Fatigue strength of austenitic stainless steels applied to chemical tankers

The authors investigated the fatigue crack propagation behavior of solid austenitic stainless steels SUS304L, SUS316L and SUS316LN in order to conduct the characteristics of fatigue behavior of each stainless steel. Not only the constant stress amplitude tests, but also the load decreasing tests called by ΔKth test regulated by ASTM E647 were performed to identify the material constants of fatigue crack propagation. Comparison of the fatigue crack growth behavior of SUS304L, SUS316L and SUS316LN with mild steels was also performed. The authors also investigated the fatigue life of load-carrying type cruciform joints of austenitic stainless steels,which were modeled upon the lower end of vertically corrugated bulkhead of chemical tankers. Besides, the possibility of quantitative numerical simulation of the fatigue crack propagation for the stainless steels was also investigated. This simulation procedure was applied for the advanced effective stress intensity factor range based on a Re-tensile Plastic zone Generation (RPG) load and the fatigue crack closure phenomenon was quantitatively considered. The experimental results are compared with the numerical simulation results in this study and the validity of fatigue crack growth simulation procedure applied in this study is confirmed.