The effects of microstructure and specimen size on the fatigue crack growth rate of an annealed 0.42 C steel were investigated under uniaxial fatigue loading in air. Although a dramatic fluctuation of crack growth rate was found in the propagation process of microstructurally small cracks, the mean value of crack growth rate can be evaluated by a simple mechanical parameter, σanl (l, crack length; n, constant), under high stress levels where small-scale yielding conditions are exceeded. This parameter is also effective for cracks larger than 1 to 2 mm under high stress levels, as long as the finite boundary effect of a specimen on the driving force of crack propagation is considered. The crack growth rate of the alloy was described as a function of stress amplitude and crack length in terms of two mechanical parameters, σanl and ΔK. The applicable conditions of the two parameters were discussed and manifested.
|Number of pages||9|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - Jan 1 2000|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys