Data are presented on the low cycle fatigue characteristics in the life between approximately 10 and 103 cycles for a large number of steels including mild steels, high tensile strength steels, austenitic stainless steel, high carbon steels for rail and ultra high tensile strength steel.
In low cycle fatigue the power law relation between life and plastic strain range as proposed by Manson and Coffin has been amply verified, in more recent linear relationship were found when elastic strain range were separately plotted on log-log coordinates against life by Manson.
However these relationships were not correct with some high strength steels which consist of bainitic structure. This phenomena becomes remarkable with increasing the ultimate tensile strength, yield strength, and true fracture strength. The true stress at this turning point from linear relationship coincides approximately with ultimate tensile strength obtained by static tensile test.
The yield ratio, work hardening exponent are closely related with exponent of power law equation between life and plastic strain range.
These relations are predicted from micro-structural point of view, ferrite-pearlite or bainitic structure.
