Development of Corrosion Crack Initiation Monitor Based upon Scanning Vibrating Electrode Technique

Research Project

Project/Area Number	60850018
Research Category	Grant-in-Aid for Developmental Scientific Research
Allocation Type	Single-year Grants
Research Field	機械材料工学
Research Institution	Kyoto University
Principal Investigator	KOMAI Kenjiro Faculty of Engineering, Kyoto University, Professor, 工学部, 教授 (70025948)
Co-Investigator(Kenkyū-buntansha)	MINOSHIMA Kohji Faculty of Engineering, Kyoto University, Instructor, 工学部, 助手 (50174107)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥8,200,000 (Direct Cost: ¥8,200,000) Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000) Fiscal Year 1985: ¥7,200,000 (Direct Cost: ¥7,200,000)
Keywords	Corrosion / Crack / Crack Initiation / Monitoring / Scanning Vibrating Electrode Technique / Corrosion Current Density / 画像処理 / 腐食ピット / モニター / 走査振動電極 / 腐食電位 / 腐食電流
Research Abstract	The monitor, which can evaluate the initiation and growth rate of localized corrosion including corrosion pit and corrosion crack in aqueous solution, has been developped. It spatially measures distributions of corrosion current density with time by using the computer controlled scanning vibrating electrode system. Distributions of current density on the samples including high-tensile strength steel weldments and model pit, i.e., austenitic stainless steels with spots filled with solder, are measured, and are displayed in three-dimensional plots and contour maps. The influences of differences between a sample and a micro-electrode on measured corrosion current density, and spatial resolution of anodic sites which correspond to localized corrosion are discussed. We also emphasize that computer image processing techniques provide powerful tools to analyze distributions of corrosion current density to extract localized corrosion sites.