The characteristics of load frequency of corrosion fatigue crack growth rate for Ti–6Al–4V alloys

2016 ◽  
Vol 9 (4) ◽  
pp. 275-289
Author(s):  
A. Toshimitsu Yokobori ◽  
Hajime Nunokawa ◽  
Toshihito Ohmi ◽  
Shuichi Takagi ◽  
S. Takeda
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Corrosion Fatigue Crack ◽  
Load Frequency ◽  
Corrosion Fatigue Crack Growth

scholarly journals Effect of Various Factors Produced by Welding on the Corrosion Fatigue Crack Growth Rate

1987 ◽  
Vol 36 (12) ◽  
pp. 774-780
Author(s):  
Toshio Terasaki ◽  
Tetsuya Akiyama ◽  
Masatoshi Eto ◽  
Yasuhumi Matsuo ◽  
Masaharu Kusuhara
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

Effect of Hold-Time Interspersed With Cyclic Loading on Corrosion Fatigue Crack Growth Rate of a Steel in Sodium Chloride Solution

2018 ◽  
Author(s):  
Raghu V. Prakash ◽  
Dhinakaran Sampath
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Hold Time ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

Corrosion fatigue growth behavior of structural steels at low cyclic frequency is characterized by an increase in crack growth rate in the threshold and Paris regions, due to the simultaneous action of cyclic mechanical load (fatigue) and corrosive environment. Knowledge on the effect of load sequence on corrosion fatigue crack growth is important to set out the realistic design and prognosis criteria for components operating under corrosive environments. In this study, the corrosion fatigue crack growth rate under the effect of hold-time (1000s), at a maximum stress intensity factor (Kmax), interspersed during cyclic load on was studied experimentally on a Mn-Ni-Cr steel under 3.5% NaCl solution at a constant stress intensity factor range (ΔK) of 15 MPa √m; the corrosion crack growth rate was evaluated for three different frequencies of: 0.01, 0.1 and 1 Hz. As a result of hold time at the peak load, the exposure time for the crack-tip to interact with the environment increased, which could enhance the corrosion crack growth rates. To verify if this corrosion effect can be contained, electrode potential of (−) 850 mV and (−) 950 mV SCE was applied to the specimen to reduce the extent of corrosion contribution to crack growth rate. The fatigue crack growth rate (da/dN) increased when the frequency was decreased from 1 to 0.01 Hz at all electrode potentials. However, the crack growth rate at 0.01 Hz increased by an order of magnitude with a tensile hold at Kmax for 1000 s compared with the crack growth rate during continuous cyclic load for a given electrode potential. The crack growth rate reduced when the electrode potential was decreased to −950 mV SCE. The enhancement of corrosion fatigue crack growth rate with the introduction of a hold-time is explained using crack-tip strain rate assisted anodic dissolution.

Localised Corrosion Damage Based Fatigue Crack Extension Model of Aluminium Alloy with Prior Corrosion Damage

2015 ◽  
Vol 713-715 ◽  
pp. 2750-2753
Author(s):  
Liang Xi ◽  
Xiu Li Zhao ◽  
Chong Wei Shang ◽  
Guang Ming Kong ◽  
Si Yu Zhou
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Influence Factors ◽  
Corrosion Damage ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

A modified model was presented for describing corrosion fatigue crack growth rate of aluminum alloy accurately. Considering the local damage around the crack tip is more reasonable for accelerating crack growth rate under corrosive environment, a damaged influence factors which characterize the damage degree of local damage near the crack tip has been introduced to revise the corrosion fatigue crack growth rate, and the experimental results are in good agreement with predictions of amendment fatigue crack growth rate model. The proposed model based on damaged influence factors is reasonable, and proposed a theoretical reference for aluminum alloy damage tolerance analysis.

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