Microstructural Aspects of Low Cycle Fatigue of Pearlitic Steels

Abstract

The influence of the microstructure of pearlitic steels on their mechanical properties has been described. Formulae on the transition number of cycles and the plastic strain energy density as a function of the distance between cementite plates have been proposed. Experimental tests of the low cycle fatigue strength of pearlitic steels, characterized by different distances between the cementite plates, have been carried out. The results of experimental tests have been compared with the results of calculations. It has been found that the results of calculations comply well with experimental data.

A:

elongation

b, c:

fatigue strength and fatigue dutility exponent

e_r :

true strain

E:

modulus of elasticity

n’:

cyclic hardening exponent

N_t :

transistion number of cycles

N_f :

number of cycles to failure

s, t:

distance between cementile plates adn their thickness

Z:

reduction of area

ε’_f,C_f :

fatigur ductility and fatigue strength coefficient

ε_pε_e :

plastic and elastic strain strain amplitude

C_f :

true stress of failure

C_Y, C_Y :

yield and tensile strength

△W_p :

plastic strain energy density