| 摘要 |
PURPOSE:To reduce irregularity and to enhance reproducibility, by holding a protruded surface formed part formed by pressing the back side of a resin coated metal plate having scores provided thereto to a hermetically closed state contacted with a predetermined amount of air and an aqueous electrolyte solution and measuring the release state of the resin layer caused by corrosion. CONSTITUTION:Two scores 2 are formed to the surface of a test piece 1, wherein a resin coating layer is formed to a base metal plate, in a depth reaching the base metal plate and a protruded surface part 3 having the intersecting point of said scores 2 as an apex is formed by pressing the base metal plate around said intersecting part from the back side thereof. Then, the test piece 1 is placed in a glass container 5 receiving a predetermined amount of air and an aqueous electrolyte solution 4 through an O-ring packing 6 so that the protruded surface part 4 is directed to the inside and the intersecting point of the scores 2 is positioned at the center and fixed by a clamping jig 7 while the apparatus is inverted to hold such a state that the aqueous solution is contacted with the protruded surface part 3 and the release state by corrosion between the coating layer and the metal plate is measured. |
