tailieunhanh - Handbook of Corrosion Engineering Episode 2 Part 1

Tham khảo tài liệu 'handbook of corrosion engineering episode 2 part 1', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Acceleration and Amplification of Corrosion Damage 551 Figure Flowchart describing the logic of the stochastic process detector SPD technique. 552 Chapter Seven crevice initiation. The stochasticity technique was found to be particularly sensitive to the onset of crevice attack. By using a combination of noise analysis techniques it was possible to identify three distinct corrosion modes during these experiments pitting massive pitting and crevice Figures to contain the Ecorr measurements obtained during four consecutive experiments made with these S30400 steel cylindrical specimens equipped with the crevice collar and the results obtained by analyzing the voltage fluctuations by the SPD and R S techniques. At the end of these tests the specimens were removed from the electrolyte the PTFE collar was removed and the severity of the corrosion attack was assessed. In all four cases severe crevice attack was observed beneath the collar around the majority of the circumference. Knowing that a Brownian motion behavior is equivalent to a fractal dimension of as can be verified by the RS technique while the presence of persistence causes an increase in D it is possible to divide the results presented in Figs. to into two zones those with D and those where D . The transition between these two zones is quite evident in all four experiments carried out during this study. In the first experiment Fig. it occurred at approximately h in the test whereas it occurred at h for the second experiment Fig. h for the third Fig. and h during the fourth Fig. . The switch from antipersistence . D to persistence . D was accompanied in all four cases by a permanent transition of Ecorr toward values that were more cathodic by approximately 80 to 100 mV. It was also accompanied by a sudden burst of electrochemical energy that could be picked up by a scanning platinum probe with a commercial .