| 摘要 |
PURPOSE:To observe the used material of an actual machine and to predict the remaining life of the metallic material directly and easily by measuring the shape of crystal grains of the metallic material quantitatively and arranging statistically the quantity of variation in the shape of the crystal grains with the lapse of time. CONSTITUTION:The shape of the crystal grains of the metallic material is measured quantitatively and the remaining life is predicted from the quantity of variation in the shape of the crystal grains. Namely, when the metallic material has a creep damage, the crystal grains expand and deform in the stress direction, so the variation in the shape of the crystal grains with the lapse of time is measured quantitatively to rearranged the quantity of the variation statistically. The replica film 3 of the actual machine member 2 is sampled by a replica method. Then this replica film 3 is observed through a microscope 4 and the crystal grains shape is measured by an image processor 5. Standard deviation based upon distributions of angles in the axial direction of the maximum diameter of, for example, the crystal grains and in the stress direction is found as the shape variation quantity which is a parameter. Then a personal computer 7 computes and evaluates the remaining life from the relation among the standard deviation, the standard deviation of a previously generated data base 6, and the creep damage quantity.
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