ステンレス鋼の腐食環境中引張試験と腐食電位変化

抄録

Measuring the electrochemical property is an effective way to know the corrosion resistance of metals. If metals covered by passive film receive tensile stress, corrosion resistance is expected to decrease because the passive film was damaged. To study the stress corrosion cracking, it is meaningful to know how the stress influences the corrosion potentials. In this study, we carried out a tensile test and a stress holding test of type 316 stainless steel in sodium chloride solution at room temperature. In the tensile test, tensile rate was set up as 2.0 mm/min. By measuring the corrosion potential during the tensile test, we proved that the corrosion potential decreased by about 400 mV from the yielding point to fracture. In the stress holding test, we measured the corrosion potential before and after passive film being damaged by tensile stress. The corrosion potential decreased by 168 mV by quickly applying 400 MPa. However, it recovered by 90 % in 20 minutes.