| 摘要 |
PROBLEM TO BE SOLVED: To evaluate the stability of a surface protective film with high reliability by measuring the potential change of the surface protective film in a contactless and nondestructive method. SOLUTION: A liquid film of water or an electrolyte is formed on the surface of a metallic material covered with a surface protective film. The aging effect of potential when the liquid film disappears by drying is measured by a contactless method, and the stability of the surface protective film is evaluated on the basis of the measured result. In the stability evaluation of a rust layer for steel, it is evaluated as a stable rust layer when measuring potential is in a range of -0.05--0.35 V vs Ag-AgCl (a reference electrode). |
