTL B,et al.Influence of porosity on the fatigue limit of die cast magnesium and aluminium alloys[J].International Journal of Fatigue,2003,(25):245-256.
[2]  BAYRAKTAR E,BATHIAS C,XUE H,et al.On the giga cycle fatigue behaviour of two-phase (α2+γ) TiAl alloy[J].International Journal of Fatigue,2005,(12):1263-1275.
[3]  JIANG L,WANG H,LIAW P K.Characterization of the temperature evolution during high-cycle fatigue of the ULTIMET super alloy,experiment and theoretical modeling[J].Metal Mater Trans,2001,32A:2279-2296.
[4]  ASTM STP 378-1964.Internal friction,damping,and cyclic plasticity[S].
[5]  PUSKAR A.The thermal activation of cumulative fatigue damage at ultrasonic frequencies[J].Ultrasonics,1977,(5):124-128
[6]  薛红前,陶华.超声疲劳试样设计[J].航空学报,2004,191(4):425-428.
[7]  PARIS P.The relationship of effective stress intensity,elastic modulus and burger-vector on fatigue crack growth as associated with "fish eye" gigacycle fatigue phenomena[A].Proceeding on the VHCF-3[C].Kyoto:2004.1-13.
[8]  ASTM STP1231-1994.An automatic ultrasonic fatigue testing system for studying low crack growth at room and high temperature[S].
[9]  WANG Q Y,BERARD J,RATHERY Y,et al.High cycle fatigue crack initiation and propagation behaviour of high cycle spring steel wires[J].Fatigue Fract Eng Mater Struct,1999,22(8):673-677.
[10]  BATHIAS C.How and why the fatigue S-N curve does not approach a horizontal asymptote[J].International Journal of Fatigue,2001,23 (1):143-151.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133