An experimental investigation of fatigue crack growth of stainless steel 304L

✍ Scribed by S. Kalnaus; F. Fan; Y. Jiang; A.K. Vasudevan

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 663 KB
• Volume: 31
• Category: Article
• ISSN: 0142-1123
• DOI: 10.1016/j.ijfatigue.2008.11.004

✦ Synopsis

A series of fatigue crack growth experiments were conducted using round compact tension specimens of AISI 304L stainless steel under Mode I loading. The influences of the R-ratio (the ratio of the minimum load to the maximum applied load in a cycle), notch size, the tensile and compressive overloads, and the loading sequence on crack growth were studied. The results show that the material displays sensitivity to the R-ratio. The application of a tensile overload results in a short period of acceleration in the crack growth rate followed by a significant retardation in the crack growth rate. A compressive overload (underload) produces a short period of acceleration in crack growth and the magnitude of such an acceleration depends on the value of the loading amplitude of the constant-amplitude loading. Results from the two-step high-low loading sequence reveal a period of crack growth retardation at the beginning of the lower amplitude step, an effect similar to that of a single overload. Two existing crack growth models which are based on the stress intensity factor concept are evaluated using the experimental results. A two-parameter crack driving force approach together with a modified Wheeler's model is found to correlate well the crack growth experiments.