鋼の酸性水溶液中の腐食疲労における電気化学的挙動

抄録

Corrosion fatigue tests of mild steel have been carried out in 0.3N HCl, and electrochemical discussions are made on corrosion fatigue with the polarization characteristics measured by the rapid method. The anodic Tafel line is much affected by cyclic stresses, while the cathodic Tafel line is hardly varied. The increase of the corrosion current with the progress of cycles shows the similarity with the crack propagation. Therefore, the damage of corrosion fatigue is estimated by the corrosion current. The activation energy has the value of 14.0kcal/mol at the beginning of tests and tends to increase with the progress of cycles. On the other hand, the activities of metals much increase with the stress cycles, and in consequence the corrosion current is found to increase. The effects of cycle frequency are no more observed under frequency lower than 1100rpm. A linear relation is found between corrosion potential and logarithmic value of corrosion current. Therefore, the damage caused by corrosion fatigue can be also proved by the trends of corrosion potential.