Fe-26Cr-1Mo不锈钢在腐蚀疲劳过程中的瞬态电流行为

THE CURRENT TRANSIENT BEHAVIOUR OF Fe-26Cr-1Mo STAINLESS STEEL DURING CORROSION FATIGUE

一、引言在腐蚀性水溶液中,金属的力学疲劳损伤因电化学作用(如溶解效应和氢还原反应等)而加剧,反之,在腐蚀疲劳过程中,力学疲劳引起的塑性形变局部化又会增加电化学腐蚀。

Push-pull fatigue tests under plastic strain control were carried out with a high-purity ferritic stainless steel Fe-26Cr-1Mo in 1mol/L H_2SO_4 and 1mol/L NaCl solutions. The current transient behaviour during corrosion fatigue was different in these two solutions. Two sharp current peaks corresponding to maximum tensile and compressive strains respectively were observed in 1mol/L H_2SO_4. A sudden current drop or bump occurred as the test started with tension in H_2SO_4 solution. However, only one current peak, which occurred at approximately 50％ of the applied tensile strain, was found in each strain period in NaCl solution. The experimental results were explained in terms of the depassivation-repassivation process induced by strain cycling with the effect of chloride ions taken into account.