摘要
AbstractThe effect of applied potential on corrosion cracking of 40CrNi2Si2MoVA steel in3.5% NaCl solution is investigated by using slow strain rate tension (SSRT) and fracture mechanic methods at different potentials. It is found that the susceptibility to corrosioncracking of 40CrNi2Si2MoVA steel increases with applied potential. The total elongationto fracture εf of the steel, at-635 mV and -135 mV, is decreased to 54% and 49% ofthat iu air respectively. The crack propagation rate (da / dt)ll of the steel increases atanodic polarization (coupling Cu) and decreases at cathodic polarization. According to thevariation of corrosion cracking feature under different conditions and SEM fractographicanalyses, it is suggested that the corrosion cracking mechanism of 40CrNi2Si2MoVA steelshould result from the combined action of local anodic dissolution at the crack tip andhydrogen embrittlement.
AbstractThe effect of applied potential on corrosion cracking of 40CrNi2Si2MoVA steel in3.5% NaCl solution is investigated by using slow strain rate tension (SSRT) and fracture mechanic methods at different potentials. It is found that the susceptibility to corrosioncracking of 40CrNi2Si2MoVA steel increases with applied potential. The total elongationto fracture εf of the steel, at-635 mV and -135 mV, is decreased to 54% and 49% ofthat iu air respectively. The crack propagation rate (da / dt)ll of the steel increases atanodic polarization (coupling Cu) and decreases at cathodic polarization. According to thevariation of corrosion cracking feature under different conditions and SEM fractographicanalyses, it is suggested that the corrosion cracking mechanism of 40CrNi2Si2MoVA steelshould result from the combined action of local anodic dissolution at the crack tip andhydrogen embrittlement.
