Characterization of stress corrosion crack growth of 304 stainless steel byelectrochemical noise and scanning Kelvin probe

来源期刊：中南大学学报(英文版)2010年第1期

论文作者：赵茹 张正 石江波 陶蕾 宋诗哲

文章页码：13 - 18

Key words：304 stainless steel; fatigue pre-cracking; electrochemical noise; stress corrosion cracking (SCC); scanning Kelvin probe

Abstract: The fatigue pre-cracking 304 stainless steel (SS) specimens with lengths of 1.002 mm (L-crack) and 0.575 mm (S-crack) were prepared. Their corrosion behavior was studied by electrochemical noise (EN) in 4 mol/L NaCl + 0.01 mol/L Na₂S₂O₃ solution under slow-strain-rate-testing (SSRT) conditions. Moreover, the characteristics of L-crack’s surface morphology and potential distribution with scanning Kelvin probe (SKP) before and after SSRT were also discussed. Compared with S-crack, L-crack is propagated and the features of crack propagation can be obtained. After propagation, the noise amplitudes increase with increasing stress and accelerating corrosion, the white noises at low and high frequencies (W_L and W_H) of the later stage are one order of magnitude larger than that at early stage in the current power spectral densities (PSDs). The potential PSDs also increase, but W_H disappears. In addition, the crack propagation can be demonstrated according to variation of probability distribution, surface morphology and potential distribution.

基金信息：the National Basic Research Program of China