Vol.10, No3, 2010, pp.193-197
UDC  620.17 : 669.15-194

Growth of short cracks on smooth specimen is observed under different loadings in rotation-bending low-carbon, low alloyed steel, and pure-bending fatigue tests were additionally performed. Special features of interaction between the surface cracks and the microstructure of investigated steel are studied. A model is proposed for growth rate of surface cracks vs. their lengths by a system of parabolic and linear functions. Experimental results and models of both fatigue types are compared and some predictions are made, showing a reasonable agreement between the calculated by the model and experimentally obtained fatigue life.

Keywords: short fatigue crack, low-carbon, low alloyed steel, rotation-bending and pure-bending tests, modelling, fatigue life