Fatigue strength of 316L-type stainless steel in simulated body fluids

The fatigue strength of commercial SUS316L stainless steel was studied in PBS(−) (phosphate buffer solution) with different dissolved oxygen contents and CPBS (a 0.9 mass% NaCl-containing citric phosphate buffer solution) with different pH levels, i.e., 5.0, 6.0, and 7.5. The results obtained are as follows. (1) The fatigue behaviour in PBS(−) was hardly affected by the dissolved oxygen content. (2) The fatigue strength in a high-cycle region was much lower in CPBS of pH 7.5 than in PBS(−) of pH 7.5. (3) The fatigue strength in CPBS decreased with decreasing pH from 7.5 to 5.0.

► The fatigue behaviour in PBS(−) was hardly affected by the dissolved oxygen content.
► The fatigue strength was much lower in CPBS of pH 7.5 than in PBS(−) of pH 7.5.
► The fatigue strength in CPBS decreased with decreasing pH from 7.5 to 5.0.
► No pits were observed at crack initiation sites or on the specimen surface.
► These results might be explained the anodic polarisation properties of the steel.