High Cycle Fatigue Performances of Advanced High Strength Steel CP800

A low carbon content and improved steel making practices have imparted advanced high strength steel (AHSS) CP800 with superior combination of strength, ductility and weldability. Its performance in fatigue, however, is not well understood. Stress-controlled high cycle fatigue (HCF) tests were conducted to obtain stress vs. fatigue life curve (S-N curve), and the fatigue limit of CP800. The follow HCF performances were obtained. , SRI1=1940MPa, b=-0.09972, Nc1=2.89×106, and R2= 0.88. The collected material data are used as a basis of comparison of CP800 with more common grades of structural steel. CP800 steel shows high strength, comparable ductility, and high fatigue limit level. The test results indicate that compare to that of lower strength common grades of structural steels, CP800 steel has a much higher fatigue endurance limit (say, 476MPa), about 0.6 of its tensile strength (TS). Thus, provides a distinct advantage.