| 摘要 |
PROBLEM TO BE SOLVED: To simply and surely detect a poorly nitrided part while relying on a color of the surface. SOLUTION: This detection method includes adding an oxidation treatment step of heating an endless hoop material (W) made from a maraging steel to 300 to 400°C in atmospheric air to a process of manufacturing an endless metal belt by the steps of solution-heat-treating the hoop material, controlling a peripheral length of the hoop material, and then subjecting the hoop material to aging treatment and nitriding treatment to impart a compressive residual stress to the surface of the hoop material; and simply and surely determining whether the nitriding treatment has been adequate or not, according to a color difference between a normally nitrided portion which shows a blue color and a poorly nitrided portion which shows other colors except the blue color. COPYRIGHT: (C)2009,JPO&INPIT
|
