Corrosion Behavior Of304Stainless Steel And Q235Carbon Steel By Electrochemical Noise Technique

In recent years, the industrial technology has developed vastly. At the same time,we need more performance steel to adapt the special working environment. How toensure the key material of steel safety in bad conditions is a big problem for ourresearchers, especially we should also save cost. According to different environment,we study the corrosion behavior of304stainless steel and Q235reinforced concreteby electrochemical method.In this paper, we detect the electrochemical corrosion noise of304stainless steelwith slow strain rate tensile (SSRT), and obtain the electrochemical noise (EN)characteristics of transgranular stress cracking corrosion (TGSCC) and intergranularstress cracking corrosion (IGSCC).The results of noise resistance、current standard deviation and noise amplitudeshow that TGSCC experiences four process: passivation-depassivation-afterpassivation/crack nucleation-crack extension, on the other hand, IGSCC experiencesthree process: metastable local corrosion-crack nucleation-crack extension. There aremore differences between TGSCC and IGSCC. For example, the current standarddeviation、noise amplitude and incident charge of IGSCC are much larger thanTGSCC. But they have the same characteristics when in the crack extension stage. So,the early crack ignition stage may be the important value for distinguishing these twocorrosion types.This paper also studies the corrosion behavior of Q235reinforced concrete incirculating cooling seawater.At first, we use simulation pore fluid as the corrodent, and find that the corrosionof Q235experiences passivation、film thicking and pitting. And then, we study thecorrosion on operating condition. At this time, the sample appears local corrosiontendency in a short time. The concrete did not work effectively because the thicknessis not enough and alkaline ion didn’t released.We directly distinguish the passivation and pitting using chaos analysis. Throughthe EIS and EN technology, we can obtain comprehensive corrosion information. Wavelet energy analysis is a very effective analysis means in the field ofcorrosion. We can judge the sample stay in which corrosion state by wavelet energysize and changing trend.