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EFFECT OF WAVEFORM ON CORROSION FATIGUE CRACK GROWTH
Author(s) -
KAWAI S.,
KOIBUCHI K.
Publication year - 1979
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1979.tb01327.x
Subject(s) - waveform , materials science , crack closure , growth rate , paris' law , stress (linguistics) , corrosion fatigue , corrosion , carbon steel , metallurgy , composite material , structural engineering , fracture mechanics , mathematics , electrical engineering , geometry , engineering , linguistics , philosophy , voltage
A study was made on the effects of stress rise time T 1 , maximum stress holding time T 2 , stress decreasing time T 3 and minimum stress holding time T 4 of a cycle on fatigue crack growth for a low alloy carbon steel in 3% NaCl solution. Measurements of the effective stress intensity range ratio U and observations of crack tip response were performed to clarify the causes of waveform effects. The results were summarized as follows; T 1 had a strong accelerating effect due to corrosive dissolution of the fresh surfaces of the crack which were formed during T 1 . The crack growth rate was enhanced as T 1 increased and reached a constant value (about 3 times that in air) after T 1 = 10s. The crack growth rate at low Δ K , however, decreased as T 1 increased more than T 1 = 1 s. T 2 , T 3 and T 4 decreased the crack growth rate. The extent of decrease not only depended on the period of T 2 (or T 3 , T 4 ), but also on Δ K and T 1 . A previously derived crack growth law which considered waveform and frequency effects, is also valid to a first approximation for the present results.