LOW CYCLE FATIGUE OF MEDIUM CARBON STEEL DIN CK50

Abstract

The present work encompasses Low Cycle Fatigue (LCF) of the steel DIN CK50 with three conditions; as received (cold working), annealing at 850oC and 1000oC. The LCF tests carried out using standard specimens cantilever beam types. The results were confirmed that the steels sustained cyclic hardening, with annealing conditions more resistance to LCF. The values of fatigue strength exponent (b) are varying from (-0.07) to (-0.12) and fatigue ductility exponent (c) from (-0.51) to (-0.73), whereas these values within the general limitations of the metals. The number of transition cycle (NT) for annealing conditions is more comparing to the as received which emphasis that the annealed steels will withstand more cycles before introducing the plastic zone. The information extracted from engineering stress-strain curve; (σu/σy) as well as strain hardening exponent (n) can be used to estimate the behavior of the steel DIN CK50.