The corrosionfatigue behaviour of 304 stainless steel was studied as afunction of grain size, sensitisation, cyclic load, H2SO4 concentration (1M-5 M) and in 5M H2SO4 + 1M NaCl. Parallel experiments were carried out in air. Sensitisation accelerated the corrosion fatigue in all solutions, while in air the fatigue behaviour was not affected. With the coarse-grained material, the fatigue resistance both in air and in solutions was generally lower than that obtained when using non-sensitisedjine-grained material. Although 1 M H2SO4 was a passivating solution, thefatigue lifefor the three conditions studied in it was shorter than in air. The decrease infatigue limit was approximately 40010.5 M H2SO4 solution wasfound to be the most aggressive solution, reducing the fatigue resistance very considerably and eliminating the fatigue limit. In 5 M H2SO4 + 1MNaCI the corrosion was greatly reduced and thefatigue resistance was generally better than that obtained in 5 M H2SO4, particularly for the sensitised material. The corrosion fatigue behaviour of stainless steel. is discussed in the light of the results of corrosion studies in absence of load and ofthefatigue behaviour in air.
Bibliographical noteFunding Information:
The support of the Electric Power Research Institute under contract No. RP 311-1 is gratefully acknowledged.