J. Lukács

There are different documents and standards containing fatigue crack propagation limit or design curves and rules for the prediction of crack growth. The research work aimed (i) to measure basic data for limit curves on austenitic stainless steel (type 321), in corrosive environment and at elevated temperature; (ii) to determine the design curves based on statistical analysis of measured data and fatigue crack propagation law (Paris-Erdogan law).Experiments were performed on CT specimens in water solution (30 g CuSO4*5H2O + 10 g NaCl + 3 g NaOH in 1000 ml water), at 100 °C and 300 °C. Fatigue crack growth experiments were executed by constant load amplitude methods. The measured values were compared data can be found in the literature, at ambient and elevated temperature.The evaluation process consists of six steps and by means of the evaluated and selected values a simplified method can be proposed for determination of fatigue crack propagation limit curve. The determined limit curve represent a compromise of rational risk (not the most disadvantageous case is considered) and acceptable safety (uncertainty is known).

Fatigue Crack Growth Tests

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