Pitting susceptibility and semiconducting properties of passive films of 18Cr-18Mn-2Mo-0.9N high nitrogen austenitic stainless steel
The effects of pH value and chloride ions concentration of the solution on pitting susceptibility and semiconducting properties of passive films formed on 18Cr-18Mn-2Mo-0.9N high nitrogen austenitic stainless steel (HNSS) were investigated using potentiodynamic polarization and capacitance measurement methods, respectively. The anodic polarization curves show that HNSS exhibits excellent pitting corrosion resistance in the solution with different pH values and chloride ions concentration, and the pitting corrosion resistance of HNSS decreases a little with decreasing the pH value or increasing the chloride ions concentration of the solution. The passive films formed on HNSS in the solution with pH values ranging from 1 to 9 or chloride ions concentration from 3.5 wt％ to 20 wt％ NaCl behave as n-type semiconductors. With increasing the pH value or decreasing the chloride ions concentration, the shallow donor and deeper donor densities decrease and the flat bland potential decreases, and the thickness of space charge layer increases. The deeper donor increases and then the second positive slope of straight linear region disappears with decreasing the pH value or increasing the chloride ions concentration of the solution, which can be attributed to the formation of Cr6+ is depressed.
high nitrogen austenitic stainless steel pitting susceptibility semiconducting properties passive films capacitance measurement
Li hua bing Jiang zhou hua Li zhen Zhang zu rui
School of Materials and Metallurgy, Northeastern University, Shenyang 110004, PR China
国际会议
青岛
英文
993-996
2009-10-09（万方平台首次上网日期，不代表论文的发表时间）