Very High Cycle Fatigue Strength of a High Strength Steel under Sea Water Corrosion
The effect of sea water corrosion on the gigacycle fatigue strength of a martensitic-bainitic hot rolled steel used for producing off-shore mooring chains for petroleum platforms was studied.Three different environments and conditions: (i) air; (ii) air after pre-corrosion,(iii) air under real time artificial sea water flow (in situ) were considered for testing smooth specimens under fully reversed tension between 106 and 1010 cycles.A drastic effect of corrosion was observed.For the fatigue life greater than 108 cycles,the fatigue strength is reduced by a factor more than 5 compared with non corroded specimens (virgin).Corrosion pits due to pre-corrosion,if any,or pits resulting from corrosion in real time during cyclic loading are the crack initiation sites.The calculation of the mode I stress intensity factor at hemispherical surface defects (pits) combined with the Paris-Hertzberg-Mc Clintock crack growth rate model showed that the fatigue crack initiation regime represents most of the fatigue life in the VHCF regime.Original additional experiments shew physical evidences that the fatigue strength in the gigacycle domain under sea water flow is mainly governed by the corrosion process with a strong coupling between cyclic loading and corrosion.
Gigacycle fatigue corrosion steel crack initiation crack growth
Thierr y PALIN-LUC Claude BATHIAS
Arts et Metiers ParisTech,I2M,UMR CNRS,Universite Bordeaux 1,Esplanade des Arts et Metiers,33405 Tal Universite Paris X,LEME,50 rue de Sevres,92410 Ville dAvray,France
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）