The Effect of Pitting Corrosion on the Fatigue Strength of 304 and 316 Stainless Steel Alloys

Pitting corrosion behavior of 304 and 316 stainless steel alloys was investigated in 3.5% NaCl solution containing 100ppm thiosulfate ion as pitting corrosion initiator. Experiments were performed using potentiodynamic polarization and potentiostatic techniques at room temperature. The shape, size, and pit depth of the formed corrosion pits were also determined using the metallurgical light microscope. The fatigue strength of the pitted samples (either single or multipitted) was determined using plain-bending fatigue test machine. The fracture surface was also investigated using scanning electron microscope (SEM). The results show that SS 304 is more susceptible to pitting corrosion and has lower fatigue strength than SS 316 for the unpitted alloys samples. For both alloys, the single pitted samples shows that a deterioration percentage in fatigue is of about 15% while the multi pitted samples shows a deterioration percentage in fatigue of about 33% compared to the unpitted samples. The crack through the specimen surface was noticed to be initiated from the pit and propagates in two perpendicular sides to each other.

並列關鍵字

Pitting Corrosion ； Fatigue Strength ； SS 304 ； SS 316

國際替代計量

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